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Objective: Passive stiffness, a biomechanical parameter, has a potential influence on running economy, thus playing a pivotal role in performance. This study aimed to quantify passive stiffness of the Achilles tendon and gastrocnemius muscle using myotonometry throughout an incremental running protocol. Methods: Twenty-one male participants underwent a multistage incremental test (Bordeaux test) on a treadmill until exhaustion. Passive stiffness of the gastrocnemius muscle and Achilles tendon was measured using a MyotonPRO device. Measurements were taken before, during, and after the incremental test. Results: Our findings indicated that passive stiffness of the medial gastrocnemius decreased at rest between prerun and postrun assessments (−20.12 N·m−1, P =.012). Furthermore, during the test, stiffness increased at low intensity (at 50% of maximal aerobic speed: +104.8 N·m−1, P =.042), returning to baseline values as intensity increased. Conclusions: Throughout an incremental running protocol, both Achilles tendon and gastrocnemius muscle stiffness initially increased and then decreased with escalating percentages of maximal aerobic speed. A deeper understanding of stiffness in running can inform more effective recommendations for runners' strengthening and training. [ABSTRACT FROM AUTHOR]

Purpose: Performing back squats with elastic bands has been widely used in resistance training. Although research demonstrated greater training effects obtained from adding elastic bands to the back squat, little is known regarding the optimal elastic resistance and how it affects neuromuscular performance. This study aimed to compare the force, velocity, power, and muscle activity during back squats with different contributions of elastic resistance. Methods: Thirteen basketball players performed 3 repetitions of the back squat at 85% of 1-repetition maximum across 4 conditions: (1) total load from free weight and (2) 20%, (3) 30%, and (4) 40% of the total load from elastic band and the remaining load from free weight. The eccentric and concentric phases of the back squat were divided into upper, middle, and bottom phases. Results: In the eccentric phase, mean velocity progressively increased with increasing elastic resistance, and muscle activity of the vastus medialis and rectus femoris significantly increased with the largest elastic resistance in the upper phase (P ≤.036). In the concentric phase, mean power (P ≤.021) and rate of force development (P ≤.002) significantly increased with increasing elastic resistance. Furthermore, muscle activity of the vastus lateralis and vastus medialis significantly improved with the largest elastic resistance in the upper phases (P ≤.021). Conclusion: Velocity, power, rate of force development, and selective muscle activity increased as the elastic resistance increased in different phases during the back-squat exercise. [ABSTRACT FROM AUTHOR]

Background: Local high-frequency percussive (HFP) massage has recently found widespread application in physical therapy. Although HFP massage reportedly improves range of motion (ROM), the mechanism underlying its action has not yet been proven. This study aimed to clarify whether a 5-minute percussive massage regimen affects muscular or connective tissues, such as the deep fascia and deep intermuscular fascia and the change in joint ROM. Method: The study sample was calculated using G*Power analysis program, and this study enrolled 15 healthy men who underwent 5-minute HFP massage to the medial gastrocnemius muscle. Shear-wave elastography was used to measure tissue stiffness in the deep fascia, muscle, and deep intermuscular fascia through shear-wave velocity as well as the ROM of the volunteers' ankle joint dorsiflexion before and after the HFP massage. A value of P < .05 was used to declare statistical significance, and post hoc was used to calculate the effect size using G*Power. Results: Shear-wave velocity revealed a significant change in the deep fascia (P = .003; shear-wave velocity: -0.7 m/s) and significant increase in ROM of ankle dorsiflexion (P = .002; increase in ROM: 3.0°) after 5 minutes of HFP massage. However, the muscle and deep intermuscular fascia did not exhibit any significant changes. Conclusions: HFP massage for 5 minutes modified the stiffness of the deep fascia and concurrently improved the ankle joint-dorsiflexion ROM. This method can be used as an intervention to decrease stiffness of the deep fascia and increase the ROM efficiently. [ABSTRACT FROM AUTHOR]

A correction to the article "Match Running Performance in Australian Football is Related to Muscle Fiber Typology" that was published in the October 10, 2023 online issue is presented.

Context: Decreased muscle strength and balance in patients with functional ankle instability (FAI) can be effectively improved by ankle strength training. Low-load blood flow restriction (LL-BFR) training increases muscle size and strength, but there is limited evidence from studies on muscle strength and balance in FAI patients. Objective: To study the effects of LL-BFR training versus high-load training (HLT) on muscle strength and balance in FAI patients. Design: Randomized controlled trial. Participants: Forty-six young adults with a history of FAI. Interventions: Participants in the LL-BFR and HLT groups performed 4 sets (30 x 15 x 15 x 15) of ankle training at 20% to 40% of the one-repetition maximum and 70% to 85% one-repetition maximum, respectively, twice a week for 6 weeks. Main Outcome Measure(s): Plantar flexion, dorsiflexion, inversion, and eversion muscle strength, and the Y-balance test scores were assessed at baseline and after 3 and 6 weeks; the thickness of the tibialis anterior, triceps surae, and peroneus longus muscles were assessed at baseline and after 6 weeks. Results: Inversion, eversion, dorsiflexion, and plantar flexion muscle strength; tibialis anterior, triceps surae, and peroneus longus thickness; and Y-balance test scores were significantly increased in the LL-BFR group after 3 and 6 weeks compared with baseline (P < .05), with no significant difference between the LL-BFR and HLT groups after 6 weeks (P > .05). However, at the end of 3 weeks, eversion muscle strength and Y-balance test scores were significantly higher in the LL-BFR group than in the HLT group (P < .05). Conclusions: Over 6 weeks, LL-BFR training was as effective as HLT in improving ankle muscle strength, muscle thickness, and balance in FAI patients, but LL-BFR training improved the ankle eversion muscle strength and dynamic balance more than HLT did in the early stages of the intervention. This finding will provide a new intervention strategy for the clinical rehabilitation of FAI patients. [ABSTRACT FROM AUTHOR]

