Muscle hypertrophy relies on efficient protein synthesis, modulated by amino acid availability and signalling pathways such as mTOR, which activate muscle growth at a cellular level (Kimball et al., 2002). This study investigates the role of essential amino acids, particularly leucine and branched-chain amino acids (BCAAs), in promoting protein synthesis during resistance training. Using stable isotope labelling and molecular assays, protein synthesis rates were analysed in muscle biopsies post-intervention (Atherton & Smith, 2012). mTOR and associated pathways (e.g., S6K1) were assessed via Western blotting and RT-qPCR to quantify pathway activation (Drummond et al., 2009). Findings show a direct relationship between amino acid levels and increased anabolic signalling, providing data-driven insights into molecular responses essential for muscle adaptation (Phillips et al., 2005). This research underscores targeted amino acid supplementation as a potential strategy to enhance hypertrophic outcomes in resistance training (Tipton et al., 2001).

In this study we used a recently developed ex vivo-in vitro model to assess the effect of feeding older adults a casein protein hydrolysate (CPH) compared with non-bioactive non-essential amino acid (NEAA) supplement on Muscle Protein Synthesis (MPS) and Breakdown (MPB). Serum from six healthy older males following overnight fast and 60 min postprandial ingestion of CPH or NEAA (0.33 g.kg^-1 body mass) was used to condition C2C12 myotube media. CPH-fed serum significantly increased MPS compared to fasted serum. In addition, CPH-fed serum induced myotube growth and markedly suppressed atrogin-1, but not MuRF1, expression. Comparatively, no change in MPS, myotube growth and gene expression was observed following NEAA-fed serum treatment. CPH-fed serum from older adults stimulated de novo MPS, suppressed markers of protein breakdown and resulted in myotube growth, indicating a potential role for CPH as a dietary protein source to prevent age-related sarcopenia.

Sodium butyrate (NaB) is one of the short-chain fatty acids and is notably produced in large amounts from dietary fiber in the gut. Recent evidence suggests that NaB induces cell proliferation and apoptosis. The skeletal muscle is rich in plenty of mitochondrial. However, it is unclear how NaB acts on host muscle cells and whether it is involved in mitochondria-related functions in myocytes. The present study aimed to investigate the role of NaB treatment on the proliferation, apoptosis, and mitophagy of bovine skeletal muscle satellite cells (BSCs). The results showed that NaB inhibited the proliferation and promoted apoptosis of BSCs, and promoted mitophagy in a time and dose-dependent manner in BSCs. In addition, 1mM NaB increased the mitochondrial ROS level, decreased the mitochondrial membrane potential (MMP), increased the number of autophagic vesicles in mitochondria, and increased the mitochondrial DNA(mtDNA) and ATP level. The effects of the mTOR pathway on BSCs were investigated, and the results showed that 1mM NaB inhibited the mRNA and protein expression of mTOR and genes AKT1, FOXO1, and EIF4EBP1 in the mTOR signaling pathway, while the addition of PP242, an inhibitor of the mTOR signaling pathway, also inhibited mRNA and protein expression levels of mTOR, AKT1, FOXO1, and EIF4EBP1, and promoted mitophagy and apoptosis, which were consistent with the effect of NaB treatment. In conclusion, NaB might promote mitophagy and apoptosis in BSCs by inhibiting the mTOR signaling pathway. Our results would expand the knowledge of sodium butyrate on bovine skeletal muscle cell state and mitochondrial function.

Inadequate protein intake can impair protein balance and lead to skeletal muscle atrophy, impaired body growth, and functional decline. Foods provide both non-essential (NEAAs) and essential amino acids (EAAs) that may convey different metabolic stimuli to specific organs and tissues. In this study, we sought to evaluate the impact of six diets with various EAA/NEAA blends on body composition and the risk of developing tissue wasting in late middle-aged male mice. Mice consuming NEAA-based diets, although showing increased food and calorie intake, suffered the most severe weight loss. Interestingly, even moderate NEAAs prevalence was able to induce inflammatory catabolic stimuli, generalized body wasting and systemic metabolic alterations. Complete depletion of retroperitoneal white adipose tissue and a severe loss (>75%) of brown adipose tissue were observed together with muscle wasting. Conversely, EAA-based diets induced significant decreases in weight by reducing primarily fat reserves, but improved clinical parameters. Tissue wasting was caused by altered AA quality, independent of reduced nitrogen or caloric intake. Our results indicate that an optimized balance of AA composition is necessary for preserving overall bodily energy status. These findings are particularly relevant in the context of aging and may be exploited for contrasting its negative correlates including body wasting.

Resistance training is beneficial to adults for improving muscle strength and reducing the body composition. Nevertheless, little is known regarding online resistance training on anthropometric parameters and muscular strength (MS) in overweight female adolescents. This study aimed to examine the effects of online resistance training on anthropometric parameters and muscular strength (MS) in overweight female adolescents. This prospective, single-center, single-blinded, randomized controlled study included 60 overweight female adolescents who were divided into a control group (n=30) and an intervention group (n=30). The intervention group performed online resistance training, which focused on body weight training of 12 components (4 sets, 12 repetitions) for 45 min, three times per week, for 12 weeks. The intensity of training was 65–75%. Anthropometric parameters, including body weight (BW), body mass index (BMI), body circumference measurements (BCM), and muscle strength (MS), were assessed. All parameters were measured at weeks 0, 8, and 12. Within-group and between-group comparisons were performed. The results revealed improvements in MS, BW, BMI, and BCM in the intervention group. However, chest circumference was not significant. These findings suggest that online resistance training was effective in improving MS and reducing the body composition and circumference.

Physical frailty and sarcopenia (PF&S) are hallmarks of aging that share a common pathogenic background. Perturbations in protein/amino acid metabolism may play a role in the development of PF&S. In this preliminary study, 68 community-dwellers aged 70 years and older, 38 with PF&S and 30 non-sarcopenic, non-frail controls (nonPF&S), were enrolled. A panel of 37 serum amino acids and derivatives was assayed by UPLC-MS. Partial Least Squares Discriminant Analysis (PLS-DA) was used to characterize the amino acid profile of PF&S. The optimal complexity of the PLS-DA model was found to be three latent variables. The proportion of correct classification was 76.6 ± 3.9% (75.1 ± 4.6% for enrollees with PF&S; 78.5 ± 6.0% for controls). Older adults with PF&S were characterized by higher levels of asparagine, aspartic acid, citrulline, ethanolamine, glutamic acid, sarcosine, and taurine. The profile of nonPF&S individuals was defined by higher levels of α-aminobutyric acid and methionine. Distinct profiles of circulating amino acids and derivatives characterize older individuals with PF&S. The dissection of these patterns may provide novel insights into the role played by protein/amino acid perturbations in the disabling cascade and possible new targets for interventions.

We examined changes in skeletal muscle protein lactylation and acetylation in response to acute resistance exercise, chronic resistance training (RT), and a single endurance cycling bout. Additionally, we performed in vitro experiments to determine if different sodium lactate treatments affect myotube protein lactylation and acetylation. The acute and chronic RT study (n=12 college-aged participants) consisted of 10 weeks of unilateral leg extensor RT with vastus lateralis (VL) biopsies taken at baseline, 24-hours following the first RT bout, and the morning of the last day of the RT bout. For the acute cycling study (n=9 college-aged participants), VL biopsies were obtained before, 2 hours, and 8 hours after 60 minutes of cycling. For in vitro experiments, C2C12 myotubes were treated with varying levels of sodium lactate including LOW (1mM for 24-hours), HIGH (10mM for 24 hours), and PULSE (10mM for 30 minutes followed by 1 mM for 23.5-hours). Neither acute nor chronic RT significantly affected nuclear or cytoplasmic protein lactylation. However, cytoplasmic protein acetylation was significantly reduced following one RT bout (-15%, p=0.002) and chronic RT (-16%, p=0.006). Cycling did not acutely alter post-exercise global protein lactylation or acetylation patterns. Lastly, varying 24-hour lactate treatments did not alter nuclear or cytoplasmic protein lactylation or acetylation, cytoplasmic protein synthesis levels, or myotube diameters. These findings continue to support that exercise induces changes in skeletal muscle protein acetylation but not lactylation.

Background: Objective training load indexes (TL) used in resistance training lack of physiological significance. This study aimed to provide a muscle physiology-based approach for quantifying TL in resistance exercises (RE). Methods: Following individual torque-velocity profiling, fifteen participants performed isokinetic leg extension exercise sessions at low (C1), moderate (C2), and high (C3) intensities. Systemic and local physiological responses were measured, and sessions were volume-equated according to the "volume-load" (VL) method. Results: Significant differences were found between sessions in terms of mechanical work (

Background/Objectives: This study aimed to evaluate the effects of an 8-week combined plyometric and resistance training program on the physical fitness of adolescent girls aged 12 to 15 years. The objective was to determine whether combined training (CT) would yield greater improvements in performance measures compared to resistance training (RT) alone. Methods: Forty-seven adolescent girls were randomly assigned to either the CT group or the RT group. Performance measures such as the 20-meter sprint, squat jump, vertical jump, handgrip strength, and flexibility (sit and reach test) were assessed before and after the 8-week interven-tion. Changes in these measures were analyzed to compare the effects of the two training ap-proaches. Results: The CT group showed a significant reduction in sprint time (-6.5%) compared to the RT group (-4.1%), although the difference was not statistically significant. Squat jump height im-proved significantly by 5.6% in the CT group compared to 1.1% in the RT group (p < 0.05). Simi-larly, vertical jump height increased by 6.7% in the CT group and by 2.4% in the RT group (p < 0.05). Handgrip strength improved by 7.5% in the CT group and 4.6% in the RT group, with no significant differences between the groups. Flexibility showed slight, non-significant improve-ments in both groups. Conclusions: The findings suggest that combined plyometric and resistance training is more ef-fective in enhancing explosive power, specifically squat and vertical jump performance, in ado-lescent girls compared to resistance training alone. These results highlight the potential of com-bined training programs for improving overall physical performance in this population.

Nine crossbred finishing barrows randomly assigned to 3 dietary treatments were used to investigate the effects of dietary lysine on muscle growth related metabolic and signaling pathways. Muscle samples were collected from the longissimus dorsi of individual pigs after feeding the lysine-deficient, lysine-adequate, or lysine-excess diet for 5 weeks, and the total RNA was extracted afterwards. Affymetrix Porcine Gene 1.0 ST Array was used to quantify the expression levels of 19,211 genes. A total of 674 transcripts were differentially expressed (P ≤ 0.05); 60 out of 131 transcripts (P ≤ 0.01) were annotated in the NetAffx database. Ingenuity pathway analysis showed that dietary lysine deficiency may lead to (1) increased muscle protein degradation via the ubiquitination pathway as indicated by the up-regulated DNAJA1, HSP90AB1 and UBE2B mRNA, (2) reduced muscle protein synthesis via the up-regulated RND3 and ZIC1 mRNA, (3) increased serine and glycine synthesis via the up-regulated PHGDH and PSPH mRNA, and (4) increased lipid accumulation via the up-regulated ME1, SCD, and CIDEC mRNA. Dietary lysine excess may lead to (1) decreased muscle protein degradation via the down-regulated DNAJA1, HSP90AA1, HSPH1, and UBE2D3 mRNA, and (2) reduced lipid biosynthesis via the down-regulated CFD and ME1 mRNA.

Myostatin inhibition therapy has held much promise for the treatment of muscle wasting disorders. This is particularly true for the fatal myopathy, Duchenne Muscular Dystrophy (DMD). Following on from promising pre-clinical data in dystrophin-deficient mice and dogs, several clinical trials were initiated in DMD patients using different modality myostatin inhibition therapies. All failed to show modification of disease course as dictated by the primary and secondary outcomes measures selected: the myostatin inhibition story thus far, is a failed clinical story. These trials have recently been extensively reviewed and reasons why pre-clinical data collected in animal models has failed to translate into clinical benefit to patients has been purported. However, the biological mechanisms underlying translational failure need to be examined to ensure future myostatin inhibitor development endeavors do not meet with the same fate. Here, we explore the biology which could explain the failed translation of myostatin inhibitors in the treatment of DMD.

Leucine is an essential amino acid that cannot be produced endogenously in the human body and therefore needs to be obtained from dietary sources. Leucine plays a pivotal role in stimulating muscle protein synthesis along with isoleucine and valine as the group of branched-chain amino acids making them as one of the most popular dietary supplements for athletes and gym-goers. Individual effects of leucine, however, are not fully clarified, as most of the studies focused on the grouped effects of branched-chain amino acids. In recent years, leucine and its metabolites have been shown to stimulate muscle protein synthesis mainly via mammalian target of rapamycin complex 1 signaling pathway, thereby improving muscle atrophy in cancer cachexia. Interestingly, cancer research suggests that leucine may have either anti-cancer or carcinogenic effects. In the current manuscript, we aim to review leucine's roles in muscle protein synthesis, tumor suppression, and tumor progression, specifically summarizing the molecular mechanisms of leucine's action. The role of leucine is controversial in hepatocellular carcinoma, whereas its carcinogenic effects have been demonstrated in breast and pancreatic cancers. In summary, leucine being used as nutritional supplement for athletes needs more attention, as its oncogenic effects may have been identified by recent studies. Anti-cancer or carcinogenic effects of leucine in various cancers should be further investigated to have clear conclusions.

Skeletal muscle atrophy is one of the major side effects of high dose or sustained usage of glucocorticoids. Pyroptosis is a novel form of pro-inflammatory programmed cell death that may contribute to skeletal muscle injury. Trimetazidine, a well-known anti-anginal agent, can also improve skeletal muscle performance both in human and mice. We here showed that dexamethasone induced atrophy, evidenced by the increase of muscle atrophy F-box (Atrogin-1) and muscle ring finger 1 (MuRF1) expression , and the decrease of myotube diameter in C2C12 myotubes. Dexamethasone also induced pyroptosis, indicated by upregulated pyroptosis-related protein NLRP3, Caspase-1 and GSDMD. Knockdown of NLRP3 or GSDMD attenuated dexamethasone-induced myotube pyroptosis and atrophy. Trimetazidine administration ameliorated dexamethasone-induced muscle atrophy both in vivo and in vitro. Moreover, trimetazidine improved exercise tolerance, as evidenced by increased running distance and running time, as well as increased skeletal muscle mass in dexamethasone-treated mice. Mechanically, trimetazidine could reverse dexamethasone-induced activation of pyroptosis both in C2C12 myotubes and in mice. Taken together, our present study demonstrated that NLRP3/GSDMD pathway-mediated pyroptosis was involved in dexamethasone-induced skeletal muscle atrophy. Trimetazidine could partially alleviate dexamethasone-induced skeletal muscle atrophy, and increase the diameter of C2C12 myotubes via inhibiting pyroptosis. Thus, trimetazidine might be a potential therapeutic compound for the prevention of muscle atrophy in glucocorticoid-treated patients.

Hedgehog (Hh) proteins are prototypical morphogens known to regulate epithelial/mesenchymal interactions during embryonic development. In addition to its pivotal role in embryogenesis, the Hh signaling pathway may be recapitulated in post-natal life in a number of physiological and pathological conditions, including ischemia. This review highlights the involvement of Hh signaling in ischemic tissue regeneration and angiogenesis, with particular attention to the heart, the brain, and the skeletal muscle. Updated information on the potential role of the Hh pathway as a therapeutic target in ischemic condition is also presented.