Spasticity is a common impairment within pediatric neuromusculoskeletal disorders. How spasticity contributes to gait deviations is important for treatment selection. Our aim was to evaluate the pathophysiological mechanisms underlying gait deviations seen in children with spasticity, using predictive simulations. A cluster analysis was performed to extract distinct gait patterns from experimental gait data of 17 children with spasticity to be used as comparative validation data. A forward dynamic simulation framework was employed to predict gait with either velocity- or force-based hyperreflexia. This framework entailed a generic musculoskeletal model controlled by reflexes and supraspinal drive, governed by a multiobjective cost function. Hyperreflexia values were optimized to enable the simulated gait to best match experimental gait patterns. Three experimental gait patterns were extracted: (1) increased knee flexion, (2) increased ankle plantar flexion, and (3) increased knee flexion and ankle plantar flexion when compared with typical gait. Overall, velocity-based hyperreflexia outperformed force-based hyperreflexia. The first gait pattern could mostly be explained by rectus femoris and hamstrings velocity-based hyperreflexia, the second by gastrocnemius velocity-based hyperreflexia, and the third by gastrocnemius, soleus, and hamstrings velocity-based hyperreflexia. This study shows how velocity-based hyperreflexia from specific muscles contributes to different spastic gait patterns, which may help in providing targeted treatment. [ABSTRACT FROM AUTHOR]

In this narrative review, we explore developments in the field of computational musculoskeletal model personalization using the Physiome and Musculoskeletal Atlas Projects. Model geometry personalization; statistical shape modeling; and its impact on segmentation, classification, and model creation are explored. Examples include the trapeziometacarpal and tibiofemoral joints, Achilles tendon, gastrocnemius muscle, and pediatric lower limb bones. Finally, a more general approach to model personalization is discussed based on the idea of multiscale personalization called scaffolds. [ABSTRACT FROM AUTHOR]

Calf circumference (CC) is an easy measure of muscle loss; yet, there are limited studies in children. We aimed to assess the viability of the first-week percent change in CC as a prognostic nutritional marker. Two MUAC (mid-upper arm circumference), CC, and weight measurements were carried out: one on the first day of admission and another on the seventh day. The differences and correlations between their percent changes were examined. The possible association between CC percent change and prolonged length of hospital stay (PLOS) and in-hospital mortality was assessed. Seventy participants were enrolled with a median age of 19.5 months. The median (interquartile range [IQR]) of CC percent change was 0.54 (5.5) with significant correlations between it and each of MUAC and weight percent change (ρ = 0.928, P =.001), (ρ = 0.902, P =.001), respectively. Calf circumference percent changes were significantly more negative in children with PLOS; (P =.004). These changes seem to be viable measures of nutritional status. [ABSTRACT FROM AUTHOR]

This work aims to develop and implement a pulse‐acquire sequence for three‐dimensional (3D) single‐voxel localized 13C MRS in humans at 7 T, in conjunction with bilevel broadband 1H decoupling, and to test its feasibility in vitro and in vivo in human calf muscle with emphasis on the detection of glycogen C1‐C6. A localization scheme suitable for measuring fast‐relaxing 13C signals in humans at 7 T was developed and implemented using the outer volume suppression (OVS) and one‐dimensional image selected in vivo spectroscopy (ISIS‐1D) schemes, similar to that which was previously reported in humans at 4 T. The 3D 13C localization scheme was followed by uniform 13C adiabatic excitation, all complemented with an option for bilevel broadband 1H decoupling to improve both 13C sensitivity and spectral resolution at 7 T. The performance of the pulse‐acquire sequence was investigated in vitro on phantoms and in vivo in the human calf muscle of three healthy volunteers, while measuring glycogen C1‐C6. In addition, T1 and T2 of glycogen C1‐C6 were measured in vitro at 7 T, as well as T1 of glycogen C1 in vivo. The glycerol C2 and C1,3 lipid resonances were efficiently suppressed in vitro at 7 T using the OVS and ISIS‐1D schemes, allowing distinct detection of glycogen C2‐C6. While some glycerol remained in calf muscle in vivo, the intense lipid at 130 ppm was efficiently suppressed. The 13C sensitivity and spectral resolution of glycogen C1‐C6 in vitro and glycogen C1 in vivo were improved at 7 T using bilevel broadband 1H decoupling. The T1 and T2 of glycogen C1‐C6 in vitro at 7 T were consistent compared with those at 8.5 T, while the T1 of glycogen C1 in vivo at 7 T resulted similar to that in vitro. Localized 13C MRS is feasible in human calf muscle in vivo at 7 T, and this will allow further extension of this method for 13C MRS measurements such as in the brain. [ABSTRACT FROM AUTHOR]

Purpose: To optimize Relaxation along a Fictitious Field (RAFF) pulses for rotating frame relaxometry with improved robustness in the presence of B0$$ {\mathrm{B}}_0 $$ and B1+$$ {\mathrm{B}}_1^{+} $$ field inhomogeneities. Methods: The resilience of RAFF pulses against B0$$ {\mathrm{B}}_0 $$ and B1+$$ {\mathrm{B}}_1^{+} $$ inhomogeneities was studied using Bloch simulations. A parameterized extension of the RAFF formulation was introduced and used to derive a generalized inhomogeneity‐resilient RAFF (girRAFF) pulse. RAFF and girRAFF preparation efficiency, defined as the ratio of the longitudinal magnetization before and after the preparation (Mz(Tp)/M0$$ {M}_z\left({T}_p\right)/{M}_0 $$), were simulated and validated in phantom experiments. TRAFF$$ {T}_{\mathrm{RAFF}} $$ and TgirRAFF$$ {T}_{\mathrm{girRAFF}} $$ parametric maps were acquired at 3T in phantom, the calf muscle, and the knee cartilage of healthy subjects. The relaxation time maps were analyzed for resilience against artificially induced field inhomogeneities and assessed in terms of in vivo reproducibility. Results: Optimized girRAFF preparations yielded improved preparation efficiency (0.95/0.91 simulations/phantom) with respect to RAFF (0.36/0.67 simulations/phantom). TgirRAFF$$ {T}_{\mathrm{girRAFF}} $$ preparations showed in phantom/calf 6.0/4.8 times higher resilience to B0$$ {\mathrm{B}}_0 $$ inhomogeneities than RAFF, and a 4.7/5.3 improved resilience to B1+$$ {\mathrm{B}}_1^{+} $$ inhomogeneities. In the knee cartilage, TgirRAFF$$ {T}_{\mathrm{girRAFF}} $$ (53 ±$$ \pm $$ 14 ms) was higher than TRAFF$$ {T}_{\mathrm{RAFF}} $$ (42 ±$$ \pm $$ 11 ms). Moreover, girRAFF preparations yielded 7.6/4.9 times improved reproducibility across B0$$ {\mathrm{B}}_0 $$/B1+$$ {\mathrm{B}}_1^{+} $$ inhomogeneity conditions, 1.9 times better reproducibility across subjects and 1.2 times across slices compared with RAFF. Dixon‐based fat suppression led to a further 15‐fold improvement in the robustness of girRAFF to inhomogeneities. Conclusions: RAFF pulses display residual sensitivity to off‐resonance and pronounced sensitivity to B1+$$ {\mathrm{B}}_1^{+} $$ inhomogeneities. Optimized girRAFF pulses provide increased robustness and may be an appealing alternative for applications where resilience against field inhomogeneities is required. [ABSTRACT FROM AUTHOR]

To investigate the effect of moderate or heavy slow resistance training on structural and mechanical properties of patellar and Achilles tendons in older men, in vivo. Healthy older men (n = 27) undertook a 12‐week resistance training program (3 times/week) of triceps surae and quadriceps muscle‐tendon complexes. Participants were randomly assigned to either a moderate load of 55% 1RM (O55, n = 13, age: 70.0 ± 4.6 years) or a progressively heavier load from 55% up to 80% 1RM (O80, n = 14, age: 69.8 ± 4.4 years). Tendon morphology was investigated using a 1.5 T MRI scanner. Mechanical properties of the free Achilles tendon (AT) and medial gastrocnemius (MG) aponeurosis, patellar tendon (PT), and deep aponeurosis of the vastus lateralis (VL) muscle were assessed using ultrasound imaging. Both training programs led to an increase in mean CSA of the PT (O55; +2.7%, O80; +1.7%, p = 0.002) and AT (O55; +2.8%, O80; +2.5%, p < 0.001). Force and stress were increased for all the four regions investigated, while stiffness and Young's modulus assessed at a common force level were only increased for the AT and VL aponeurosis. No interaction between group and time was demonstrated for any of the outcomes. No interaction between time and the four tendon sites was observed for any of the outcomes at common force. A supervised short‐term heavy or moderate slow resistance training of equal volume yielded an increase in tendon size and altered mechanical properties of tendinous tissue. [ABSTRACT FROM AUTHOR]

The muscle metaboreflex effect on pulmonary ventilation (V̇E) regulation is more apparent during rhythmic exercise than rest, possibly because this reflex interacts with other mechanisms regulating V̇E during voluntary contractions, such as central command. Therefore, we tested whether one part of central command, the descending component of motor execution (i.e., descending motor drive), and the muscle metaboreflex interact synergistically to regulate V̇E. Thirteen healthy adults (9 men) completed four experiments in random order under isocapnia. The muscle metaboreflex was activated by rhythmic handgrip exercise at 60% maximal voluntary contraction (MVC) force with the dominant hand. Then, the muscle metaboreflex remained active during a 4-min recovery period via postexercise circulatory occlusion (PECO), or it was inactivated, maintaining free blood flow to the dominant upper limb. During the last 2 min of the handgrip exercise recovery, participants either performed rhythmic voluntary plantar flexion with the dominant leg at 30% MVC torque to generate descending motor drive or the dominant leg's calf muscles were involuntarily activated by electrical stimulation at a similar torque level (i.e., without descending motor drive). V̇E increased to a similar level during handgrip exercise in all conditions (≈22 L/min, P = 0.364). PECO maintained V̇E elevated above recovery with free blood flow (≈17 L/min vs. ≈13 L/min, P = 0.009). However, voluntary and involuntary plantar flexion with or without PECO evoked similar V̇E responses (Δ ≈ 4 L/min, P = 0.311). Therefore, an interaction between descending motor drive and muscle metaboreflex is not ubiquitous for V̇E regulation during rhythmic exercise. NEW & NOTEWORTHY: Voluntary (i.e., with descending motor drive) and involuntary (i.e., no descending motor drive) plantar flexion elicited similar ventilatory responses when postexercise circulatory occlusion was or was not used in an upper limb. These results indicate that the descending motor drive component of the central command and the muscle metaboreflex do not interact to regulate pulmonary ventilation during rhythmic exercise, which suggests that a supposed interaction between central command-muscle metaboreflex is more complex than previously thought. [ABSTRACT FROM AUTHOR]

Objectives: Comprehensive evaluation of lower-extremity varicose veins (VVs) in patients with diabetes is crucial for treatment strategizing. The study aims to assess the feasibility of using ferumoxytol-enhanced MR venography (FE-MRV) for lower-extremity venous mapping and the detection of VVs in patients with diabetes. Materials and methods: As part of a phase II clinical trial of a generic brand of ferumoxytol, documented patients with diabetes were enrolled and underwent FE-MRV on a 3-Τ MRI system. Two observers assessed FE-MRV images for image quality, signal intensity ratio (SIR), perforator (PV) diameter, and luminal signal uniformity in deep-to-superficial venous networks with the assessment of intra- and inter-rater reliability. FE-MRV was used to detect lower-extremity VVs. Results: Eleven patients underwent FE-MRV without adverse events. The average image quality, as scored by the two observers who assessed 275 venous segments, was 3.4 ± 0.6. Two observers strongly agreed on image quality (κ = 0.90) and SIR measurements (interclass correlation coefficient [ICC]: 0.72) and had good agreement on PV diameter (ICC: 0.64). FE-MRV revealed uniform luminal signals in deep and saphenous venous networks (0.13 ± 0.05 vs 0.08 ± 0.03). Below-knee segments exhibited a significantly higher heterogeneity index than above-knee (p = 0.039) segments. Superficial VVs were observed in 55% (12/22) of legs in 64% (7/11) of patients. Calf muscle VVs were present in 64% (14/22) of legs in 9 patients. Conclusion: FE-MRV safely and robustly mapped entire lower-extremity venous networks, enabling the detection and pre-treatment evaluation of both superficial, and deep VVs in patients with diabetes. Clinical relevance statement: Ferumoxytol-enhanced magnetic resonance venography offers a "one-stop" imaging strategy for the detection and pre-operative evaluation of both superficial and deep VVs in diabetic patients. Key Points: Diabetic patients with VVs are at a higher risk of ulcer-related complications. FE-MRV allowed rapid and comprehensive visualization of the lower-limb venous networks and abdominopelvic veins in diabetic patients. This technique allowed for the detection of superficial and deep VVs in diabetic patients before the development of severe peripheral artery disease. [ABSTRACT FROM AUTHOR]