We have previously demonstrated that the acute ingestion of essential amino acids may augment net protein balance in the elderly. Using a double blind, randomized controlled trial, our objective was to compare an experimental meal replacement enriched with essential amino acids (EMR) compared to a commercial meal replacement (Optifast®) provided once/day (q.d.) for four weeks on body composition and physical function in older, obese participants. Twenty-seven individuals (69±5 yrs; body mass index of 32±4 kg/m2) were randomly assigned to EMR (n=13) or Optifast® (n=15) supplementation. Measurements of body composition, skeletal muscle cross-sectional area (CSA), intrahepatic lipid and physical function were completed pre- and post-supplementation. Body mass, fat mass, and visceral fat mass were reduced with EMR but not altered with Optifast®. Thigh muscle CSA increased ( 4.1 ± 1.9 cm2, P = 0.03) with EMR but not Optifast®. There was a significant increase in the distance covered during the six-minute walk test with EMR ( 21±26 m) but no change in Optifast® ( 22±54 m). Improvements in body composition and physical function support the efficacious use of EMR-based meal replacements in the obese elderly.

After a Century it is time to turn the page on understanding of lactate metabolism and appreciate that lactate shuttling as an important component of intermediary metabolism in vivo. Cell-Cell and intracellular Lactate Shuttles fulfill purposes of energy substrate production and distribution as well as cell signaling under fully aerobic conditions. Recognition of lactate shuttling came first in studies of physical exercise where roles of driver and recipient cells and tissues were obvious. Moreover, the presence of lactate shuttling as part of postprandial glucose disposal has been recognized. Mitochondrial respiration creates the physiological sink for lactate disposal in vivo. Repeated lactate exposure from regular exercise results in adaptive processes such as mitochondrial biogenesis and other healthful circulatory and neurological characteristic such as improved physical work capacity, metabolic flexibility and cognition. The importance of lactate and lactate shuttling in healthful living is further emphasized when lactate signaling and shuttling are dysregulated as occur in illness and injury. Like a Phoenix, lactate rises again in importance in 21^st Century Biology.

(1) Background: During physical exercise, ventilation (VE) adapts to the intensity and characteris-tics of the effort. The breathing pattern is defined as the relationship between the tidal volume (VT) and breathing frequency (BF) for a given VE. The aim of this study was to evaluate whether inspiratory muscle training influenced the response of the breathing pattern during an incremen-tal effort in amateur cyclists. (2) Methods: 18 amateur cyclists completed an incremental test to exhaustion with gas analysis on a cycle ergometer and spirometry. Cyclists were randomly as-signed to two groups (IMTG=9; CON=9). The IMT group completed 6 weeks of inspiratory muscle training (IMT) using a PowerBreathe K3® device at 50% of the maximum inspiratory pressure (Pimax). The workload was adjusted weekly. After the 6-week intervention, the cyclists repeated the incremental exercise test with gas analysis and spirometry. The response of the breathing pat-tern was evaluated during the incremental exercise test. (3) Results: Pimax increased in the IMTG (p<0.05; +19.62%). Variables related to the breathing pattern response showed no differences be-tween groups after the intervention (EXPvsCON; p>0.05). Likewise, no differences were found in the IMTG after training (PREvsPOST; p>0.05). (4) Conclusions: IMT improved the strength of in-spiratory muscles and sports performance in amateur cyclists. These changes were not attributed to alterations in the response of the breathing pattern.

Ultrasound has become widely used as a mean to measure the rectus femoris muscle in the acute and chronic phase of critical illness. Despite its noninvasiveness and accessibility, its accuracy highly depends on the skills of the technician. However, few ultrasound phantoms for the confirmation of its accuracy or to improve technical skills exist. In this study, we created a novel phantom model and used it for investigating the accuracy of measurements and for training. Study 1 investigated how various conditions affect ultrasound measurements such as thickness, cross-sectional area, and echogenicity. Study 2 investigated if the phantom can be used for training of various health care providers in vitro and vivo. Study 1 showed that thickness, cross-sectional area, and echogenicity were affected by probe compression strength, probe angle, phantom compression, and varying equipment. Study 2 in vitro showed that using the phantom for training improved the accuracy of the measurements taken within phantom, and Study 2 in vivo showed the phantom training had a short-term effect on improving the measurement accuracy in a human volunteer. The new ultrasound phantom model revealed that various conditions affected ultrasound measurements, and phantom training improved the measurement accuracy.

Background: Muscle wasting is a common phenomenon in oncology and appears to be alleviated by exercise training. This study aims to determine the degree of aggressiveness of cancer-induced muscle wasting in two different phenotypic muscles, and whether exercise training can attenuate this muscle dysfunction. Methods: Fifty Sprague-Dawley rats were randomly assigned to four experimental groups, two control groups (sedentary and exercised) and two breast cancer model groups (sedentary and exercised) induced by 1-methyl-1-nitrosoureia (MNU). After 35 weeks of endurance training the animals were sacrificed and the gastrocnemius and soleus muscles were harvested for morphometric analysis. Results: A significant reduction in cross-sectional area (P < 0.05) was found in both muscles of sedentary tumor-bearing animals. Interstitial fibrosis was significantly higher in the gastrocnemius of sedentary tumor-bearing animals (P < 0.05), but not in the soleus. A shift from large to small fibers was observed in the gastrocnemius of sedentary tumor-bearing animals. Long-term exercise training was able to prevent this cancer-related mus-cle dysfunction. Conclusions: The Gastrocnemius muscle showed a very pronounced reduction in cross-sectional area and marked interstitial fibrosis in sedentary animals with tumors. The soleus muscle showed a less pronounced but significant reduction in cross-sectional area, and collagen deposition did not differ between tumor groups. These contrasting results confirm that can-cer-induced muscle wasting can affect specific fiber types, and specific muscles, namely fast glycolytic muscles, and that exercise training can act to improve it.

Muscle is one of the most critical organs for mammals, which governs multiple movement and physiological functions. Circular RNA (circRNA) is a kind of novel endogenous RNA without 5'-Caps and 3'-poly(A) structures formed by pre-mRNA's back-splicing. RNA binding proteins (RBPs) control the production and degradation of circRNA, help nucleus-cytoplasm transport and locate circRNA, and regulate circRNA translation. Therefore, circRNAs and the chaperoned RBPs play critical roles in muscle growth, development, and disease progression. In this review, we systematically characterize the possible molecular mechanism of circRNA-protein interactions. Also, we summarize the latest researches on circRNA-protein interactions in muscle development and diseases. Besides, we provide several valid prediction methods and experimental verification approaches. Our review reveals the importance of circRNAs and their protein chaperones and provides a reference for further study in this field.

Omega-3 polyunsaturated fatty acids (PUFAs) play a critical yet underappreciated role in muscle health, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Through a review of current literature, we analyze the effects of these nutrients on muscle protein synthesis, mass, strength, and recovery. Studies demonstrate that omega-3 PUFAs enhance muscle protein synthesis via the mTOR pathway and possess anti-inflammatory properties that may reduce muscle damage and atrophy, particularly in older adults. Their potential to improve muscle function and mitigate exercise-induced damage is also reviewed, highlighting relevance for athletes and active individuals. Further research on optimal dosages and long-term effects of omega-3 supplementation is needed, providing a basis for future studies and practical recommendations for leveraging these nutrients to support muscle health.

Astaxanthin (AX) is a carotenoid that exerts potent antioxidant activity and acts in the lipid bilayer. This study aimed to investigate the effects of AX on muscle atrophy-mediated disturbance of mitochondria that have a lipid bilayer. Tail suspension was used to establish muscle- atrophied mouse models. AX diet fed to tail-suspension mice prevented loss of muscle weight and decreased myofiber size in the soleus muscle. Additionally, AX improved down-regulation of mitochondrial respiratory chain complexes II and III in the soleus muscle after tail suspension. To confirm the AX phenotype in the soleus muscle, we examined its effects on mitochondria using Sol8 myotubes derived from the soleus muscle. We found that AX was preferentially detected in the mitochondrial fraction; it significantly suppressed mitochondrial complex III-driven production of reactive oxygen species in Sol8 myotubes. Moreover, AX inhibited the activation of caspase 3 via inhibiting the release of cytochrome c into the cytosol in antimycin A-treated Sol8 myotubes. These results suggested that AX inhibited mitochondrial oxidative stress through a mitochondria-mediated apoptosis pathway and thus prevented muscle atrophy.

The increasing demand for high-quality livestock products dictates to develop approaches to assessing the composition of the fatty acids (CFAs) and amino acids (CAAs) in animal tissues. The review considers the following issues: chromatographic methods for the determination of CAAs and CFAs of pig tissues; factors influencing the CAAs and CFAs of pig tissues; methods of regulating CAAs and CFAs of pork using nutritional factors; the effect of CAAs and CFAs on formation of meat properties. The main methods for determining CAAs or CFAs are the ion-exchange or gas chromatography, respectively. The total FA amount and individual FAs have significant effects on the tenderness, taste, color and juiciness of pork meat (due to the different melting points of particular fatty acids, formation of lipid oxidation products during cooking, etc.). Muscle proteins of pigs with regulated fatness differ also in CAAs (decreasing by increase in “pork fat” and decrease in the protein’s amount. The significance of this review is also determined by high popularity of pork in Russia and in a number of other countries of the world.

Functional ankle instability (FAI) results from multiple ankle sprains, causing a perceived sense of joint instability due to muscle and ligament imbalances. Neuromuscular training (NMT) is employed to enhance ankle stability in individuals with FAI. The study included 24 male university students with FAI, who underwent ankle NMT on three surfaces. OpenSim musculoskeletal model analyzed the effects on ankle muscle activity, kinetics, and kinematics. Utilizing repeated measures analysis of variance (ANOVA) and one-dimensional statistical non-parametric mapping (SNPM1d) to identify distinctions between training surfaces. NMT on foam cushion (FC) significantly enhanced tibialis anterior (TA) and gastrocnemius medial (GM) activation during walking compared to level-ground (LG) and artificial turf (AT) (p&lt;0.05). However, no differences observed for peroneus longus (PL), gastrocnemius lateral (GL), and peak ankle plantarflexion (PF). During jogging and fast running, post FC training increased TA, PL, GM, GL activation, and peak ankle PF moment (p&lt;0.05). Additionally, post FC training, subtalar mobility was significantly reduced (p&lt;0.05), and ankle joints exhibited greater dorsiflexion (DF) angles during jogging and fast running (p&lt;0.05). Consequently, selecting FC for short-term ankle NMT proves more advantageous in enhancing ankle stability among individuals with FAI, yielding a more positive impact on FAI improvement.

Introduction: The Elevation Training Mask 2.0 (ETM) has been introduced as a novel tool to allow for respiratory muscle training and altitude exposure during exercise that can improve performance and hematological markers in elite and well-trained athletes. Thus, the aim of the present study was to assess the effect of wearing ETM while training on erythropoietin (EPO), vascular endothelial growth factor (VEGF), peak oxygen consumption (VO2max), lactate, and 1000-m kayaking performance in elite Kayaking girls. Methods: Thirty elite Kayaking girls (14 to 18-year-old) were equally and randomly assigned into mask, no mask, and control groups. The mask and no-mask groups completed 8 weeks of repeated sprint training, while the control group performed their routine kayaking training programs. Pre- and post-training tests included EPO, VEGF, VO2max, lactate, and 1000-m kayaking performance. Results: 1000-m time trial significantly decreased for mask (p < 0.001) and control (p = 0.035) groups, and was significantly lower in mask group than control (p = 0.014) and no mask (p = 0.009) groups. EPO did not show any significant changes for all groups. VEGF was increased significantly for mask (p = 0.04) and no mask (p = 0.014) groups. Lactate was decreased significantly for mask group (p = 0.025). VO2max increased significantly for no mask group (p = 0.021). Conclusion: Wearing the ETM while participating in 8 weeks of repeated sprint training might improve specific blood markers and endurance performance, especially anaerobic pathways. Performing repeated sprint training while wearing ETM has the potential to enhance performance in Kayak racing.

Background : Drug treatments for gait disorders in post-stroke patients aim to reduce muscular hyperactivity. Analysis of muscle activity is essential to help clinicians understand these disorders. The aim of this study was to quantify changes in muscle synergies before (PRE) and after (POST) rectus femoris nerve block. Methods : Gait analysis of 8 post-stroke patients before and immediately after nerve block. Muscle synergies were quantified from electromyographic signals. We have selected: the account for variance indicating the robustness of the synergies, the recruitment selectivity index indicating the degree of multiplexing of the synergies, and the recruitment consistency index indicating the variability of the synergies. Results : A decrease in VAF is observed, suggesting a reduction in gait pattern robustness. We also note that spatial and temporal primitives are slightly different (IRC, IRS) in PRE vs. POST, and that their activation is more nested in POST than in PRE. Conclusions : The motor nerve block has not created new muscle synergies of the paretic limb during gait, but indicates that there is flexibility in motor organization. This method of quanti-fication may enable clinicians to assess the motor adaptation potential of their post-stroke patient.

External motivational stimuli have been shown to improve athletic performance. However, the neurophysiological mechanisms underlying this improvement remain poorly understood. This randomized crossover study investigated the effects of music and verbal encouragement on measures of muscle excitation and myoelectric manifestations of fatigue in the biceps brachii (BB) and brachioradialis (BR) muscles during an endurance task. Fifteen untrained (mean age 29.57 ± 2.77 years) and 13 trained individuals (mean age 32.92 ± 2.90 years) were included. The endurance task, performed to exhaustion, consisted of keeping the dominant arm flexed to 90 degrees while holding a dumbbell loaded to 80% of 1RM with a supine grip in three randomized conditions: standard, with self-selected music, and with verbal encouragement. The untrained subjects showed an increase in task duration of 15.26% (p < 0.003) with music and 15.85% (p < 0.002) with verbal encouragement compared to the condition without external stimuli. There were no significant differences in the myoelectric manifestations of fatigue between the dif-ferent conditions. Regarding the muscle excitation metrics, although the mean amplitude, peak value and area under the curve remained unchanged across conditions, a significant reduction in the trend coefficient, indicating motor unit recruitment over time, was observed with both music (BB: -10.39%, p < 0.001; BR: -9.40%, p < 0.001) and verbal encouragement (BB: -7.61%, p < 0.001; BR: -6.51%, p < 0.001) compared to the standard condition. For the trained participants, no significant differences were observed between conditions in terms of task duration and outcome measures related to muscle excitation and myoelectric manifestations of fatigue, suggesting the possible presence of a ceiling effect on motivation. These results highlight the significant role of external motivational stimuli, such as music and verbal encouragement, in improving task performance in untrained subjects, probably through more ef-fective and efficient recruitment of motor units.

The development of sarcopenia in the elderly is associated to many potential factors and/or processes, that impair the renovation and the maintenance of skeletal muscle mass and strength as ageing progresses. Among them, a defect by skeletal muscle to respond to anabolic stimuli is to be considered. Common anabolic stimuli/signals in skeletal muscle are hormones (insulin, growth hormones, IGF-1, androgens, β-agonists such epinephrine), substrates (amino acids as protein precursors on top, but also glucose and fat, as source of energy), metabolites (such as β-agonists and HMB), some cytokines, various biochemical/ intracellular mediators), physical exercise, neurogenic and immune-modulating factors, etc. Each of them may exhibit a reduced effect upon skeletal muscle as ageing progresses. In this review article, we will concisely overview the effects of anabolic signals on muscle metabolism, as well as currently available evidence of a resistance, at skeletal muscle level, to any of the above-mentioned anabolic factors, from both in vitro and in vivo studies.

Background: The maximal one-repetition test (1-RM) is widely used in scientific research; however, there are conflict results regarding its reproducibility in elderly population. The present study aimed to analyze the reproducibility the test both before and after a 12 week training period by using the bench press and leg press 45° 1-RM tests in the elderly taking into consideration the training experience and strength level of the women. Methods: Elderly women (n = 376; age, 68.5 ± 14.1 years; height, 162.7 ± 5.5 cm; body mass, 71.2 ± 16.0 kg) who underwent ≥3 months of resistance training performed an initial week of familiarization and a second week of testing and retest, with a 48–72 hour interval. Results: The results showed maximal and relative load strength of 39.3 kg and 0.59 kg/body mass for lower limbs and 20.9 kg and 0.31 kg/body mass for upper limbs. The Kappa indices were 0.93 and 0.95, and the intraclass correlation coefficients were 0.99 and 0.99 for the lower and upper limbs, respectively. Conclusion: Therefore, the present study confirms that the 1-RM test has high reliability and reproducibility in the elderly, for both upper and lower limbs.