Purpose: We tested the hypothesis that heat stress influences the closed-loop cardio-postural control by an increased blood pressure (BP) drop and postural sway. Methods: Fourteen healthy individuals (eight women) performed two orthostatic tests under thermal reference (TC; ~ 24 ºC) and HOT (~ 38 ºC) conditions. The center-of-pressure (COP) displacements and the electromyography (EMG) activity of the calf muscles (medial gastrocnemius and tibialis anterior) were recorded during the initial orthostasis (ORT onset) after the supine-to-stand challenge. At the same period, BP (beat-to-beat) was continuously monitored, and supine-to-stand variations (∆%) were calculated. Sublingual temperature (Tsl) was measured as a surrogate of internal temperature. Results: Tsl increased in HOT compared to TC (TC 36.5 ± 0.3 vs. HOT 36.7 ± 0.3 ºC; p < 0.01). COP distance was greater in HOT compared to TC condition (TC 596.6 ± 242.4 vs. HOT 680.2 ± 249.1 mm; p < 0.01). EMG activity of the gastrocnemius decreased in HOT compared to TC condition (TC 95.5 ± 19.8 vs. HOT 78.4 ± 22.8%mV; p = 0.02). EMG of tibialis did not change between TC and HOT (TC 83.5 ± 42.9 vs. HOT 66.1 ± 31.9% mV; p = 0.29). BP showed a greater fall in HOT compared to TC condition (∆%TC − 24.5 ± 13.2 vs. ∆%HOT − 33.2 ± 20.2%; p = 0.01). Conclusion: Heat stress causes a greater fall in blood pressure and a reduction in musculoskeletal pump activity during orthostatic onset. These effects could be potential mechanisms that underlie augmented postural instability under a heated environment. [ABSTRACT FROM AUTHOR]

This study retrospectively compared the effect of holding the 2022 FIFA World Cup™ (WC) mid-season (season 2022/23) on injury rates and patterns in French Ligue 1 soccer clubs. Epidemiological data in 17 clubs were prospectively recorded by their physicians. Time-loss injuries (injuries leading to a player being unable to fully participate in play over the following 72-hour period) were compared with those reported during a regular season (2021–22). In the WC season, an increase of approximately 23% (training + match-play) was observed for both the total number of injuries and knee, ankle and muscle injuries combined. Incidences for match-play injury overall and for the knee, ankle and muscle regions combined and the hamstrings and calf regions specifically also rose significantly (range: p < 0.05-p < 0.01). These results suggest that injury occurrence and patterns in French L1 soccer clubs were substantially affected during the 2022/23 season when a mid-season WC was held. [ABSTRACT FROM AUTHOR]

Objective: The aim of the study is to evaluate the muscle thickness and walking test in people with hemophilia A and their correlation to joint health and functional impairments. Design: This is a cross-sectional study. Results: Twenty-nine severe/moderate people with hemophilia Awere enrolled. Muscle thickness of quadriceps and medial gastrocnemius was measured using ultrasound. Joint health and functional capacity were assessed using Hemophilia Joint Health Score, Hemophilia Early Arthropathy Detection with Ultrasound, 6-Minute Walking test, Hemophilia Quality of Life Questionnaire for Adults, and Hemophilia Activities List. Quadriceps muscle thickness significantly correlated with Hemophilia Joint Health Score knee, Hemophilia Early Arthropathy Detection with Ultrasound knee, and Hemophilia Activities List. Calf muscle thickness significantly correlated with the Hemophilia Joint Health Score ankle. After adjusted age and body mass index, calf muscle thickness was inversely associated with the Hemophilia Joint Health Score ankle. Six-Minute Walking test was found to significantly correlate with Hemophilia Joint Health Score total, Hemophilia Early Arthropathy Detection with Ultrasound total, Hemophilia Quality of Life Questionnaire for Adults, and Hemophilia Activities List. Conclusions: Muscle thickness and the distance of 6-Minute Walking Test were linked to assessment of joint health, quality of life, and activity participation in people with hemophilia A. Ultrasound measurement of muscle thickness and walking test seem to be useful tools for the assessment of joint health and functional status in people with hemophilia A. [ABSTRACT FROM AUTHOR]

Background While controversy remains as to the relative benefit of operative (OM) versus non-operative management (NOM) of Achilles tendon (AT) ruptures (ATR), few studies have examined the effect on high impact maneuvers such as jumping and hopping. Hypothesis/Purpose The purpose of this study was to determine if functional performance including strength, jumping, and hopping outcomes differed between OM and NOM of acute ATR. The secondary objective was to assess the degree of association between AT morphology and performance outcomes. Study Design Retrospective cohort with a single prospective evaluation. Methods All patients were treated at an institutional secondary care center. Eligible participants (n=12 OM; 12 NOM) who were treated with OM or NOM of ATR within three weeks of injury were evaluated a minimum 20 months following ATR. AT length, thickness and gastrocnemius muscle thickness were assessed with B-mode ultrasound. Isokinetic plantar flexor strength, hop tests and countermovement and drop jumps were completed. Two-way ANOVAS were completed on all tests with unilateral values, independent t-tests were used for bilateral outcomes, and linear regressions were completed to assess the relationship between normalized AT length and performance. Results Affected limb AT was elongated and thickened (p<0.01), gastrocnemius was atrophied (p< 0.01) and angle-specific plantar flexor torque was reduced at 120°/s when measured at 20° plantar flexion (p = 0.028). Single leg drop vertical jump was higher in OM (p = 0.015) with no difference for hop and jump tests. AT length was related to plantar flexor torque but had no relationship with hopping performance. Conclusions Hop test performance was maintained despite plantarflexion weakness, gastrocnemius atrophy, and AT elongation. This may be the result of compensatory movement patterns. AT length holds limited explanatory power in plantar flexor strength, although this relationship should be evaluated further. Level of Evidence Level III [ABSTRACT FROM AUTHOR]

BACKGROUND: Trolley bags have gained popularity among students, but there is limited research comparing them to backpack-style school bags. OBJECTIVE: This study aimed to compare how carrying a backpack versus a trolley bag affects the activity of trunk and lower limb muscles in secondary school students. METHODS: Electromyographic activity was measured in 25 students (13.4±1.1 years) as they walked on level ground and up/down stairs while carrying both types of bags. The activity of the gastrocnemius, tibialis anterior, semitendinosus, rectus femoris, lumbar erector spinae, and rectus abdominis muscles was assessed on both the dominant and non-dominant sides. RESULTS: The study found significantly reduced muscle activation in most of the targeted muscles when walking on level ground with the trolley bag and when going up/down stairs with the backpack. CONCLUSIONS: Lifting a trolley bag depends on the slope of the walking surface and is more efficient on level ground, while carrying a backpack is more efficient when going up and down stairs. Since it is not practical to switch bags when encountering stairs in schools, a bag with a mixed model design incorporating features of both trolley and backpack may be more beneficial and practical for students to use. Students, parents, and teachers should be aware of the injury risks associated with carrying different types of bags. [ABSTRACT FROM AUTHOR]

Charcot-Marie-Tooth disease (CMT) is a hereditary peripheral neuropathy involving approximately 80 pathogenic genes. Whole-exome sequencing (WES) and confirmatory Sanger sequencing analysis was applied to identify the diseasecausing mutations in a Chinese patient with lower limb weakness. We present an 18-year-oldmalewith a 2.5-year history of progressive lower limbweakness and an unsteady gait. Upon admission, a physical examination revealed hands tremulousness, bilateral calf muscle wasting and weakness, pes cavus, and elevated serum creatine kinase (CK) levels. Electromyography demonstrated axonal neuropathy affecting both upper and lower limbs. A de novo heterozygous missense mutation was identified in the MORC2 gene, NM_ 001303256.3: c.1199A>G, NP_001290186.1: p.Gln400Arg. Consequently, these clinical and genetic findings suggested a diagnosis of hereditary peripheral neuropathy, CMT type 2Z. Oral mecobalamin and coenzyme Q10 was initiated as subsequent treatment. Our study firstly reports theMORC2 c.1199A>Gmutation occurring de novo, highlighting its causal association with CMT2Z, and prompting its reclassification as likely pathogenic. Oral mecobalamin and coenzyme Q10 might be a potential treatment approach for early-stage CMT2Z. We recommend genetic testing for CMT patients to identify the genetic etiology, thereby improving clinical management and facilitating genetic counseling. [ABSTRACT FROM AUTHOR]

Background: A given movement requires precise coordination of multiple muscles under the control of center nervous system. However, detailed knowledge about the changing characteristics of neuromuscular control for multi-muscle coordination in post-stroke hemiplegic patients during standing is still lacking. This study aimed to investigate the hemiplegia-linked neuromuscular dysfunction during standing from the perspective of multi-muscle dynamical coordination by utilizing a novel network approach – weighted recurrence network (WRN). Methods: Ten male hemiplegic patients with first-ever stroke and 10 age-matched healthy male adults were instructed to stand on a platform quietly for 30 s with eyes opened and eyes closed, respectively. The WRN was constructed based on the surface electromyography signals of 16 muscles from trunk, hips, thighs and calves. Relevant topological parameters, including clustering coefficient (C) and average shortest path length (L), were extracted to evaluate the dynamical coordination of multiple muscles. A measure of node centrality in network theory, degree of centrality (DC), was innovatively introduced to assess the contribution of single muscle in the multi-muscle dynamical coordination. The standing-related assessment metric, center of pressure (COP), was provided by the platform directly. Results: Results showed that the post-stroke hemiplegic patients stood with remarkably higher similarity of muscle activation and more coupled intermuscular dynamics, characterized by higher C and lower L than the healthy subjects (p < 0.05). The DC values and rankings of back, hip and calf muscles on the affected side were significantly decreased, whereas those on the unaffected side were significantly increased in hemiplegia group compared with the healthy group (p < 0.05). Without visual feedback, subjects exhibited enhanced muscle coordination and increased muscle involvement (p < 0.05). A decrease in C and an increase in L of WRN were observed with decreased COP areas (p < 0.05). Conclusions: These findings revealed that stroke-induced hemiplegia could significantly influence the neuromuscular control, which was manifested as more coupled intermuscular dynamics, abnormal deactivation of muscles on affected side and compensation of muscles on unaffected side from the perspective of multi-muscle coordination. Enhanced multi-muscle dynamical coordination was strongly associated with impaired postural control. This study provides a novel analytical tool for evaluation of neuromuscular dysfunction and specification of responsible muscles for impaired postural control in stroke-induced hemiplegic patients, and could be potentially applied in clinical practice. [ABSTRACT FROM AUTHOR]