Evidence suggests that COVID-19 infection can cause lasting health consequences. Multidiscipli-nary rehabilitation services have been recommended to reduce the sequalae. However, the effec-tiveness of physical exercise interventions remains insufficiently documented. The aim of this study was to develop and implement a specific and well tolerated protocol-based, intervention to reduce muscle weakness in older adults impacted by COVID-19. Forty six older adults random-ized into Intervention and Control Groups. Isometric and isokinetic strength assessments were conducted for selected muscle groups using JBA Staniak® torquemeter and Biodex System 3 dy-namometer. Functional abilities were evaluated with the Time Up and Go test and Chair Stand Tests. Men in intervention group demonstrated a significant improvement in static conditions for knee flexors (KF), trunk extensors (TE) and trunk flexors (TF) and in dynamic conditions for knee extensors (KE). Women in intervention group showed significant improvement in static condition for EF, KF, TE and TF and in dynamic for a KE and for a KF. The interaction GROUP x TESTING SESSION was significant for Chair test (s) and Chair test (n). Our results demonstrate the effec-tiveness of a well-tolerated, protocol-based approach that can be used to diminish long lasting functional deficits in post-covid survivors.

Background: The effects of gait training based on the positioning of affected foot muscle activity, gait parameters, and balance ability were investigated in patients with subacute stroke. Material and Methods: Forty-five patients with subacute stroke were randomly assigned to three groups: straight gait training (SGT) group (n = 15), outward curved gait training group with the paretic foot positioned laterally (n = 15), or inward curved gait training (ICGT) group with the paretic foot positioned medially (n = 15). All groups received 30-minute interventions, comprising 15 min of gait training, five times per week for four weeks. Outcomes were measured in terms of muscle activation of the gluteus maximus (GM), vastus medialis, and vastus lateralis; five gait parameters (step length, stance phase, swing phase, velocity, and maximum force); and balance ability assessed using the timed up and go (TUG) test. Results: All groups exhibited significant improvements in all variables after the 4-week intervention period (p &lt; 0.05). However, except for comparisons between the SGT and ICGT groups in terms of GM muscle activity and TUG, no significant differences were observed between the groups for the other variables (p &gt; 0.05). Conclusions: Although patients with subacute stroke can improve their overall physical function regardless of the gait training method, ICGT may be more effective in enhancing muscle activity and balance ability.

Duchenne muscular dystrophy (DMD) is caused by genetic mutations in the cytoskeletal-sarcolemmal anchor protein dystrophin. Repeated cycles of sarcolemmal tearing and repair lead to a variety of secondary cellular and physiological stressors that are thought to contribute to weakness, atrophy, and fibrosis. Collectively, these stressors can contribute to a pro-inflammatory milieu in locomotor, cardiac, and respiratory muscles. Given the many unwanted side effects that accompany current anti-inflammatory steroid-based approaches for treating DMD (e.g., glucocorticoids), there is a need to develop new therapies that address inflammation and other cellular dysfunctions. Adiponectin receptor (AdipoR) agonists, which stimulate AdipoR1 and R2 isoforms on various cell types, have emerged as therapeutic candidates for DMD due to their anti-inflammatory, anti-fibrotic, and pro-myogenic properties in pre-clinical human and rodent DMD models. Although these molecules represent a new direction for therapeutic intervention, the mechanisms through which they elicit their beneficial effects are not yet fully understood, and DMD-specific data is limited. The overarching goal of this review is to investigate how adiponectin signaling may ameliorate pathology associated with dystrophin deficiency through inflammatory-dependent and -independent mechanisms, and to determine if current data supports their future progression to clinical trials.

Muscle mass, strength and physical function are known to decline with age. This is associated with the development of geriatric syndromes including sarcopenia and frailty. These conditions are associated with disability, falls, longer hospital stay, higher readmission rates, institutionalisation, osteoporosis, and death. Moreover, they are associated with reduced quality of life, as well as substantial costs to health services around the world. Dietary protein is essential for skeletal muscle function. Older adults have shown evidence of anabolic resistance, where greater amounts of protein are required to stimulate muscle protein synthesis and therefore require higher daily amounts of dietary protein. Research shows that resistance exercise has the most beneficial effect on preserving skeletal muscle. A synergistic effect has been noted when this is combined with dietary protein, yet studies in this area lack consistency. This is due, in part, to the variation that exists within dietary protein, in terms of dose, quality, source, amino acid composition and timing. Research has targeted participants that are replete in dietary protein with negative results. Inconsistent measures of muscle mass, muscle function, physical activity and diet are used. This review attempts to summarise these issues, as well as introduce the possible role of the gut microbiome and its metabolome in this area.

This randomized trial compared pea protein, whey protein, and water-only supplementation on muscle damage, inflammation, delayed onset of muscle soreness (DOMS), and physical fitness test performance during a 5-day period after a 90-minute eccentric exercise bout in non-athletic, non-obese males (n=92, ages 18-55 years). The two protein sources (0.9 g protein/kg divided into three doses/day) were administered under double blind procedures. The eccentric exercise protocol induced significant muscle damage and soreness, and reduced bench press and 30-second Wingate performance. Whey protein supplementation significantly attenuated post-exercise blood levels for biomarkers of muscle damage compared to water-only, with large effect sizes for creatine kinase and myoglobin during the 4th and 5th days of recovery (Cohen's d &gt;0.80); pea protein versus water supplementation had an intermediate, non-significant effect (Cohen's d &lt;0.50); and no significant differences between whey and pea protein were found. Whey and pea protein compared to water supplementation had no significant effects on post-exercise DOMS and the fitness tests. In conclusion, high intake of whey protein for 5 days after intensive eccentric exercise mitigated efflux of muscle damage biomarkers, with intake of pea protein having an intermediate effect in part due to the 24% lower leucine amino acid content.

Background. Sarcopenia, defined as the loss of skeletal muscle mass and function, is a major clinical problem in many chronic illnesses, in cancer and in the elderly. Exercise and adequate nutrition, peculiarly dependents on availability of essential amino acids, considered the primary strategies for prevention and treatment of protein synthetic deficits, affect both the efficient scavenging of aged and overused protein molecules and the renewal, by maintaining muscular protein synthesis. Many questions still remain about the regulation of protein syntheses and degradation. Degradation of inefficient proteins or organelles is performed by the sum of micro and macro-autophagy plus ubiquitin-proteasome system, activities known as proteostasis, necessary to preserve and promote protein masses and consequently, the body’s reserves. However, how protein synthesis is regulated, and how activation of the mTOR complex may modulate and transduce the flow of information provided by exercise and nutrition to balance proteostasis and syntheses, is far from being fully understood. We suggest that energy production and availability, thus also mitochondria, may have a pivotal role in synchronizing activity and functional outcomes of protein syntheses, and that those syntheses, since higly energy demanding, are main effectors of AMPK dependent autophagy activation by consuming ATP and producing AMP. Conclusion. While in normal conditions protein syntheses drive autophagy activation by decreasing ATP to AMP ratio, conversely autophagy may be inefficiently activated when chronic both low production and consumption of ATP would result in lowest concentrations of AMP, and therefore both blunted rates of protein syntheses and autophagy would be observed. We suggest that this functional hypothesis may explain sarcopenia in many pathological conditions , as in cancer or in aging muscles.

In several mammalian species including humans, complex stimulation patterns such as cognitive challenge and physical exercise lead to improvements in organ function, organism health and performance, as well as possibly longer lifespans. The hypothesis is presented here that activity-dependent transcriptional programs, induced by these environmental stimuli, temporarily and lightly de-differentiate somatic cells such as neurons and muscle cells into a state that resembles functionally younger cells to allow cellular remodeling and adaptation of the organism to environmental change. This cellular adaptation program targets several process classes that are heavily implicated in aging, such as mitochondrial metabolism, cell-cell communication, intracellular signaling and epigenetic information processing and leads to functional improvements in these areas. I reverse engineer these activity-dependent gene programs, identify critical molecular nexus points such as CREB, MEF2 and cFos and speculate as to how one might leverage them to prevent and attenuate human aging-related decline of body function, enhance human performance and restore more youthful levels of function and morphology. The findings presented here can serve as a basis for the study and development of effective longevity efforts as the underlying gene programs could be used as markers for treatment success and as targets for therapy development.

Alzheimer’s Disease (AD) is a debilitating neurodegenerative disease characterized by the accumulation of extracellular amyloid-β peptides (Aβ) within the cerebral parenchyma and vasculature, the latter termed cerebral amyloid angiopathy (CAA). This study utilized confocal imaging to investigate heparan sulfate (HS) within the cerebrovasculature and its potential associations with CAA, gender, and ApoE4 genotype. Our investigation revealed elevated levels of HS in the cerebrovasculature of AD patients with severe CAA. Additionally, these patients exhibited higher colocalization of HS with Aβ in the cerebrovasculature, including both endothelial and vascular smooth muscle cell compartments. Intriguingly, a reversal in the polarized expression of HS within the cerebral vasculature was detected in AD patients with severe CAA, suggesting a potential role in CAA development. Furthermore, male patients exhibited lower levels of both parenchymal and cerebrovascular HS. Additionally, ApoE4 carriers displayed heightened cerebrovascular Aβ expression and a tendency of elevated cerebrovascular HS levels in AD patients with severe CAA. Overall, these findings shed light on the intricate interplay between HS, Aβ, ApoE, and vascular pathology in AD, underscoring the potential roles of cerebrovascular HS in CAA development and AD pathology. Further exploring the underlying mechanisms may present novel therapeutic avenues for AD treatment.

The hyperactivation of the sympathetic nervous system (SNS) is linked to obesity, hypertension, and type 2 diabetes, with elevated norepinephrine (NE) levels being a key feature. Previous research has shown increased sodium-glucose cotransporter 1 (SGLT1) protein in kidneys of hypertensive rodents, prompting investigation into SGLT1 expression in other tissues such as skeletal muscle. This study aimed to assess: i) whether skeletal muscle cells and tissue express SGLT1 and SGLT2 protein; ii) if NE increases SGLT1 in skeletal muscle cells and iii) whether skeletal muscle of neurogenically hypertensive mice exhibits increased SGLT1 expression. We found that i) skeletal muscle cells and tissue are a novel source of SGLT2 protein and ii) NE significantly elevated SGLT1 in skeletal muscle cells. As SGLT2 inhibition (SGLT2i) with Empagliflozin increased SGLT1, in vivo studies with the dual SGLT1/2i, Sotagliflozin were warranted. Treatment of neurogenically hypertensive mice with Sotagliflozin significantly reduced blood pressure. Our findings suggest that SNS activity upregulates the therapeutic target, SGLT1 in skeletal muscle, potentially worsening cardiometabolic control. As clinical trial data suggests cardiorenal benefits with SGLT2i, future studies should aim to utilize sole SGLT1i which may offer a therapeutic strategy for conditions with heightened SNS activity, such as hypertension, diabetes and obesity.

Oleuropein, glycosylated secoiridoid present in olive leaves is known to be an important antioxidant phenolic compound. We studied the antioxidant effect of low doses of oleuropein aglycone (3,4-DHPEA-EA) and oleuropein aglycone peracetylated (3,4-DHPEA-EA(P)) in murine C2C12 myocytes treated with hydrogen peroxide (H2O2). Both compounds were used at a concentration of 10 μM and were able to inhibit cell death induced by the H2O2 treatment, with 3,4-DHPEA-EA(P) being more. Under our experimental conditions, H2O2 efficiently induced the phosphorylated-active form of JNK and of its downstream target c-Jun. We demonstrated, by Western blot analysis, that 3,4-DHPEA-EA(P) was efficient in inhibiting the phospho-active form of JNK. This data suggests that the growth arrest and cell death of C2C12 proceeds via the JNK/c-Jun pathway. Moreover, we demonstrated that 3,4-DHPEA-EA(P) affects the myogenesis of C2C12 cells; because MyoD mRNA levels and the differentiation process are restored with 3,4-DHPEA-EA(P) after treatment. Overall, the results indicate that 3,4-DHPEA-EA(P) prevents ROS-mediated degenerative process in a genomic and epigenomic manner by functioning as an efficient antioxidant.

Oleuropein, glycosylated secoiridoid present in olive leaves is known to be an important antioxidant phenolic compound. We studied the antioxidant effect of low doses of oleuropein aglycone (3,4-DHPEA-EA) and oleuropein aglycone peracetylated (3,4-DHPEA-EA(P)) in murine C2C12 myocytes treated with hydrogen peroxide (H2O2). Both compounds were used at a concentration of 10 μM and were able to inhibit cell death induced by the H2O2 treatment, with 3,4-DHPEA-EA(P) being more. Under our experimental conditions, H2O2 efficiently induced the phosphorylated-active form of JNK and of its downstream target c-Jun. We demonstrated, by Western blot analysis, that 3,4-DHPEA-EA(P) was efficient in inhibiting the phospho-active form of JNK. This data suggests that the growth arrest and cell death of C2C12 proceeds via the JNK/c-Jun pathway. Moreover, we demonstrated that 3,4-DHPEA-EA(P) affects the myogenesis of C2C12 cells; because MyoD mRNA levels and the differentiation process are restored with 3,4-DHPEA-EA(P) after treatment. Overall, the results indicate that 3,4-DHPEA-EA(P) prevents ROS-mediated degenerative process in a genomic and epigenomic manner by functioning as an efficient antioxidant.

Aerobic exercise training (AET) has been used in the management of heart disease. AET may, totally or partially, restore the activity and/or expression of proteins that regulate calcium (Ca2+) handling, optimize intracellular Ca2+ flow, and attenuate cardiac functional impairment in failing hearts. However, the literature presents conflicting data regarding the effects of AET on Ca2+ transit and cardiac function in rats with heart failure resulting from aortic stenosis. The objective of this study was to evaluate the effects of AET on calcium handling and cardiac function in rats with heart failure due to aortic stenosis. Wistar rats were distributed into two groups: control (Sham; n= 61) and aortic stenosis (AoS; n= 44). After 18 weeks, the groups were redistributed into: non-exposed to exercise training (Sham, n = 28 and AoS, n = 22) and trained (Sham-ET, n = 33 and AoS-ET, n = 22) for 10 weeks. Treadmill exercise training was performed with a velocity equivalent to the lactate threshold. Echocardiogram, isolated papillary muscle, and isolated cardiomyocyte analyzed cardiac function. During isolated papillary muscle assay and isolated cardimyocyte was evaluated Ca2+. The expression of regulatory proteins of diastolic Ca2+ was analyzed via Western Blot. AET attenuated the diastolic dysfunction and benefited the systolic function. AoS-ET animals presented better response to post-rest contraction, and SERCA2a and L-type Ca2+ channels blocked than the AoS. Furthermore, AET was able to improve aspects of the mechanical function and the responsiveness of the myofilaments to the Ca2+ of the AoS-ET animals. AoS animals presented alteration in the protein expression of the SERCA2a and NCX, and AET restored SERCA2a and NCX levels near normal values. Therefore, AET increased SERCA2a activity, improved the cellular Ca2+ influx mechanism, and increased myofilament responsiveness to Ca2+, attenuating cardiac dysfunction at cellular, tissue, and chamber levels in animals with aortic stenosis and heart failure.