Background: Plantar fasciitis (PF) is a common cause of chronic foot pain that leads to functional limitations in individuals. There has been recent research on plantar fasciitis, but no studies have compared the effects of the active release technique and post-isometric relaxation in patients to determine which manual therapy technique improves foot pain and function. Objective: This study aimed to compare the effectiveness of the active release technique and post-isometric relaxation on proximal foot pain and functional status and to assess muscular tightness among patients with traffic police wards and plantar fasciitis. Methods: A quasi-experimental study (pre-test, post-test) was conducted in the Physiotherapy Department of Police Hospital, Gujranwala, Pakistan, between October 2022 and April 2023. We included 30 consecutively aged 25- to 60-year-old symptomatic police wardens diagnosed with planter fasciitis, who complained of pain on walking and standing for more than 3 months and met the inclusion criteria. They were equally assorted into two groups (n = 15 in each group) using convenient sampling. Group A received an active release exercise technique, group B received a post-isometric relaxation technique, and the participants in both groups received a similar baseline treatment protocol that consisted of calf stretching and stretching of the plantar fascia (5 repetitions and holding for 15 s). In the outcome measures, we included the Foot Function Index to assess the function of the foot and the Visual Analog Scale to examine the pain intensity measured during rest. The participants in both groups performed the selective protocol 3 days per week for 3 weeks, and we calculated the results at baseline and on the third day of the third week. We analyzed the data using SPSS software version 24 (IBM Corp., Armonk, NY). We compared within-group differences in the VAS score and FFI using paired t tests and analyzed between-group differences in the VAS score and FFI before and after performing the ART and PIR using independent t tests. Results: The 8-week intervention therapy revealed a demographic age mean and standard deviation of 36.60 ± 6.11 for group A and 35.60 ± 4.85 for group B. Within-group analysis demonstrated a significant decrease in VAS (pain) score following ART intervention (1.80 ± 0.862, p < 0.01) compared to PIR (6.07 ± 0.884). Between-group analysis indicated a significant reduction in FFI (disability) scores for group A (30.33 ± 3.200, p < 0.03) compared to group B (56.93 ± 4.773). Moreover, ART intervention exhibited significant improvement in VAS scores (p < 0.05), with 95% CI [1.49, 2.11]. The mean difference in FFI scores was substantially greater in the ART group (86.00 to 30.33) compared to the PIR group (p > 0.05), suggesting non-significant differences. Conclusion: The active release exercise intervention is more effective than post-isometric relaxation in improving pain and foot function disability in patients with plantar fasciitis. The present study aimed to help physical therapists choose the most efficient manual therapy exercise intervention to improve functional limitations. [ABSTRACT FROM AUTHOR]

Background: Fat infiltration in skeletal muscle is related to declining muscle strength, whereas excess subcutaneous fat is implicated in the development of metabolic diseases. Methods: Using multi-slice axial T2-weighted (T2w) MR images, this retrospective study characterized muscle fat infiltration (MFI) and fat distribution in the lower extremity of 107 subjects (64M/43F, age 11–79 years) with diverse ethnicities (including White, Black, Latino, and Asian subjects). Results: MRI data analysis shows that MFI, evaluated by the relative intensities of the pixel histogram profile in the calf muscle, tends to increase with both age and BMI. However, statistical significance was found only for the age correlation in women (p < 0.002), and the BMI correlation in men (p = 0.04). Sex disparities were also seen in the fat distribution, which was assessed according to subcutaneous fat thickness (SFT) and the fibula bone marrow cross-sectional area (BMA). SFT tends to decrease with age in men (p < 0.01), whereas SFT tends to increase with BMI only in women (p < 0.01). In contrast, BMA tends to increase with age in women (p < 0.01) and with BMI in men (p = 0.04). Additionally, MFI is positively correlated with BMA but not with SFT, suggesting that compromised bone structure may contribute to fat infiltration in the surrounding skeletal muscle. Conclusions: The findings of this study highlight a sex factor affecting MFI and fat distribution, which may offer valuable insights into effective strategies to prevent and treat MFI in women versus men. [ABSTRACT FROM AUTHOR]

Maternal nutrition significantly influences fetal development and postnatal outcomes. This study investigates the impact of maternal overfeeding during mid to late pregnancy on gene expression in the round and sirloin muscles of Hanwoo neonatal calves. Eight cows were assigned to either a control group receiving standard nutrition (100%) or a treated group receiving overnutrition (150%). After birth, tissue samples from the round and sirloin muscles of neonatal calves were collected and subjected to RNA sequencing to assess differentially expressed genes (DEGs). RNA sequencing identified 43 DEGs in round muscle and 15 in sirloin muscle, involving genes related to myogenesis, adipogenesis, and energy regulation. Key genes, including PPARGC1A, THBS1, CD44, JUND, CNN1, ENAH, and RUNX1, were predominantly downregulated. Gene ontology (GO) enrichment analyses revealed terms associated with muscle development, such as "biological regulation," "cellular process," and "response to stimulus." Protein-protein interaction networks highlighted complex interactions among DEGs. Random Forest analysis identified ARC, SLC1A5, and GNPTAB as influential genes for distinguishing between control and treated groups. Overall, maternal overnutrition during mid-to-late pregnancy results in the downregulation of genes involved in muscle development and energy metabolism in neonatal Hanwoo calves. These findings provide insights into the molecular effects of maternal nutrition on muscle development. [ABSTRACT FROM AUTHOR]

Background: Sarcopenia is an aging-related disorder characterized by a loss of muscle mass and function. Calf circumference (CC) is a useful surrogate marker of muscle mass and function. This prospective study was designed to investigate the association between CC and all-cause mortality during a follow-up for 5 years in the Chinese centenarians. Methods: The China Hainan Centenarian Cohort Study (CHCCS) is conducted in 18 cities and counties of Hainan, China. Results: All 231 centenarians had a mean age of 103.03 years. Survival participants had a longer CC and were often living alone compared with others (P<0.05 for all). Multivariate Cox regression models showed that CC was negatively associated with all-cause mortality (P < 0.05 for all). Participants with a longer CC had a lower mortality risk compared with others [Exp(β): 0.918; 95%confidence interval: 0.863–0.977]. Participants with a longer CC had a lower mortality risk whether they were males or females and lived with family members or alone. Conclusion: CC was negatively associated with all-cause mortality and could be an indicator of future mortality among the Chinese centenarians. Further researches should focus on preventing a decline in the CC in order to promote human longevity. [ABSTRACT FROM AUTHOR]

Introduction: This observational study conducted across seven emergency care units compares the efficacy of four D‐dimer detection methods, namely HemosIL D‐dimer HS (HS), HemosIL D‐dimer HS‐500 (HS‐500), VIDAS D‐dimer (VIDAS), and HemosIL AcuStar D‐dimer (ACUSTAR). The primary focus is on patients with a clinical suspicion of deep venous thrombosis (DVT) or pulmonary embolism (PE). Methods: A total of 149 samples were collected from patients with suspected DVT or PE. The confirmation of DVT/PE was based on calf ultrasound or computed tomography‐Angiography. Direct comparisons were made between the different detection methods, considering both their analytical performance and clinical utility. Additionally, the impact of an age‐adjusted cut‐off on the diagnostic accuracy of each method was assessed. Results: The results revealed comparable negative predictive value, sensitivity, and specificity across the methods, with a notable exception of increased specificity for HS compared with HS‐500 (50.8% vs. 41.5%, p = 0.03). Further analysis incorporating an age‐adjusted cut‐off demonstrated a significant improvement in specificity for HS. When using the age‐adjusted cut‐off, HS exhibited a substantial increase in specificity compared with HS‐500 (63.1% vs. 49.2%, p = 0.004) and demonstrated significantly higher specificity compared with VIDAS (63.1% vs. 53.8%, p = 0.04). Conclusion: The study emphasizes the nonuniversal effect of an age‐adjusted cut‐off and discusses the potential necessity for different cut‐off values, particularly in the case of HS‐500. These findings contribute to the understanding of D‐dimer detection methods in the context of DVT and PE, providing insights into their relative performances and the potential optimization through age‐adjusted cut‐offs. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the acute effects of resistance exercise on muscle architecture and tissue organization at rest and during isometric maximum voluntary contraction (iMVC) of the gastrocnemius medialis muscle. In 16 healthy adults (25 ± 3 y), ultrasound scans were captured before (pre), immediately after (post), and 15 min after (post_15) single-leg calf raises during rest and iMVCs. Measurements included muscle thickness (MT), pennation angle (PA), and fascicle length (FL). Spatial frequency analysis (SFA) assessed tissue organization (e.g. peak spatial frequency radius (PSFR), quality factor (Q6)). MT increased significantly from pre to post (+5.7%) and post_15 (+5.6%) at rest. During iMVC, MT and FL increased significantly from pre to post (MT: +8.1%, FL: +14.9%) and post_15 (MT: +5.2%, FL: +10.5%), while PA decreased significantly from pre to post_15 (−10.2%). PSFR and Q6 decreased significantly from pre to post (−7.0-8.2%) and increased from post to post_15 (+10.3-10.6%) at rest, with no significant changes during iMVC. Resistance exercise led to altered muscle architecture for more than 15 min, while SFA parameters reverted to baseline within 15 min. Thus, SFA potentially enables early differentiation of potential physiological alterations in muscle micro-morphology. [ABSTRACT FROM AUTHOR]

Background: Achilles tendon rupture is a common and primary cause of lower limb tendon injuries suffered during sports-related activities. The causes of Achilles tendon rupture include calf muscle and tendon overuse, steroid local injection in tendon, poor tendon quality, and various medical conditions. Historically, acute Achilles tendon rupture was treated conservatively. However, historical techniques are now associated with an increased risk of rerupture. Aim and Objective: To study of the reconstruction of chronic tendoachilles ruptures with the flexor hallucis longus and peroneus brevis. Material and Method: 30 patients aged between 30 and 60 years underwent reconstruction of chronically ruptured tendon Achilles either with flexor hallucis longus or peroneus brevis. Ruptures are due to stumbling in fields, falling from stairs, and some being uneventful. All these patients attended the department of Orthopaedics OPD and tertiary care of SSIMS, Bhilai. The patients were admitted and surgically treated after appropriate counseling and consent. The results were compared with the Quigley scale and Leppilahti scores. Results: Rupture of the Achilles tendon is more common in middle-aged males. Delay in diagnosis is due to a lack of adequate knowledge by the treating physician and a lack of immediate disability for the patient. The Thompson test has high sensitivity and specificity in diagnosis. Complications such as superficial skin infections and wound dehiscence are more common in patients treated with peroneus Peroneus and Sensory disturbance on foot is post operative complication. Conclusion: Flexor hallucis longus is superior to Peroneus brevis because of its anatomical and technical advantages, less incidence of superficial infections, wound dehiscence, and sensory disturbance, and better weight-bearing times and functional recovery. [ABSTRACT FROM AUTHOR]

Background: Previous studies have attempted to determine prognostic factors for predicting the occurrence of noncontact anterior cruciate ligament (ACL) injuries. However, studies on risk factors for noncontact ACL injuries in Asian female soccer players are limited. Purpose: To identify intrinsic risk factors for noncontact ACL injuries among young female Asian soccer players. Study Design: Cohort study; Level of evidence, 2. Methods: This study evaluated 145 female Japanese soccer players for potential risk factors for noncontact ACL injury during the preseason medical assessment. In total, 25 variables were examined—including anthropometric data, joint range of motion, muscle flexibility, muscle strength, and balance measurements. Participants were monitored throughout a single season for noncontact ACL injuries diagnosed by physicians. Results: Noncontact ACL injuries occurred in 13 knees of 13 players (9%). Lower hamstring-to-quadriceps ratio (0.44 ± 0.07 vs 0.50 ± 0.10; P =.04), greater knee extension muscle strength (3.2 ± 0.5 vs 2.7 ± 0.5 N·m/kg; P <.01), and longer playing experience (10.8 ± 3 vs 8.1 ± 4.2 years; P =.02) were significantly associated with new-onset noncontact ACL injuries in young female soccer players. No statistically significant between-group differences were found for any other variables. Conclusion: New-onset noncontact ACL injury in young female soccer players was significantly associated with lower hamstring-to-quadriceps ratio, greater knee extension muscle strength, and longer soccer experience. These findings will help develop strategies for preventing noncontact ACL injuries among female soccer players. [ABSTRACT FROM AUTHOR]