The proper regulation of RNA processing is critical for muscle development and the fine-tuning of contractile ability between muscle fiber-types. RNA binding proteins (RBPs) regulate the diverse steps in RNA processing including alternative splicing, which generates fiber-type specific isoforms of structural proteins that confer contractile sarcomeres with distinct biomechanical properties. Alternative splicing is disrupted in muscle diseases such as myotonic dystrophy and dilated cardiomyopathy, and is altered after intense exercise as well as with aging. It is therefore important to understand splicing and RBP function, but currently only a small fraction of the hundreds of annotated RBPs expressed in muscle have been characterized. Here we demonstrate the utility of Drosophila as a genetic model system to investigate basic developmental mechanisms of RBP function in myogenesis. We find that RBPs exhibit dynamic temporal and fiber-type specific expression patterns in mRNA-Seq data and display muscle-specific phenotypes. We performed knockdown with 105 RNAi hairpins targeting 35 RBPs and report associated lethality, flight, myofiber and sarcomere defects, including flight muscle phenotypes for Doa, Rm62, mub, mbl, sbr, and clu. Interestingly, knockdown phenotypes of spliceosome components, as highlighted by phenotypes for A-complex components SF1 and Hrb87F (hnRNPA1), revealed level- and temporal-dependent myofibril defects. We further show that splicing mediated by SF1 and Hrb87F is necessary for Z-disc stability and proper myofibril development, and strong knockdown of either gene results in impaired localization of Kettin to the Z-disc. Our results expand the number of RBPs with a described phenotype in muscle and underscore the diversity in myofibril and transcriptomic phenotypes associated with splicing defects. Drosophila is thus a useful model to gain disease-relevant insight into cellular and molecular phenotypes observed when expression levels of splicing factors, spliceosome components and splicing dynamics are altered.

Targets for finished livestock are often determined by expected fat, either subcutaneous or intramuscular. These targets are used frequently to improve the chances of acceptable eating quality. Lower intramuscular fat, lack of product uniformity, and reduced or insufficient tenderness can negatively impact beef acceptability. This study aimed to investigate differences in gene expression that potentially alter subsequent metabolism and intercellular signaling in the muscle and proximate intermuscular and subcutaneous adipose tissue in beef carcasses at different fat endpoints. In this study, Longissimus thoracis muscle samples and associated adipose tissue were collected at harvest. RNA was harvested from both tissues, and individual samples were sequenced using RNAseq. Differential expression was determined using edgeR, and p-values were adjusted using the Benjamini-Hochberg method. A corrected p-value of 0.005 and log₂ (fold change) of 1 was set as the threshold to identify differential expression of genes. Comparison between intermuscular fat and subcutaneous fat showed no differences between the genes activated in the two adipose tissue depots, suggesting that subcutaneous fat could be sampled to evaluate changes in adipose tissue. Carcass data allowed the classification of carcasses by projected USDA quality grades (marbling targets). In the comparison between muscle from Standard and Choice carcasses, 15 genes were downregulated, and 20 were upregulated. The insulin receptor substrate 1 (IRS 1) gene was the only known functionally important gene to be differentially expressed. There were 49 downregulated genes and 113 upregulated genes in the comparison between adipose tissue from Standard and Choice carcasses. These genes are mostly related to the metabolism of fat and energy. This potentially indicates that muscle is not changing at the transcript level as much as the adipose tissue at the sampled endpoints. Also, subcutaneous fat can be used to evaluate transcript changes in both subcutaneous and intermuscular fat. However, it is not clear if these fat tissues can be used as surrogates for intramuscular fat or marbling.

Oleuropein, glycosylated secoiridoid present in the olive leaves, is known as an important antioxidant phenolic compound. We studied the antioxidant effect of low dose of oleuropein aglycone (3,4-DHPEA-EA) and oleuropein aglycone peracetylated (3,4-DHPEA-EA(P)) in murine C2C12 myocytes treated with hydrogen peroxide (H2O2). Both compounds were used at a concentration of 10 μM and were able to inhibit cell death induced by H2O2 treatment, with 3,4-DHPEA-EA(P) being more. Under our experimental conditions H2O2 efficiently induced the phosphorylated-active form of JNK and of its downstream target c-Jun. We demonstrated, by Western blot analysis, that 3,4-DHPEA-EA(P) was efficient in inhibiting the phospho-active form of JNK. This data suggest that growth arrest and cell dead of C2C12 proceeds via the JNK/c-Jun pathway. Moreover, we demonstrated that 3,4-DHPEA-EA(P) affects myogenesis of C2C12 cells; because the MyoD mRNA levels and the differentiation process are restored after treatment with 3,4-DHPEA-EA(P). Overall, the results indicate that 3,4-DHPEA-EA(P) prevents ROS-mediated degenerative process by functioning as an efficient antioxidant.

Low efficiency of in vivo transfection of a few fibers revealed a novel tissue network which temporally amplified growth stimulation in the entire regenerating rat soleus muscle. This acupuncture-like effect was demonstrated when the fibers began to grow after complete fiber degradation, synchronous inflammation, myoblast and myotube formation. The first detection of neonatal sarcoplasmic/endoplasmic reticulum ATPase (SERCA1b) has been made in this system. The neonatal, fast and slow SERCA isoforms displayed consequent change with innervation and differentiation, recapitulating events in muscle development. In vivo transfection of myotubes with plasmids expressing dominant negative Ras or a calcineurin inhibitor peptide (Cain/cabin) proved that the expression of the slow myosin heavy chain and the slow muscle type SERCA2a are dif-ferently regulated. In vivo transfection of a few nuclei of myotubes with dnRas or SER-CA1b shRNA stimulated fiber size growth in the whole regenerating muscle but only until the full size had been reached. Growth stimulation by Ras and SERCA1b antisense was abolished in co-transfection with Cain or in case of perimuscular injection with IL4 antibody. This revealed a novel signalling network resembling to scale-free networks which, starting from transfected fiber myonuclei as “hubs”, can amplify growth stimula-tion uniformly in the entire regenerating muscle.

Arjunolic acid (AA) is a triterpenoid saponin majorly found in the Terminalia arjuna and is claimed to exert the cardiovascular protective effects as a phytomedicine. However, it is unclear how AA exerts the effects at the molecular level. Hence, this study used an in vitro model using lipopolysaccharide (LPS)-stimulated H9C2 and C2C12 myotubes to investigate the cardioprotective effects of arjunolic acid (AA) via MyD88-dependant TLR4 downstream signaling markers expression. The myotubes were developed by differentiating rat H9C2 and mouse C2C12 myoblast cells. The MTT viability assay was used to assess the cytotoxicity of AA. LPS induced in vitro cardiovascular disease model was developed in H9C2 and C2C12 myotubes. The treatment groups were designed such as control (untreated), LPS control, positive control (LPS+ pyrrolidine dithiocarbamate (PDTC)-25 µM), and treatment groups were co-treated with LPS and three doses of AA (50, 75, and 100 µM). The changes in the expression of TLR4 downstream signaling markers were evaluated through High Content Screening (HCS) and Western Blot (WB) analysis. The outcomes demonstrated that the expression of MyD88, MAPK, JNK, and NFκB markers were significantly upregulated in the LPS-treated groups compared to the untreated control. Evidently, the HCS analysis revealed that MyD88, NF-κB, p38, and JNK were significantly downregulated in the H9C2 myotube in the AA treated groups (50, 75, and 100 µM). For, the C2C12 myotube, the expression of NFκB was downregulated. TLR4 marker expression in H9C2 and C2C12 myotubes was subsequently decreased by AA treatment, suggesting possible cardioprotective effects of AA.

Branched-chain amino acid (BCAA) levels are associated with skeletal muscle cross-sectional area (CSA). Serum BCAA levels are enhanced by whey protein supplementation (WPS), and evidence in clinical populations suggests an association of single nucleotide polymorphisms (SNPs) with BCAA metabolite levels. It is not known whether the same SNPs are associated with the ability to catabolise BCAAs from exogenous sources, such as WPS. The present study investigated whether possessing a higher number of alleles associated with increased BCAA metabolites correlates with muscle fiber CSA of m. vastus lateralis in physically active participants, and whether any relationship is enhanced by WPS. Endurance-trained participants (n=75) were grouped by self-reported habitual WPS consumption and genotyped for 5 SNPs (PPM1K rss1440580, APOA5 rs2072560, CBLN1 rs1420601, DDX19B rs12325419, TRMT61A rs58101275). Body mass, BMI and fat percentage were significantly lower and muscle mass higher in the WPS group (n=22) compared to Non-WPS (n=53). The number of BCAA-increasing alleles was correlated with fiber CSA in the WPS group (r=0.75, p&lt;0.0001) and was stronger for fast-twitch fibers (p=0.001) than slow-twitch fibers (p=0.048). Similar results remained when corrected for multiple covariates (age, physical activity, meat and dairy intake). No correlation was found in the Non-WPS group. This study presents novel evidence of a positive relationship between BCAA-increasing alleles and muscle fiber CSA in athletes habitually consuming WPS. We suggest that a high number of BCAA-increasing alleles improves the efficiency of WPS by stimulation of muscle protein synthesis, and contributes to greater fiber CSA.

We investigated effects of molecular hydrogen (H2) supplementation on acid-base status, pulmonary gas exchange responses, and local muscle oxygenation during incremental exercise. Eighteen healthy, trained subjects in a randomized, double-blind, crossover design received H2-rich calcium powder (HCP) (1500 mg/day, containing 2.544 µg/day of H2) or H2-depleted placebo (1500 mg/day) for 3 consecutive days. They performed cycling incremental exercise starting at 20-watts work rate, increasing by 20 watts/2 min until exhaustion. Breath-by-breath pulmonary ventilation (VE) and CO2 output (VCO2) were measured and muscle deoxygenation (deoxy[Hb + Mb]) was determined via time-resolved-NIRS in the vastus lateralis (VL) and rectus femoris (RF). Blood gases' pH, lactate, and HCO3− concentrations were measured at rest and 120-, 200-, and 240-watt work rates. At rest, the HCP group had significantly lower VE, VCO2, and higher HCO3−, PCO2 versus placebo. During exercise, a significant pH decrease and greater HCO3− continued until 240-watts work rate in HCP. The VE was significantly lower in HCP versus placebo, but HCP did not affect the gas exchange status of VCO2 or oxygen uptake (VO2). HCP increased absolute values of deoxy[Hb + Mb] at the RF but not VL. Thus, HCP-induced hypoventilation would lead to lower pH and secondarily impaired balance between O2 delivery and utilization in the local RF during exercise, suggesting that HCP supplementation, which increases the at-rest antioxidant potential, affects the lower ventilation and pH status during incremental exercise. HPC induced a significantly lower O2 delivery/utilization ratio in the RF but not the VL, which may be because these regions possess inherently different vascular/metabolic control properties, perhaps related to fiber-type composition.

Recently, selection in pigs has been focused on improving the lean meat content in carcasses; this focus has been most evident in breeds constituting a paternal component in breeding. Such sire-breeds are used to improve the meat quantity of cross-breed pig lines. However, even in one breed, a significant variation in the meatiness level can be observed. In the present study, the comprehensive analysis of genes and microRNA expression profiles in porcine muscle tissue was applied to identify the genetic background of meat content. The comparison was performed between whole gene expression and miRNA profiles of muscle tissue collected from two sire-line pig breeds (Piertain, Hampshire). The RNA-seq approach allowed the identification of 627 and 416 differentially expressed genes (DEGs) between pig groups differing in terms of loin weight between Pietrain and Hampshire breeds, respectively. The comparison of miRNA profiles showed differential expression of 57 microRNAs for Hampshire and 34 miRNAs for Pietrain pigs. Next, 43 genes and 18 miRNAs were selected as differentially expressed in both breeds and potentially related to muscle development. According to Gene Ontology analysis, identified DEGs and microRNAs were involved in the regulation of the cell cycle, fatty acid biosynthesis and regulation of the actin cytoskeleton. The most deregulated pathways dependent on muscle mass were the Hippo signalling pathway connected with the TGF-beta signalling pathway and controlling organ size via the regulation of ubiquitin-mediated proteolysis, cell proliferation and apoptosis. The identified target genes were also involved in pathways such as the FoxO signalling pathway, signalling pathways regulating pluripotency of stem cells and the PI3K-Akt signalling pathway. The obtained results indicate molecular mechanisms controlling porcine muscle growth and development. Identified genes (SOX2, SIRT1, KLF4, PAX6 and genes belonging to the transforming growth factor beta superfamily) could be considered candidate genes for determining muscle mass in pigs.

Calcium (Ca2+) ions act as second messenger, regulating several cell functions. Mitochondria are critical organelles for the regulation of intracellular Ca2+. Mitochondrial calcium (mtCa2+) uptake is ensured by the presence in the inner mitochondrial membrane (IMM) of the mitochondrial calcium uniporter (MCU) complex, a macromolecular structure composed of pore-forming and regulatory subunits. MtCa2+ uptake plays a crucial role in the regulation of oxidative metabolism and cell death. Many evidences demonstrate that dysregulation of mtCa2+ homeostasis can have serious pathological outcomes. In this review, we briefly discuss the molecular structure and the function of the MCU complex and then we focus our attention on human diseases in which a dysfunction in mtCa2+ has been showed.

The dietary proteins are one of the most important factors determining health conditions in human. The sufficient digestion and absorption of dietary proteins in the digestive tract have positive effects on performance and recovery in sportspeople or athletes. Improving of protein digestibility is a strategy for maintaining health status and optimal performance in sport or exercise activities. The hypothesis of the present study is that Weizmannia coagulans BC 99 (BC99) can increase muscle mass and strength. This randomized double-blind, controlled trial assigned 72 male college students to receive probiotics (n = 36, 20.25±1.03 years; 1.79±5.94 cm; 73.55±8.73 kg, protein powder with BC99) or placebo (n = 36, 20.19±0.79 years; 179.25±5.16 cm; 73.61±8.24 kg, protein powder) for 12-week. At the baseline and final stages of the study, strength tests and body composition assessment were performed; Blood and stool samples were taken at the end of the 12-week intervention, digestive enzymatic activity of stool samples, biochemical parameters, amino acids and hormone level of plasma were analyzed. BC99 administration significantly improved strength performance, skeletal muscle mass, activity of pepsin and trypsin, the concentrations of branched chain amino acids and essential amino acids, reduced activities of creatine kinase and lactic dehydrogenase and urea nitrogen (BUN) level, and increased testosterone and glucagon-like peptide-1 level in male college students. Therefore, BC99 supplementation can be an important nutritional strategy to improve strength performance, body composition, protein digestion and body metabolism in various groups of individuals.

Maximal athletic performance can be limited by various factors, including restricted respiratory function. These limitations can be mitigated through targeted respiratory muscle training, as supported by numerous studies. However, the full potential of respiratory training in competitive finswimming has not been fully investigated. This case study aims to evaluate performance variability during underwater phases in an elite Bi-Fins swimmer (current world record holder and multiple world championship medallist) over a 200m race simulation after an eight-week respiratory training using Airofit PRO™. Performance variability was assessed based on pre-test, inter-test, and post-test data. Each measurement included pulmonary function, body composition, and swim performance evaluations. The swimmer followed a 28-day training program with the AiroFit PRO™ respiratory trainer between tests. Significant improvements were observed in Wilcoxon paired-sample test between the pre-test and post-test in underwater distance (p=0.012; d=1.26), underwater time (p=0.012; d=1.26), and number of underwater kicks (p=0.043; d=1.01), resulting in a 14.23% longer underwater distance, 14.08% longer underwater time, and 14.94% increase in underwater kicks. Despite increased distance and time, underwater velocity remained stable, indicating improved underwater performance efficiency. The results suggest that the AiroFit PRO™ respiratory trainer has practical applications in finswimming training programs.

Introduction. Congenital muscular torticollis (CMT) is an asymmetrical head positioning resulting from structural changes in the sternocleidomastoid muscle (SCM) that occurs early in a child’s development period or due to perinatal trauma. Children with CMT exhibit a marked imbalance in tension between the SCMs. When the clinical picture is typical, an ultrasound scan is performed to reveal characteristic lesions, such as tissue fibrosis or post-traumatic changes. Early diagnosis of CMT in newborns and implementation of treatment offer the chance of a complete cure. Torticollis treatment aims to rebuild the SCM's normal function by restoring its anatomical length, normal cervical spine mobility and muscle flexibility to enable regular head movements. Surgical treatment is performed when conservative methods fail to improve the patient’s condition. Indications for surgery include marked shortening of the SCM, persistent fibrosis in the muscle, constant head and facial asymmetry, and rotation or lateral flexion in the cervical spine restricted by > 15°. After hip dislocations and foot deformities, pediatric orthopedics addresses torticollis as the third most common congenital anomaly. Aim. This study was a retrospective analysis of 111 children diagnosed and treated due to CMT. Methods. The following were determined: the relationship between the side of CMT location and the type of delivery (cc vs. natural), between the body weight at birth and the side of CMT location, between the extent of SCM thickening and the type of delivery, and the incidence of CMT depending on the order of delivery. Results and conclusions. The analysis showed that CMT was more common in boys 61(54%) than in girls 51(46%), which may be related to the greater birth weight in boys. Of the pediatric patients with CMT, 76% were primiparous. More often, children born via natural delivery had left-sided torticollis with a more significant broadening of the SCM on ultrasound scans than right-sided torticollis. Theories of torticollis development pathophysiology should be deepened, systematized, and further researched.

The investigation by the integrated approach newly introduced for this study indicates that insulin resistance (IR) would develop first preferentially in the muscle tissue with a relatively low cell turnover and then progress in sequence to the subcutaneous adipose tissue, to the visceral adipose tissue, and to the liver with higher cell turnovers. Moreover, metabolic disruptions due to IR vary widely from tissue to tissue, contrary to the conventional notion that IR merely impairs glucose uptake in the whole body. This warrants that IR be divided better into four distinct tissue specific IRs: muscle insulin resistance (MIR), subcutaneous adipose insulin resistance (s-AIR), visceral adipose insulin resistance (v-AIR), and hepatic insulin resistance (HIR). Tissue-specific IRs developing in the order of MIR, s-AIR, v-AIR, and HIR – producing tissue specific metabolic disruptions – would amount to nothing but the whole body insulin resistance (WBIR) evolving in four distinctively insulin resistant stages. The four stage metabolic evolution from rapid weight gain to visceral obesity to rapid weight loss to full blown diabetes not only complies well with the natural development history of diabetes but also resolves most of the controversies regarding obesity or diabetes, including visceral obesity, obesity paradox, and dawn phenomenon that have long remained metabolic puzzles. In addition, the four-stage WBIR evolution model refutes the entrenched notion of the lipid-induced insulin resistance (LIIR) but supports instead the glycation-induced insulin resistance (GIIR) proposed in this study. A speculation is that the glycation reaction activated ever more with WBIR evolving may serve as the common thread connecting each other a cluster of disorders or diseases that are often collectively referred to as the metabolic syndrome, such as obesity, diabetes, cardio/cerebral vasculopathy, nephropathy, neuropathy, and retinopathy.

Instep weights cause mechanical changes, modifying muscle activity and changing ground plantar support. 30 semi-professional sprinters, randomized in 3 groups [no-weight, Ascending (50, 100, 150 and 200g), Descending (200, 150, 100 and 50g)] run 6 consecutive 50-meter series at maximum speed (first and sixth without weights); partial, total times and speed were analyzed. Instep weights were safe and well tolerated. 6th series speed decreased except in men’s ascending group, who achieved a lower time in sixth compared to first series. Weights presented in ascending order in men during warm-up could improve running time. Instep weights neuromuscular effects could compensate men’s tiredness in last series; weights could be included in training methodologies. Men training weights presented in ascending order may provide better results.

Currently, there is an increase in the aging of the population, which represents a risk factor for many diseases, including sarcopenia. Sarcopenia involves progressive loss of mass, strength, and function of the skeletal muscle. Some mechanisms include alterations in muscle structure, reduced regenerative capacity, oxidative stress, mitochondrial dysfunction, and inflammation. The zebrafish has emerged as a new model for studying skeletal muscle aging because of its numerous advantages, including histological and molecular similarity to human skeletal muscle. In this study, we used fish of 2, 10, 30, and 60 months of age. The older fish showed a higher frailty index because of reduced locomotor activity and alterations in biometric measurements. We observed changes in muscle structure with a decreased number of myocytes and an increase in collagen with aging, corresponding to alterations in the synthesis, degradation, and differentiation pathways. These changes were accompanied by mitochondrial alterations, such as a decrease in intermyofibrillar mitochondria, increased mitochondrial damage, and reduced mitochondrial dynamics. Overall, we demonstrated a similarity in the aging processes of muscle aging between zebrafish and mammals.

Brown-marbled grouper is one of the most important mariculture species in China, which is used as an important crossbreeding parent in grouper industry. Enhancing growth rates is a key target in fish breeding, and gaining insight into the underlying mechanisms responsible for growth differences among individuals can aid in the improvement of grouper growth rates. However, the mechanism behind this difference in growth in this fish is unclear. The difference of transcriptome profiles of muscle tissue between fast- and slow-growing brown-marbled grouper was analyzed by RNA-Seq. 77 significantly up-regulated genes and 92 significantly down-regulated genes were identified in the growth extreme groups. The up-regulated of ghr and tnni2 and the down-regulated of stc2 led to the growth advantages of brown-marbled grouper. The differently expressed genes (DEGs) were used for GO and KEGG enrichment analysis. The results of GO enrichments indicated that the significantly upregulated genes in the fast-growing group were involved in protein folding, actin cytoskeleton, myosin complex, etc. The results of KEGG enrichments indicated that the significantly upregulated genes in the fast-growing group were involved in glycolysis/ gluconeogenesis, adipocytokine signaling pathway, MAPK signaling pathway, carbon metabolism, PI3K-Akt signaling pathway, etc. To analysis the difference gene sets between fast- and slow-growing group, the RNA-seq data were used by gene set enrichment analysis (GSEA). The results showed that the PI3K/AKT/mTOR pathway was up-regulated in the fast-growing group. The up-regulated of this pathway could lead to higher nutrient absorption efficiency and lead to muscle growth in the fast-growing group. These results contribute to understanding of the molecular mechanisms of fast growth and regulative pathways regulating growth in brown-marbled grouper.

Amyotrophic lateral sclerosis (ALS) is also called "motor neuron disease”. In this review, we propose that ALS is not just a neuromotor disorder, but begins as a disorder of P53-modulated skeletal muscle metabolism, leading to failures at the energy state of the cells, incorrect redox states, motor denervation, and a loss of muscle fibers. Motoneurons die as a consequence of the lack of muscular feedback, and the oligomeric TDP43 aggregates progressively and relentlessly lead to mistakes in peripheral immune self-tolerance sustained over time. An effective treatment has not been found for this devastating pathology, as for 152 years the target has not been accurately defined. Scientists and doctors should consider new knowledge regarding ALS and consider immunomodulatory therapies that, based on genetic analysis and symptoms, can be combined with compounds that regulate metabolism and promote the elimination of useless organelles and cells. What if ALS could be cured as a result of seeing motor neuron disease differently? This review aims to develop that goal and change the paradigm of our understanding of ALS.

Much has been learned about the interaction between myosin and actin through biochemistry, in vitro motility assays and cryo-electron microscopy of F-actin decorated with myosin heads. Comparatively less is known about actin-myosin interactions within the filament lattice of muscle, where myosin heads function as independent force generators and thus most measurements report an average signal from multiple biochemical and mechanical states. All of the 3-D imaging by electron microscopy that has revealed the interplay of the regular array of actin subunits and myosin heads within the filament lattice has been accomplished using the flight muscle of the large waterbug Lethocerus sp. Lethocerus flight muscle possesses a particularly favorable filament arrangement that enables all the myosin cross-bridges contacting the actin filament to be visualized in a thin section. This review covers the history of this effort and the progress toward visualizing the complex set of conformational changes that myosin heads make when binding to actin in several static states as well as fast frozen actively contracting muscle. The efforts have revealed a consistent pattern of changes to the myosin head structures determined by X-ray crystallography needed to explain the structure of the different acto-myosin interactions observed in situ.

We explored the hypothesis that progesterone direct effect on Trichinella spiralis might be mediated indeed by a new steroid-binding parasite protein. Our first results showed that Progesterone decreases the parasite molting rate. We amplify, isolated, cloned and sequenced the PGRMC2 sequence using specific primers from known species. Furthermore, we expressed the protein and developed an antibody to performance immunofluorescent confocal microscopy, where detected that parasite cells showed expression of a P4-binding protein exclusively located at the oocyte and the parasite´s cuticle. Presence of the PGRMC2 protein in these cells was also confirmed by western blot and flow cytometry. Molecular modeling studies accompanied by computer docking using the sequenced protein showed that PGRMC2 is potentially able to bind steroid hormones such as progesterone, estradiol, testosterone, and dihydrodrotestosterone with different affinities. Phylogenetic analysis and sequence alignment clearly demonstrated that Trichinella spiralis PGRMC2 is related to a steroid-binding protein of another platyhelminths. Progesterone may probably act upon Trichinella spiralis oocytes probably by binding to PGRMC2. This research has implications in the field of host-parasite co-evolution as well as the sex-associated susceptibility to this infection. In a more practical matter, present results may contribute to the molecular design of new drugs with anti-parasite actions.

This study analyzes the efficacy of trapezius muscle electromyography (EMG) in discerning mental states, namely stress and meditation. Fifteen healthy participants were monitored to assess their physiological responses to mental stressors and meditation. Sensors were affixed to both the right and left trapezius muscles to capture EMG signals, while simultaneous electroencephalography (EEG) was conducted to validate cognitive states. Our analysis of various EMG features, considering frequency ranges and sensor positioning, revealed significant changes in trapezius muscle activity during stress and meditation. Notably, low-frequency EMG features facilitated enhanced stress detection. For accurate stress identification, sensor configurations can be limited to the right trapezius muscle. Furthermore, the introduction of a novel method for determining asymmetry in EMG features suggests that applying sensors on bilateral trapezius muscles can improve the detection of mental states. This research presents a promising avenue for efficient cognitive state monitoring through compact and convenient sensing.

Little is known about skeletal muscle thickness, echogenicity, and muscle quality (handgrip strength /muscle thickness) in breast cancer-related lymphedema (BCRL). Using B-mode ultrasound, we recorded the raw radiofrequency data of the affected (AA) and unaffected (UA) arms of women (n=20) with BCRL, and in 20 control women with no lymphedema (CA). The data were converted into images and measurements of skin, subcutaneous fat and muscle thickness were obtained. Within a designated region of interest, muscle echo-intensity was assessed using computer graded grey scale and muscle thickness was measured using ImageJ2. Handgrip strength was measured using standard dynamometry. We found that forearm muscle thickness was similar among AA, UA, and CA. When compared to the unaffected and control arms, the affected arm had a significantly higher (p 0.013) muscle echo-intensity. When compared to the AA, handgrip strength was similar to UA (p 0.401) but lower than CA (p 0.05). We conclude that the use of B-mode ultrasound is a reliable method to assess muscle thickness and EI in BCRL. When comparing AA to UA, the elevated levels of muscle EI in AA did not influence strength or muscle quality. The elevated EI in AA is a marker of abnormal health that needs to be further explored.

Gross strap muscle invasion (gSMI) in patients with differentiated thyroid cancer (DTC) was defined as high-risk recurrent group in the 2015 American Thyroid Association guidelines. However, controversy persists because several studies suggested gSMI had little effect on disease outcome. Herein, a systematic review and meta-analysis was conducted to investigate impact of gSMI on outcome of DTC. Methods: A systematic search of electronic databases (PubMed, EMBASE, Cochrane Library, and MEDLINE) for studies published until February 2020 was performed. Case-control studies and randomized controlled trials that studied the impact of gSMI on outcome of DTC were included. Results: Six studies (all retrospective studies) involving 13639 patients met final inclusion criteria. Compared with no extrathyroidal extension (ETE), patients with gSMI were associated with increased risk of recurrence (P=0.0004,OR, 1.46; 95% CI: 1.18 to 1.80) and lymph node metastasis (LNM) (P<0.00001,OR 4.19;95% CI. 2.53 to 6.96). For mortality (P=0.34,OR 1.47;95% CI:0.67 to 3.25), ten-year disease-specific survival (P=0.80, OR 0.91;95% CI:0.44 to 1.88) and distant metastasis (DM) (P=0.21, OR 2.94;95% CI. 0.54 to 15.93), there was no significant difference between gSMI and no ETE group. In contrast with maximal ETE, patients with gSMI were associated with decreased risk of recurrence (P<0.0001,OR, 0.58; 95% CI: 0.44 to 0.76) , mortality (P=0.0003,OR 0.20;95% CI:0.08 to 0.48), LNM (P=0.0003,OR 0.64;95% CI. 0.50 to 0.81) and DM (P=0.0009,OR 0.28;95% CI. 0.13 to 0.59). Conclusions: DTC patients with gSMI had a higher risk of recurrence and LNM than those without ETE. However, in contrast with maximal ETE, a much better prognosis was observed in DTC patients with only gSMI. The findings of our meta-analysis provide supportive evidence for the validity of the T category changes in the 8th edition American Joint Committee on Cancer system. The actual impact of gSMI should be re-evaluated and revised in the recurrent risk stratification system in the future.

Matrix metalloproteinases have been implicated in muscular dystrophy progression and recent studies described the role of MMP-10 in skeletal muscle pathology of young dystrophic mice. Nevertheless, its implication in dystrophin deficient hearts is still missing. Here, we aimed at investigating MMP-10 implication in severe muscular dystrophic progression and characterize MMP-10 loss in skeletal and cardiac muscles of aged dystrophic mice. We examined the histopathological effect of MMP-10 ablation in aged mdx mice, both in the hind limb muscles and heart tissues. We have found that MMP-10 loss compromises survival rates of aged mdx mice, with skeletal and cardiac muscles developing a chronic inflammatory response. Our findings indicate that MMP-10 is implicated in severe muscular dystrophy progression, identifying a new area of investigation that could lead to future therapies for dystrophic muscles.

The purpose of the present study was to examine the relationships between bat swing speed (BSS) and muscle thickness and lateral asymmetry of the trunk and limbs in collegiate baseball players. Twenty-four collegiate baseball players participated in this study. The maximum BSS in hitting a teed ball was measured using a motion capture system. The muscle thicknesses of the trunk (upper abdominal rectus, central abdominal rectus, lower abdominal rectus, abdominal wall, and multifidus lumborum), upper limb, and lower limb were measured using a B-mode ultrasonography. Lateral asymmetry between each pair of muscles was determined as the ratio of the thickness of the dominant side to that of the non-dominant side. Significant positive correlations were observed between BSS and muscle thicknesses of the abdominal wall and multifidus lumborum on the dominant side (r = 0.426 and 0.431, respectively; p < 0.05), while nearly significant positive correlations were observed between BSS and muscle thicknesses on the non-dominant side. No significant correlations were found between BSS and lateral asymmetry of all muscles. These findings indicate the importance of the trunk muscles for bat swing, and the lack of association between BSS and lateral asymmetry of muscle size.

This study aimed to investigate the effects of forearm postures and elbow joint angles on muscle torque and mechanomyography (MMG) signals. The torque about the elbow and MMG of the biceps brachii (BB) muscle were measured in 36 healthy subjects using an in-house elbow flexion testbed and Neuromuscular electrical stimulation (NMES) of the BB muscle. The BB muscle received stimulation intensity while the forearm was positioned in the neutral, pronation or supination. The elbow was flexed at angles 10°, 30°, 60° and 90°. (0° = full elbow extension). The study analyzed the impact of forearm posture(s) and elbow joint angle(s) on the root mean square value of torque (TQ_RMS). Subsequently, MMG parameters such as the root mean square value (MMG_RMS), the mean power frequency (MMG_MPF), and the median frequency (MMG_MDF), were analyzed in the longitudinal, lateral, and transverse axes of the BB muscle fibers. Forearm posture and elbow flexion angle were found to significantly influence TQ_RMS (P < 0.05). Similarly, MMG_RMS, MMG_MPF and MMG_MDF exhibited a significant difference for all postures and angles (P < 0.05). However, the combined main effect of forearm postures and elbow joint angles was insignificant in the longitudinal axis (P > 0.05). The study also found that MMG_RMS and TQ_RMS increased with the joint angle to 60° and decreased to the other angle(s). However, during this investigation,MMG_MPF and MMG_MDF exhibited a consistent decrease in response to joint angles. This finding suggests that the muscle contraction evoked by NMES may be influenced by the interplay between actin and myosin filaments, which are responsible for muscle contraction and are in turn influenced by muscle length. As restoring the function of limbs is a common goal in rehabilitation services, it becomes imperative to develop methods that may enable the real-time tracking of exact muscle dimensional changes and activation levels.

Background: Evaluating muscle mass and function among stroke patients is important. However, evaluating muscle volume and function is not easy due to the disturbance of consciousness and paresis. Temporal muscle thickness (TMT) has been introduced as a novel surrogate marker for muscle mass, function, and nutritional status. We herein performed a narrative literature review on temporal muscle and stroke to understand the current meaning of the TMT in the clinical stroke practice. Methods: The search was performed in PubMed, last updated in October 2021. Report on temporal muscle morphomics and stroke-related diseases or clinical entities were collected. Results: Four studies reported on TMT and subarachnoid hemorrhage, 2 intracerebral hemorrhage, 2 ischemic stroke, 2 standard TMT values, and 2 nutritional status. TMT was reported as a prognostic factor for several diseases, surrogate markers for skeletal muscle mass, and an indicator of nutritional status. Computed tomography, magnetic resonance imaging, and ultrasonography were used to measure TMT. Conclusions: TMT is gradually used as a prognostic factor of stroke or surrogate marker for skeletal muscle mass and nutritional status. Establishing standard methods to measure TMT and large prospective studies to investigate the further relationship between TMT and diseases are needed.

This study aims to explore the possibility of estimating a multitude of kinematic and dynamic quantities using subject-specific musculoskeletal models in real-time. The framework was designed to operate with marker-based and inertial measurement units enabling extensions far beyond dedicated motion capture laboratories. We present the technical details for calculating the kinematics, generalized forces, muscle forces, joint reaction loads, and predicting ground reaction wrenches during walking. Emphasis was given to reduce computational latency while maintaining accuracy as compared to the offline counterpart. Notably, we highlight the influence of adequate filtering and differentiation under noisy conditions and its importance for consequent dynamic calculations. Real-time estimates of the joint moments, muscle forces, and reaction loads closely resemble OpenSim's offline analyses. Model-based estimation of ground reaction wrenches demonstrates that even a small error can negatively affect other estimated quantities. An application of the developed system is demonstrated in the context of rehabilitation and gait retraining. We expect that such a system will find numerous applications in laboratory settings and outdoor conditions with the advent of predicting or sensing environment interactions. Therefore, we hope that this open-source framework will be a significant milestone for solving this grand challenge.

This study aimed to investigate the influence of cranio-cervical position on the electromyographical activity of the core muscles during the prone plank exercise. Twenty healthy participants were enrolled in this study. Muscle activation was registered using surface electromyography (sEMG) in the rectus abdominis (RA), external oblique (EO), internal oblique (IO) and lumbar portion of erector spinae (LES). Three prone plank conditions were randomly evaluated, varying the position of the cranio-cervical segment during the prone plank performance (NEUTRAL, FLEXION and EXTENSION). sEMG signals of each individual muscle, Total Intensity (TI) and ratings of perceived exertion (RPE) were analysed with statistical significance set at P&lt;0.05. FLEXION revealed significantly higher TI values compared to NEUTRAL and EXTENSION (p = 0.000; effect size (ES) &gt; 0.90). The RA presented larger activation in FLEXION compared to the other variations (p &lt; 0.05; ES &gt;0.70). FLEXION elicited a greater response compared to NEUTRAL for both sides of EO when compared to EXTENSION, and also for both sides of IO compared to the other conditions. Both FLEXION and EXTENSION reported higher RPE values compared to NEUTRAL. Cranio-cervical segment position influenced the electromyographical activation of core musculature, showing highest values when performing prone plank in a cranio-cervical flexion.

Cardiac myosin-binding protein C (MyBPC) is a thick-filament associated regulatory protein in the sarcomere. It regulates the sensitive contractile system of the myocardium by acting as a mechanical tether, sensitizing the thin filament or modulating myosin motor activity. Mutations in the MYBPC3 gene are a frequent cause for the development of hypertrophic cardiomyopathy, the most frequent cardiac disorder. Recently, the monoallelic double mutation MYBPC3Δ25bp/D389V has been discovered as a subset of the common MYBPC3Δ25bp variant in South Asia. MYBPC3Δ25bp/D389V carriers exhibit hyperdynamic features, which are considered an early finding for the development of hypertrophic cardiomyopathy. Using correlation-guided molecular dynamics simulations sampling, we show that the D389V mutation shifts the conformational distribution of the C2 domain of MyBPC. We further applied biochemical approaches to probe the effects of the D389V mutation on structure, thermostability and protein-protein interactions of MyBPC C2. The melting temperature (Tm) of MyBPC C2 D389V is decreased by 4 to 7 °C compared to wild type while the interaction of the C0-C2 domains with myosin and actin remains unchanged. Additionally, we utilized steered molecular dynamics (SMD) simulations to investigate the altered unfolding pathway of MyBPC C2 D389V. Based on our data, we propose a pathomechanism for the development of HCM in MYBPC3Δ25bp and MYBPC3Δ25bp/D389V carriers.

Sialyllactose (SL) is a functional human milk oligosaccharide essential for immune support, brain development, intestinal maturation, and antiviral defense. However, despite its established health benefits, the effect of SL on exercise performance and muscle mass in mice remains unknown. Here, we aimed to investigate, for the first time, the effects of 6′-SL on muscle functions. Seven-week-old male C57BL/6J mice were administered 100 mg/kg 6′-SL for 12 weeks, after which exhaustive treadmill performance, muscle strength, and muscle phenotype were examined. The administration of 6′-SL significantly improved exhaustive treadmill performance metrics, including distance and exhaustion time. Grip strength was also increased by 6′-SL administration. Additionally, 6′-SL increased muscle mass in both the gastrocnemius (GAS) and soleus. 6′-SL administration led to an increase in the minimum Feret’s diameter and the protein expression of total myosin heavy chain in the GAS muscle. In conclusion, 6′-SL administration in vivo led to increased running distance and time by increasing muscle mass and strength. These findings collectively indicate that 6′-SL is a potential agent for improving muscle health and exercise performance.

Lean body mass (LBM) is correlated with powerlifting performance in athletes competing in different bodyweight classes. However, it remains unknown whether changes in LBM are correlated with performance changes in powerlifters preparing for a competition. Aim of the study was to investigate the changes in LBM and performance in powerlifters preparing for a competition. Eight male powerlifters (age 31.7±9.8years, height 1.77±0.06m, weight 99.2±14.6kg) and three female powerlifters (age 32.7±16.3years, height 1.54±0.06m, weight 66.6±20.9kg), participated in the study. Athletes followed individualized periodized training programs for 12 weeks aiming to maximize their performance for the national championship. Maximum strength (1-RM) in squat, bench press, and deadlift, body composition, grip strength, anaerobic power, quadriceps’ cross sectional area and vastus lateralis muscle architecture were measured before and after the training period. Significant increases were found after the training period in squat (5.8±7.0%, P

Pigs are susceptible to cold stress due to the absence of brown fat caused by the partial deletion of uncoupling protein 1 during their evolution. Some local pig breeds in China, exhibit potential cold adaptability, but research has primarily focused on fat and intestinal tissues. Skeletal muscle plays a key role in adaptive thermogenesis in mammals, yet the molecular mechanism of cold adaptation in porcine skeletal muscle remains poorly understood. This study investigated the cold adaptability of two pig breeds, Mashen pigs (MS) and Large White pigs (LW), in a 4-day cold (4°C) or room temperature (25°C) environment. We recorded phenotypic changes and collected blood, and longissimus dorsi muscle for transcriptome sequencing. Finally, a candidate gene was randomly selected for functional exploration in porcine skeletal muscle satellite cells. A decrease in body temperature and body weight in both LW and MS pigs under cold stress, accompanied by increased shivering frequency and respiratory frequency. However, MS pigs demonstrated stable physiological homeostasis, indicating a certain level of cold adaptability. LW pigs primarily responded to cold stress by regulating heat production and Glycolipid energy metabolism. MS pigs exhibited a distinct response to cold stress, involving regulation of heat production, energy metabolism pathways, robust fatty acid oxidation ability, and stronger immune response. Furthermore, the functional exploration of PRSS8 in porcine skeletal muscle satellite cells revealed it affected cellular energy metabolism and thermogenesis by regulating ERK phosphorylation. These findings shed light on the diverse transcriptional responses of skeletal muscle in LW and MS pigs under cold stress, offering valuable insights into the molecular mechanisms underlying cold adaptation in pigs.

Chikungunya (CHIKV) and Mayaro (MAYV) viruses are arthritogenic alphaviruses that promote an incapacitating and long-lasting inflammatory muscle-articular disease. Despite studies pointing out the importance of skeletal muscle (SkM) in viral pathogenesis, the long-term consequences on its physiology after acute injury and the mechanism of persistence of symptoms are still poorly understood. Combining molecular, morphological, Nuclear Magnetic Resonance Imaging, and histological analysis, we conduct a temporal investigation of CHIKV and MAYV replication in a wild-type mice model, focusing on the impact on SkM composition, structure, and repair in the acute and late phases of infection. We found that viral replication and induced-inflammation promote fast loss of muscle mass and reduction of fibers cross sectional area, by inducing muscle-specific E3 ubiquitin ligases MuRF1 and Atrogin expression, that trigger protein breakdown, resulting in acute SkM fibers atrophy. After temporal reduction of inflammation and clearance of infectious viral particles, SkM atrophy persists until the late phase of infection. The genomic CHIKV and MAYV RNAs were still detected in SkM at the late phase, along with increased levels of chemokines and anti-inflammatory cytokines expression. In agreement with the involvement of inflammatory mediators on induced atrophy, neutralization of TNF and the reduction of oxidative stress using monomethyl fumarate, an agonist of Nrf2, decreases atrogens expression and atrophic fibers, while increasing weight gain in treated mice. Taken together, these data indicate that arthritogenic alphavirus infection could chronically impact body SkM composition and also harm repair machinery, contributing to a better understanding of mechanisms of arthritogenic alphaviruses pathogenesis and with description of potentially new targets of therapeutic intervention.

We aimed to determine whether A-mode ultrasound (US) can provide accurate and reliable measurements comparable to those obtained through B-mode US, under diverse conditions. Thirty healthy participants (15 female, 15 male) underwent measurements of subcutaneous fat thickness (SFT), muscle thickness (MT), and muscle quality (MQ) in the trapezius and biceps brachii muscle with both US modes after and before exercises designed to stimulate the respec-tive muscles. In three key indices, the results demonstrated high validity of A-mode, with min-imal mean differences between the two devices less than 0.91mm and intraclass correlation coef-ficients exceeding 0.95 at all measures. Also, Correlation coefficients between error scores and average scores for the trapezius and biceps brachii muscles suggested no evidence of systematic error. The trapezius MT and MQ significantly increased, and biceps brachii MT significantly in-creased after exercise (p<0.05). Notably, both A-mode and B-mode exhibited the same tendency in these post-exercise changes in muscle. This study suggests that low-cost and low-resolution A-mode US provides measurements of SFT, MT, and MQ similar to more expensive, high-resolution B-mode imaging. A-mode US can serve as an affordable and portable alternative for muscle assessment.

Near-Infrared Spectroscopy (NIRS) has been used to measure muscle mitochondrial capacity. The current method requires as many as 22 short ischemic occlusions to generate a recovery curve for mitochondrial capacity. PURPOSE: To determine the effectiveness of using a 6-occlusion analysis protocol to study muscle mitochondrial capacity. METHOD: Two independent, unidentified data sets were analyzed (bicep n=48, forearm n=41) from previous studies using a NIRS device (Artinis, Ltd.). Both data sets had two recovery tests that included 22 ischemic occlusions. A recovery rate used to indicate mitochondrial capacity was calculated two different ways (simultaneously). Each sample was analyzed with a MATLAB program; with a curve-fit for the 22 ischemic occlusions and curve matching for the first six ischemic cuffs and an end resting value. The two resulting rate constants were compared using correlations, both for the two data sets, good and bad fitting data, using the best 5 of 6 points for the 6 cuff approach. RESULTS: The rate constants were not significantly different between the 22 cmuff and 6 cuff for the total data sets: bicep (1.43+0.32min^-1, 1.44+0.35min^-1, p=0.56), forearm (1.94+0.42min^-1, 1.95+0.44min^-1, p=0.76). The average bicep rate constants, when compared to each other, had an equation of y=1.07x-0.09, R²=0.90. The average forearm rate constants, when compared to each other, had an equation of 0.98x+0.02, R²=0.93. CONCLUSIONS: The 6-Cuff analysis provided the same results as the longer 22-cuff. The 6-cuff approach is both shorter in time and uses less ischemic occlusion periods, increasing the practicality of the NIRS mitochondrial capacity test.

Muscle mass at admission is important to survive stroke, and stroke-induced sarcopenia is a serious problem because of its poor prognosis. Muscle mass measurement and monitoring are essential for appropriate re-habilitation and nutrition management. Several methods are used to assess skeletal muscle mass in stroke, such as computed tomography (CT), ultrasonography, bioelectrical impedance analysis, dual-energy X-ray absorptiometry, biomarkers, and anthropometrics. In stroke, a head CT is used to estimate muscle mass by measuring the temporal muscle. However, it is mostly retrospectively conducted due to radiation exposure. After stroke, limb muscle atrophy and diaphragm dysfunction are observed using ultrasound. However, ultrasound requires an understanding of the methods and skill. A bioelectrical impedance analysis can be used to assess muscle mass in patients after a stroke unless they have dynamic fluid changes. Dual-energy X-ray absorptiometry is used for follow-up after hospital discharge. Urinary titin N-fragment and serum C-terminal agrin fragment reflect muscle atrophy after stroke. Anthropometrics may be useful with limited resources. We summarized the features of each measurement and proved the recent evidence to properly measure and monitor skeletal muscle mass after stroke.

To win a taekwondo competition, more points must be scored, and the key to scoring points is to improve the motor performance of the kick. The wing kick is an offensive and defensive maneuver. Core stability appears to be important for improving athletic performance, but the specific relationship and effect of core stability on athletic performance in the aerial phase of taekwondo is unclear. The aim of this study was to investigate the relationship between core stability and athletic performance in taekwondo in order to provide appropriate theoretical support for training and to help coaches and athletes to improve athletic performance. A total of 16 subjects (height: 167.34±9.2 cm; weight: 61±8.96 kg; age: 24.7±3.25 years) were studied. Data were captured using 13 infrared cameras at 120Hz, kinematic and kinetic data were captured using a motivated motion capture system, and the data were exported to Visual3D in order to calculate the execution time of the aerial phase, the angular momentum of the left lower extremity, and MVC analysis of the EMG using EMG works. The core stability level of the subjects were measured using the Sahrmann Core Stability Test (SCST) to correlate with the other data, and then the subjects were grouped according to their core stability levels and the data from both groups were analyzed with t-tests. Results During the double fly lifting of aerial segments, SCST levels showed a very strong negative correlation with execution time (r= -0.739) and there was a statistically significant difference in execution time between high and low SCST levels (p &lt; 0.001), and the desired negative correlation was also seen in lower limb angular momentum X-axis (thigh r= -0.6294, shank r= -0.536, foot r= -0.6175), especially in the X-axis. The left rectus femoris (LRF) data had greater activation in the low SCST group(p=0.0019*). Through this experiment, we found that athletes with high core stability had faster execution times, lower angular momentum, and higher core muscle activation. Therefore, we conclude that incorporating core stability training into taekwondo training has the potential to improve kicking performance.

The correlation between pain and emotional status in subjects with temporomandibular disorders (TMD) is known. Regardless of that up to date these findings were seldomly confronted with the objective assessment of pain using a digital algometer on the mastication muscles. The aim of the study was to investigate the relationship between the emotional status, chronic pain pain pressure threshold (PPT). 38 subjects were screened for the existence of temporomandibular disorders with the 3Q/TMD questionnaire, for chronic pain (GCPS) and emotional status (PHQ-9 and GAD-7). The results were confronted with the PPT measured with the digital algometer on the masseter muscles. Each subject was examined three times (after 1 month and after 7 months from the initial exami-nation session. Chronic pain scores (GCPS) were found to be higher in the TMD group in all three examination sessions (p<0,05). The pain, depression and anxiety levels were higher in females de-spite the existence of TMD, but only some were significant.A correlation between chronic orofacial pain scores and PPT was found in 2 out of 3 examination sessions. The PPT scores on the masseter muscles did not correlate with the emotional state in the study population.

Objective: The main purpose of the study is to investigate the combined effects of polydeoxyribonucleotide (PDRN) and extracorporeal shock wave therapy (ESWT) sequences on the regenerative processes in atrophied animal muscles. Methods: Thirty male New Zealand rabbits, aged 12 weeks, were divided into five groups: normal saline, PDRN, ESWT, PDRN injection before ESWT, and PDRN injection after ESWT. Following 2 weeks of cast immobilization, the respective treatments were administered to the atrophied calf muscles. Radial ESWT was performed twice weekly. The evaluation included measurements of calf circumference, tibial nerve compound muscle action potential (CMAP), and gastrocnemius (GCM) muscle thickness after 2 weeks of treatment. Histological and immunohistochemical staining, as well as Western blot analysis, were conducted 2 weeks post-treatment. Staining intensity and extent were assessed using semi-quantitative scores. Results: Groups 4 and 5 demonstrated significantly greater calf muscle circumference, GCM muscle thickness, tibial nerve CMAP, and GCM muscle fiber cross-sectional area (types I, II, and total) than in the remaining three groups (p < 0.05), while they did not did not differ significantly in these parameters. Groups 2 and 3 showed the higher values for all the observations compared to group 1 (p < 0.05). Group 4 had the greatest ratio of vascular endothelial growth factor (VEGF) to platelet endothelial cell adhesion molecule-1 (PECAM-1) in the gastrocnemius muscle fibers than in the other four groups (p < 0.05). Western blot analysis revealed significantly higher expression of angiogenesis cytokines in groups 4 and 5 than in the remaining (p < 0.05). Conclusion: The combination of ESWT and PDRN injection demonstrated superior regenerative efficacy for atrophied calf muscle tissue in rabbit models than these techniques alone or saline. Particularly, administering ESWT after PDRN injection yielded the most favorable outcomes in specific parameters.

Despite ongoing efforts, the relationship between groin strength and injury remains unclear. The challenge of accurately predicting injuries presents an opportunity for researchers to develop pre-vention strategies to reduce the occurrence of such injuries. Consequently, this issue requires further investigation to obtain insights into effective mitigation strategies. In 120 male soccer players the maximum isometric strength of the hip muscle groups was measured, and the strength ratios were calculated. Previous injury and anthropometric data were registered. Injury data were collected following the FIFA/UEFA consensus. The K- Nearest Neighbour (k-NN), was used to predict the incidence of injury, while the significant predictive variables of the k-NN algorithm were fitted into a multivariate logistic regression model (LR) to analyze the likelihood of players sustaining a groin injury. The LR model determined two variables as significant predictors of groin injury. Players were less likely to sustain a groin injury by 76% for each decrease of the Adductors/Abductors isometric strength ratio in the non-dominant limb (OR = 0.238, CI 95%= [(0.098-0.572]). Players with a history of previous injury had a 67% greater risk of sustaining an injury (OR = 0.333, CI 95%= [(0.1068-1.038]). Isometric hip adductor and abductor strength im-balances of the non-dominant lower limb and a history of previous injury were risk factors for groin injury in soccer players.

Introduction: Obesity affects over 650 million individuals worldwide and it is a major public health problem. Bariatric surgery is the most effective treatment for severe obesity, resulting in significant weight reduction and improvement in obesity-related conditions. However, the weight loss achieved through bariatric surgery often correlates with a notable decrease in skeletal muscle. This correlation suggests an elevated risk of sarcopenia among patients after surgery. The aim of this study was to evaluate the effects of obesity and bariatric surgery on sarcopenia-related indicators and diagnosis before and after surgery. Methods: A total of 17 bariatric surgery patients were included in this prospective study. The parameters to diagnose sarcopenia were determined for each participant, based on EWGSOP2 and EASO/ESPEN consensuses. All evaluations were performed on the five moments of this study: before surgery and at 1, 6, 12 and 18 months after surgery. Results: In this study, 88.2% of the subjects were female, the mean BMI was 42.9 kg/m² and the mean weight was 105.9 kg. After surgery, the mean weight consistently decreased, with all differences from baseline being statistically significant (p<0.001). When using the SARC-F questionnaire for screening, the risk of sarcopenia increased post-surgery, and decreased at 12 months, declining to zero at 18 months. Muscle strength decreased significantly (p=0.002) at the 1 month after surgery assessment, with slight variations thereafter, none statistically significant. Muscle mass was normal before surgery but decreased significantly post-surgery (p<0.001). When applying the ESPEN/EASO consensus cut-off criteria for sarcopenic obesity, 35.3% of the patients met the criteria preoperatively. After surgery, the results increased to 70.6% in the first month but decreased afterward to 41.2% at 6 months. Discussion: This study evaluated the impact of bariatric surgery on sarcopenia and sarcopenic obesity, for a duration of up to 18 months after surgery, using the EWGSOP2 and ESPEN/EASO consensuses criteria. Bariatric surgery, the most effective treatment for severe obesity, often results in muscle mass loss alongside fat loss. Handgrip strength, a key sarcopenia indicator, showed a significant early post-surgery decline, whereas the weight-dependent sit-to-stand test did not. This suggests weight loss impacts different muscle function tests variably. Muscle mass decreased continuously after surgery. However, other indicators had mixed results. Applying ESPEN/EASO guidelines, the study found a temporary post-surgery increase in sarcopenic obesity, peaking at one month and returning to pre-surgery levels by six months. However, different criteria led to different results. Conclusion: The results indicate a clear deleterious impact of bariatric surgery on muscle strength and mass, the most important indicators of sarcopenia. Also, the impact seems to occur very early after surgery, indicating that the appropriate timeframe to try to prevent this effect may be the prehabilitation period followed by the post-surgery timeframe.

Background Sarcopenia is a state with progressive and generalized loss of skeletal muscle mass and strength. It is a serious complication occurring in chronic kidney disease (CKD) patients which increases morbidity and mortality rate. Sarcopenia is diagnosed when loss of both compartments - muscle strength and skeletal muscle quality or quantity are present. However, there are still numerous patients, also with CKD, diagnosed as pre-sarcopenic individuals with low muscle strength and normal skeletal muscle quality or quantity and conversely, with correct muscle strength and decreased skeletal muscle mass, who are prone to develop sarcopenia in future life. It is crucial to examine numerous variables possibly associated with changes of skeletal muscle mass and muscle strength in terms of preventing the development of sarcopenia. The aim of the study was to investigate anthropometric and clinical correlates and sources of variation in both skeletal muscle mass and muscle strength in advanced stages of CKD. Methods The study sample consisted of 84 non-dialysis dependent patients of both sexes (including 45.2% of women) with eGFR < 45 ml/min/1.73m²: 26.2% with eGFR 30-44 mL/min/1.73 m², 65.5% with eGFR 15-29 mL/min/1.73 m² and 8.3% with eGFR < 15 mL/min/1.73 m². Muscle strength was estimated by measuring hand grip strength (HGS) with the use of handheld hydraulic dynamometer. Muscle quantity was measured by bioimpedance spectroscopy using Body Composition Monitor. Appendicular skeletal muscle mass (ASM) was calculated according to Lin’s formula. Serum creatinine, urea, uric acid and albumin were measured. Results In bivariate analysis we found that ASM significantly and positively correlated with anthropometric variables such as body mass (r=0.903, p<0.001), NH weight (r=0.882, p<0.001), height (r=0.694, p<0.001), body mass index (BMI) (r=0.701, p<0.001), lean tissue mass (LTM) (r=0.664, p<0.001), lean tissue index (LTI) (r=0.433, p<0.001), fat mass (r=0.614, p<0.001) and fat tissue index (FTI) (r=0.449, p<0.001), and was negatively associated with clinical variable such as hydration status (p<0.001). HGS significantly and positively correlated with anthropometric parameters such as body mass (r=0.319, p=0.003), NH weight (r=0.315, p=0.004), height (r=0.666, p<0.001), LTM (r=0.490, p<0.001), LTI (r=0.238, p=0.029), and ASM (r=0.501, p<0.001), and was negatively associated with clinical variables like uric acid (p=0.039) and urea (p<0.001). After adjustment for age, sex and height, HGS remained significantly and negatively related with uric acid (β=-1.078, p=0.041) and hydration status (β=-0.805, p=0.042). Conclusions In CKD patients, ASM is determined mainly by anthropometric parameters but HGS - both by anthropometric and clinical variables specific for CKD.

Striated muscle thick filaments are composed of myosin II and several non- myosin proteins which define the filament length and modify its function. Myosin II has a globular N-terminal motor domain comprising its catalytic and actin-binding activities and a long α-helical, coiled-coil tail that forms the dense filament backbone. Myosin alone polymerizes into filaments of irregular length, but striated muscle thick filaments have defined lengths that with the thin filament define the sarcomere structure. The motor domain structure and function are well understood but the myosin filament backbone is not. Here we report a structure of the flight muscle thick filaments from Drosophila melanogaster at 4.7 Å resolution which eliminates previous ambiguities in the non-myosin densities. The full proximal S2 region is resolved as are the connecting densities between the Ig domains of stretchin-klp. The proteins, flightin and myofilin are resolved in sufficient detail to build an atomic model based on an AlphaFold prediction. Our results suggest how flightin and myofilin cooperate to define the structure of the thick filament and explains a key myosin mutation that affects flightin incorporation. Drosophila is a genetic model organism for which our results can define strategies for functional testing.

The ryanodine receptor (RyR) is a Ca2+ release channel in the sarcoplasmic reticulum of skeletal and cardiac muscles and plays a key role in excitation-contraction coupling. The activity of the RyR is regulated by many intracellular factors such as divalent cations (Ca2+ and Mg2+), nucleotides, associated proteins, and reactive oxygen species. Since these intracellular factors change depending on the condition of the muscle, e.g., exercise, fatigue, or disease states, the RyR channel activity will be altered accordingly. In this review, we describe how the RyR channel is regulated under various conditions and discuss the possibility that the RyR acts as a sensor for change in the cellular environment of muscles.

Adaptation to external forces relies on a well-functioning proprioceptive system including muscle spindle afferents. Muscle length-tension control in reaction to external forces is most important regarding the Adaptive Force (AF). This study investigated the effect of different procedures, which are assumed to influence the function of muscle spindles, on the AF. 19 elbow flexors of 12 healthy participants were assessed by an objectified manual muscle test (MMT) with different procedures: regular MMT, MMT after pre-contraction (self-estimated 20% MVIC) in lengthened position with passive return to test position (CL) and MMT after CL with a second pre-contraction in test position (CL-CT). During regular MMTs, muscles maintained their length up to 99.7±1.0% of the maximal AF (AFmax). After CL, muscles started to lengthen at 53.0±22.5% of AFmax. For CL-CT, muscles were again able to maintain the isometric position up to 98.3±5.5% of AFmax. AFisomax differed highly significantly between CL vs. CL-CT and regular MMT. CL is assumed to generate a slack of muscle spindles which led to a substantial reduction of the holding capacity. This was immediately erased by a pre-contraction in test position. The results substantiate that muscle spindle sensitivity seems to play an important role for neuromuscular functioning and musculoskeletal stability.

The involvement of the angiotensin II type 1 receptor in the Frank-Starling Law of the Heart, where the various activations are very limited, allows simple analysis of the kinase systems involved and thence extrapolation of the mechanism to that of angiotensin control of activation of cardiac and skeletal muscle contraction. The involvement of phosphorylation of the myosin light chain in the control of contraction is accepted but not fully understood. The involvement of troponin-I phosphorylation is also indicated but of unknown mechanism. There is no known signal for activation of myosin light chain kinase or Protein Kinase C-βII other than Ca²⁺/calmodulin but the former is constitutively active and thus has to be under control of a regulated inhibitor, the latter kinase may also be the same. Ca²⁺/calmodulin is not activated in Frank-Starling, i.e. there are no diastolic or systolic [Ca²⁺] changes. I suggest here that that the regulated inhibition is by myosin light chain phosphatase and/or β-arrestin. Angiotensin activation is by translocation of the β-arrestin from the sarcoplasm to the PM thus reducing its kinase inhibition action in the sarcoplasm, this reduced inhibition has been wrongly attributed to a mythical downstream agonist property of β-arrestin.

In the face of rising global demand and unsustainable production methods, cultivated crustacean meat (CCM) is proposed as an alternative means to produce delicious lobster, shrimp and crab products. Cultivated meat requires starting stem cells that may vary in terms of potency, and propensity to proliferate or differentiate into myogenic (muscle-related) tissues. We suggest that regenerating crustacean limbs harbor a range of stem cells suitable for cultivated meat production and present a humane tissue source because they can be accessed non-lethally. To investigate stem cell activity in this model, we have conducted RNA-Seq analysis across six stages of claw regeneration in the crayfish Cherax quadricarinatus (four pre-molt and two post-molt stages), along with histology and real time quantitative PCR (qPCR). Differential expression analysis revealed expression patterns of significantly up- or down-regulated genes in 14 functional categories. Relative expression of select stem cell target genes (including endocrine, myogenic, cell cycle and pluripotency factors) highlighted two growth peaks during pre-molt regeneration and limited stem cell activity after the molt. Histology and qPCR results support the overall finding that pre-molt limb regeneration stages harbor more stem cell activity, likely making them a more prolific cell source for CCM development.

An untrained couch potato involuntarily forced to undergo a long strenuous exercise towards exhaustion will feel it at the end as a discomforting fatigue. A well-trained athlete will feel the same but after a longer time. Patients of various neurological diseases will do so much earlier. All may also finally experience muscle pain and soreness the next day.Muscle fatigue is an exercise-induced reduction in maximal voluntary muscle force. Muscle fatigability varies with muscle use, age and sex. It is commonly divided into two broad categories: peripheral and central fatigue. The first refers to the many processes in the fatiguing muscle(s), the second to subsequent processes in the central nervous system (CNS). Peripheral muscle fatigue can be caused by numerous different mechanisms, ranging from the accumulation of metabolites within muscle fibers to their damage. Central fatigue involves the inadequacy of the CNS to generate and maintain sufficiently strong motor command. There must of course be a mediator relating the two fatigue types, and this is the collection of small-diameter group III (Aδ) and IV (C) nerve fibers emanating from the muscle and distributing their activation effects throughout the CNS.Muscle fatigue develops during eventually exhausting exercise that goes along with activations of the cardio-vascular and respiratory system to supply oxygen and energy resources. While these functions are supported by a number of sensory afferents, fatigue-activated group III/IV muscle afferents have been proposed to contribute their share to cardio-vascular and ventilatory reflex responses that are mediated in the brainstem. Neural feedback from working skeletal muscle is a vital component in providing a high capacity for endurance exercise because muscle perfusion and O₂ delivery determine the fatigability of skeletal muscle (Amann 2012).The development of chronic muscle fatigue is related to muscle wasting mediated by aging, myopathies, muscle dystrophies, immobilization, insulin resistance, diseases associated with systemic inflammation (arthritis, sepsis, infections), trauma, cardio-vascular (heart failure) and respiratory disorders (chronic obstructive pulmonary disease (COPD)), chronic kidney failure, multiple sclerosis (MS), and, more recently, coronavirus disease 2019 (COVID-19).

Background: The thoracolumbar fascia (TLF) is thought to play a role in the development of LBP, but it is not yet clear which factor of TLF changes is a cause and which is an effect. Therefore, some studies used the cross-correlation function (CCR) to reveal time-dependent relationships between biomechanical and neuromotor factors. Methods: Ten patients with acute low back pain (aLBP) were matched to healthy controls. Simultaneous recording of surface electromyography (sEMG) of the erector spinae muscle (ES) and dynamic ultrasound (US) images of TLF deformation were performed during trunk extension. CCR functions and Granger causality were used to describe the relationship between the two measures. Results: CCR time lags were significant higher in the aLBP group (p = 0.04). Granger causality (GC) showed a direct effect of TLF deformation on ES activation only in the aLBP group (p &lt; 0.03). Conclusions: The results suggest that in aLBP, ES activity is significantly affected by TLF, whereas this relation-ship is completely random in healthy subjects studied with CCR and GC comparisons of dynamic US imaging and sEMG data signals. Fascia-related disturbances in neuromotor control, particularly due to altered muscle spindle functions, are suspected as a possible mechanism behind this.

Background: Appendicular skeletal muscle (or lean) mass (ALM) estimated using dual-energy X-ray absorptiometry (DXA) is considered to be a preferred method for sarcopenia studies. However, DXA is expensive, has limited portability, and requires radiation exposure. Bioelectrical impedance analysis (BIA) is inexpensive, easy to use, and portable; thus BIA might be useful in sarcopenia investigations. However, a large variety of models have been commercially supplied by different companies, and for most consumer products, the equations estimating ALM are not disclosed. It is therefore difficult to use these equations for research purposes. In particular, the BIA equation is often age-dependent, which leads to fundamental difficulty in examining age-related ALM loss. The aims of the current study were as follows: (1) to develop and validate an equation to estimate ALM using multi-frequency BIA (MF-BIA) based on theoretical models, and (2) to establish sarcopenia cutoff values using the equation for the Japanese population. Methods: We measured height (Ht), weight, and ALM obtained using DXA and a standing-posture 8-electrode MF-BIA (5, 50, 250 kHz) in 756 Japanese individuals aged 18 to 86-years-old (222 men and 301 women as developing equation group and 97 men and 136 women as a cross validation group). The traditional impedance index (Ht²/Z₅₀) and impedance ratio of high and low frequency (Z₂₅₀/Z₅) of hand to foot values were calculated. Multiple regression analyses were conducted with ALM as dependent variable in men and women separately. Results: We created the following equations: ALM = (0.6947 × (Ht²/Z₅₀)) + (−55.24 × (Z₂₅₀/Z₅)) + (−10,940 × (1/Z₅₀)) + 51.33 for men, and ALM = (0.6144 × (Ht²/Z₅₀)) + (−36.61 × (Z₂₅₀/Z₅)) + (−9332 × (1/Z₅₀)) + 37.91 for women. Additionally, we conducted measurements in 1624 men and 1368 women aged 18 to 40 years to establish sarcopenia cutoff values in the Japanese population. The mean values minus 2 standard deviations of the skeletal muscle mass index (ALM/Ht²) in these participants were 6.8 and 5.7 kg/m² in men and women, respectively. Conclusion: The current study established and validated a theoretical and age-independent equation using MF-BIA to estimate ALM and provided reasonable sarcopenia cutoff values.

This study assessed the potential of back extensor strength as an alternative marker of frailty. A total of 560 farmers were included. Computed tomography scans measured fat and muscle mass volumes at the mid-L4 vertebral level. Back extensor strength was measured in a seated posture. Multivariate linear regression analyzed the associations between back extensor strength and trunk muscle/fat compositions. The participants were divided into two groups based on back extensor strength. Propensity score matching, multivariate logistic regression, and Extreme Gradient Boosting (XGBoost) were employed to evaluate the relationship between Fried's frailty criteria and back extensor strength. Back extensor strength exhibited positive associations with abdominal muscle volume (r = 1.12) as well as back muscle volume (r = 0.89) (p < 0.05). Lower back extensor strength was linked to more frail status, such as reduced grip strength, walking speed, and fre-quent self-reported exhaustion. Multivariate logistic regression indicated a significant association between lower back extensor strength and higher Fried frailty score (OR, 0.990; p<0.05). XGBoost analysis identified back extensor strength as the most important predictor (gain = 0.502) for frailty, surpassing the significance of age (gain = 0.325). These findings suggested the potential of back extensor strength as an alternative frailty marker.

Purpose: Physical activity (PA) is likely the most important modifiable element for the growth of skeletal muscle. However, a detailed investigation of PA’s impact on preschoolers’ of skeletal muscle development is lacking. This study aimed to determine whether PA level is related to skeletal muscle thickness among preschool children. Methods: 275 healthy preschoolers between the ages 4–6 were instructed to wear an accelerometer for 4 consecutive days. The daily steps and minutes spent in moderate-to-vigorous PA (MVPA) and total PA (TPA) were examined. Muscle thickness (MT) was measured by B-mode ultrasonography. The MT was measured at the anterior (AT) and posterior thigh (PT) and the anterior (AL) and posterior lower leg (PL). Results: Boys were more physically active and engaged in significantly more TPA and MVPA on weekdays compared with girls. Compared with that on the weekends, more physical activity, and significantly greater number of daily steps and higher TPA and MVPA were recorded for both boys and girls on the weekdays. Multivariable regression analyses, after adjusting for daylight duration, indicated that a daily increase in the TPA and MVPA would lead to higher muscle size in AT (β=1.11 and β=1.37, p<0.05), and PL (β=1.18 and β=0.94, p<0.05) among preschool children. Conclusions: The time spent involved in most of the different categories of MVPA was significantly higher for boys than for girls on the weekdays and weekends. MVPA was positively correlated with greater skeletal muscle development in the lower body.

Fullerene nanomaterials exposure often causes a variety of diseases. Many studies have pointed out that fullerene nanomaterials can be studied in fish. However, there are few studies on health risk assessment of clownfish with lower doses of fullerene nanoparticles or different exposure durations. In this study, we set 1.5% and 3.0% for low- and high-dose fullerene nanomaterials exposure concentrations, respectively. Meanwhile, we performed a time-series analysis to investigate that the activation of lipid and amino acids metabolism after fullerene nanomaterials exposure in clownfish. 1368 metabolites were detected from clownfish by using liquid chromatography-mass spectrometry (LC-MS) analyses. Our results suggest that exposure to lower fullerenes nanoparticles may have a certain promoting effect on clownfish overall length, body length and weight. At the same time, the activation of potential metabolic pathways enriched by different metabolites in KEGG pathway may also indicate the positive promoting effect of fullerene nanoparticles after exposure. The present work indicates that it is particularly important to find the concentration window for fullerene nanomaterials to improve government safety guidelines, especially when these are applied to assess the health risk of human.

Objective: The purpose of this study is to compare the effects of stretching methods for flexibility, muscle activation, and pressure pain threshold in ballet dancers, and to suggest an effective stretching method. Methods: Thirty-three ballet dancers were randomized to a static stretching group (n=11), muscle energy technique stretching group (n=11), and vibration-assisted stretching group (n=11). The angle of hip joint extension in arabesque, the activation of rectus femoris in Devéloppé, and the pressure pain threshold on rectus femoris in sitting position were measured to compare the effects of different stretching methods. Results: Hip joint extension angles increased in all stretching methods (p<0.05), however, vibration-assisted stretching and muscle energy technique stretching were more effective than static stretching (p<0.05). The activation of the rectus femoris decreased in all groups (p<0.05), but the muscle energy technique stretching group and the vibration-assisted stretching group showed a significant decrease compared to the static stretching group (p<0.05). The pressure pain threshold showed significant improvement only in the static stretching group (p<0.05), and the vibration-assisted stretching group (p<0.05). Conclusion: Vibration-assisted stretching compared to static stretching and muscle energy technique stretching is a beneficial method for flexibility, muscle activation, and pressure pain threshold in ballet dancers.

Background: The chin tuck maneuver has been suggested to increase suprahyoid muscle activation, but a method to measure the strength of the chin tuck maneuver has not been established. We developed a method to measure the strength of the chin tuck maneuver (chin tuck strength) and examined the reliability and validity of chin tuck strength measurement in community-dwelling older adults. Subjects and Methods: The participants were 233 older adults aged ≥65 years without dysphagia or physical disability. Chin tuck strength was measured twice consecutively using the developed device, and reproducibility was analyzed using intraclass correlation coefficients (ICCs). In addition, maximum tongue pressure, oral diadochokinesis, grip strength, knee extension strength, and the timed up and go test (TUGT) were measured as indices of swallowing-related muscle function and appendicular muscle function. The associations of chin tuck strength with swallowing-related muscle function and appendicular muscle function were analyzed statistically. Results: The ICCs for chin tuck strength were 0.82 (95% confidence interval [CI]: 0.73-0.88) in males and 0.87 (95%CI: 0.70-0.93) in females. Chin tuck strength was significantly associated with maximum tongue pressure, grip strength, knee extension strength, and TUGT. Conclusions: This study suggests that chin tuck strength is a reliable and valid assessment of swallowing-related muscle strength.

The agonist-antagonist myoneural interface (AMI), a surgical method to reinnervate physiologically-relevant proprioceptive feedback for control of limb prostheses, has demonstrated the ability to provide natural afferent sensations for limb amputees when actuating their prostheses. Following an AMI surgery, one potential challenge is atrophy of the disused muscles, which would weaken the reinnervation efficacy of AMI. It is well known that electrical muscle stimulus (EMS) can reduce the muscle atrophy. In this study, we conducted an animal investigation to explore whether the EMS can significantly improve the electrophysiological performance of AMI. The AMI surgery was performed in 14 rats, in which the distal tendons of bilateral solei donors were connected and positioned on the surface of the left biceps femoris. Subsequently, the left tibial nerve and the common peroneus nerve were sutured onto the ends of the connected donor solei. Two stimulation electrodes were affixed onto the ends of the donor solei for EMS delivery. The AMI rats were randomly divided into two groups. One group regularly received the EMS treatment (designated as EMS_on) for eight weeks and another was no EMS (designated as EMS_off). Two physiological parameters, nerve conduction velocity (NCV) and motor unit number, were derived from the electrically evoked compound action potential (CAP) signals to assess the electrophysiological performance of AMI. Our experimental results demonstrated that the reinnervated muscles of the EMS_on group generated higher CAP signals in comparison to the EMS_off group. Both NCV and motor unit number were significantly elevated in the EMS_on group. Moreover, the EMS_on group displayed statistically higher CAP signals on the indirectly activated proprioceptive afferents than the EMS_off group. These findings may suggested that the EMS treatment would be promise in enhancing the electrophysiological performance and facilitating the reinnervation process of AMI.

Background: Despite the tremendous effort in hamstring injury prevention, injury rates in soccer remain elevated. Hypothesis: Hamstring and hip/pelvic isometric strength imbalances may increase the likelihood of hamstring strain injury (HSI) occurrence amongst soccer players.Study design: Case-control study.Methods: In 120 male soccer players (mean age: 20.0 +/- 6.96 years) pre-season maximum isometric strength of the hip adductors, abductors, flexors, and knee flexors were measured, and strength ratios were calculated. Previous injury and anthropometric data were registered. Injury data were collected following the FIFA/UEFA consensus. A multivariate and Machine learning-based Logistic Regression model was employed to estimate the likelihood of players sustaining a hamstring injury.Results: 21 players sustained 32 hamstring injuries. Players with higher abduction strength in the dominant leg had an 18.5% lower risk of sustaining a hamstring injury (OR = 0.818, CI 95% = [(0.695-0.964]). No other significant contributor variables were found to be significant predictors of hamstring injury in the player group (p> 0.05).Conclusion: Isometric strength of the abductor muscles in the dominant limb had a significant association with hamstring injury.Clinical relevance: Our findings indicate the utilization of hip strength measurements as an integral component of the pre-season screening assessment, thereby affirming prior research on the correlation between lumbo-pelvic stability and incidence of hamstring injuries. Consequently, clinicians should contemplate incorporating hip strengthening exercises into regular training sessions, rehabilitation programs, and injury prevention protocols especially indicated when lower hip strength levels are observed.

The normal growth and development of skeletal muscle is essential for the health of the body. The regulation of skeletal muscle by intestinal microorganisms and their metabolites has been continuously revealed. Acetate is the predominant short-chain fatty acid synthesized by gut microbiota through the fermentation of dietary fiber, however, the underlying molecular mechanisms governing the interaction between acetate and skeletal muscle during rapid growth stage remain to be further elucidated; Here, specific pathogen-free (SPF) mice, germ-free (GF) mice, and germ-free mice supplemented with sodium acetate (GS) were used to evaluate the effects of acetate on skeletal muscle growth and development of young mice with gut microbiota deficiency; We found the concentration of serum acetate, body mass gain, succinate dehydrogenase activity and expression of myogenesis maker gene of skeletal muscle in the GS group was higher than GF group following sodium acetate supplement. Furthermore, the transcriptome analysis revealed that acetate activated biological processes regulating skeletal muscle growth and development in GF group that are inhibited due to gut microbiota deficiency. In vitro experiment, we proved that acetate up-regulated Gm16062 to promote skeletal muscle cell differentiation; Overall, our findings proved that acetate promote skeletal muscle growth and development in young mice via increase Gm16062 expression.

With an increase in proportion of elderly patients, the global burden of spinal disease is on the rise. Likewise, there has been an increasing trend in the number of spine surgeries being performed worldwide. As we know, rehabilitation following spine surgery is critical for optimal recovery. However, current literature lacks consensus regarding the appropriate post operative rehabilitation protocol. The goals of rehabilitation after lumbar spine surgery are to improve physical and psychosocial function and may include multiple modalities such as physical therapy, cognitive behavioral therapy, specialized instruments, and instruction to be followed during activities of daily living. In recent years, not only are a greater number of spine surgeries being performed, various different techniques of lumbar spine surgery and spinal fusion have emerged. Physical therapy programs need to be curated after assessing the functional status of the patient by using various patient reported outcome measures and taking into consideration the technique of spinal fusion used and the muscle groups involved in these surgeries. By doing so it is possible to assess the level of functional impairment and then specifically target strengthening of those muscle groups affected by surgery whilst also improving impaired balance and allowing return to activities of daily living. We reviewed available literature pertaining to the history of spinal rehabilitation, the popular patient reported outcome measures used and different rehabilitation methods with the purpose of summarizing the current guidelines for postoperative rehabilitation after spine surgery and to introduce the rehabilitation after lumbar surgeries that we provide at our hospital.