We examined the effect of prolonged tennis playing on lower limb muscles' activity during the execution of first and second tennis serves. Ten male competitive tennis players executed five first and second serves before (pretest) and after (posttest) a 3‐h tennis match. Surface electromyographic (EMG) activity of four lower limb muscles (vastus lateralis, rectus femoris, gastrocnemius lateralis, and soleus muscles) on each leg was recorded along with maximum ball velocity measured by a radar gun and peak vertical forces recorded by a force platform. For the vastus lateralis, gastrocnemius lateralis, and soleus muscles of the left leg as well as the vastus lateralis muscle of the right leg, EMG amplitude decreased from pre‐ to posttests (p ≤ 0.033). These reductions in the EMG signal were generally more pronounced in the first serve (i.e., ranging from −10% to −40%) compared to the second serve (0% to −25%). Maximum ball velocity for both first (159 ± 12 vs. 154 ± 12 km/h) and second (126 ± 20 vs. 125 ± 15 km/h) serves remained unchanged from pre‐ to posttests (p = 0.638) Similarly, peak vertical forces did not differ between pretest and posttest for both first (1.78 ± 0.30 vs. 1.72 ± 0.29 body weight) and second (1.62 ± 0.25 vs. 1.75 ± 0.23 body weight) serves (p = 0.730). In conclusion, a 3‐h tennis match led to decreased activation levels in various leg muscles during serves, particularly in first serves compared to second serves. Despite consistent maximum ball velocity and peak vertical forces, these reductions in EMG signals suggest that skilled tennis players may adopt compensatory strategies after prolonged play. Highlights: A 3‐h tennis match resulted in reduced relative electromyographic (EMG) amplitudes for various knee extensor and plantar flexor muscles on both sides during the serve.Reductions in EMG signals were more prominent in the first serve (−10% to −40%) compared to the second serve (0% to −25%).Despite unchanged maximum ball velocities and peak vertical forces, muscle recruitment adjustments occurred in the vastus lateralis, gastrocnemius lateralis, and soleus muscles in the left leg and the vastus lateralis muscle in the right leg.Understanding changes in lower extremity muscle activation following prolonged play can help players and coaches develop strategies, such as targeted strength and conditioning protocols, to maintain effective serve technique. [ABSTRACT FROM AUTHOR]

Fermented red ginseng (FRG) enhances the bioactivity and bioavailability of ginsenosides, which possess various immunomodulatory, antiaging, anti-obesity, and antidiabetic properties. However, the effects of FRG extract on muscle atrophy and the underlying molecular mechanisms remain unclear. This study aimed to elucidate the effects of FRG extract on muscle atrophy using both in vitro and in vivo models. In vitro experiments used dexamethasone (DEX)-induced C2C12 myotubes to assess cell viability, myotube diameter, and fusion index. In vivo experiments were conducted on hind limb immobilization (HI)-induced mice to evaluate grip strength, muscle mass, and fiber cross-sectional area (CSA) of the gastrocnemius (GAS), quadriceps (QUA), and soleus (SOL) muscles. Molecular mechanisms were investigated through the analysis of key signaling pathways associated with muscle protein synthesis, energy metabolism, and protein degradation. FRG extract treatment enhanced viability of DEX-induced C2C12 myotubes and restored myotube diameter and fusion index. In HI-induced mice, FRG extract improved grip strength, increased muscle mass and CSA of GAS, QUA, and SOL muscles. Mechanistic studies revealed that FRG extract activated the insulin-like growth factor 1/protein kinase B (Akt)/mammalian target of rapamycin signaling pathway, promoted muscle energy metabolism via the sirtuin 1/peroxisome proliferator-activated receptor gamma-coactivator-1α pathway, and inhibited muscle protein degradation by suppressing the forkhead box O3a, muscle ring-finger 1, and F-box protein (Fbx32) signaling pathways. FRG extract shows promise for ameliorating muscle atrophy by modulating key molecular pathways associated with muscle protein synthesis, energy metabolism, and protein degradation, offering insights for future drug development. [ABSTRACT FROM AUTHOR]

Background: Extracorporeal shockwave therapy (ESWT) has been proven beneficial for post-stroke spasticity (PSS) of ankle plantar flexor muscles. This study aims to investigate the dose-response effectiveness of focused-ESWT and the duration of its effect on the treatment of ankle PSS in stroke patients. Methods: In this double-blinded randomized controlled trial, stroke patients diagnosed with PSS in the ankle plantar flexor muscles were randomly assigned to two groups. The experimental group received double-dose ESWT (4000 pulses per session) targeting spastic calf muscles, while the control group received half the dose (2000 pulses per session). Both groups underwent four sessions over two weeks. The outcomes, including modified Ashworth Scale (MAS), modified Tardieu Scale (MTS), passive range of motion (PROM) of the ankle, Timed Up and Go (TUG) Test, Barthel index and strain elastography were evaluated at baseline, 1st, 4th, 12th, and 24th week after ESWT. Results: Within-group analysis revealed significant improvements in MAS, PROM, TUG Test, and Barthel index for the double-dose ESWT group and improvements in Barthel index for the control group. Between-group analysis revealed greater improvements in TUG Test, Barthel Index and strain elastography for the double-dose ESWT group. Generalized estimating equations analysis indicated that the double-dose ESWT group achieved superior outcomes in the TUG Test, Barthel Index, and strain elastography across various time points and groups. Conclusions: Double-dose ESWT showed better functional improvement and elastography compared to the control group. ESWT demonstrated dose-response effectiveness for PSS of ankle-equinus. Trial registration: NCT05878223. [ABSTRACT FROM AUTHOR]

Purpose: Proprioceptive neuromuscular facilitation (PNF) stretching is considered a clinically effective way to enhance muscle properties; however, rare information exists about its effect on muscle flexibility and strength of the patients with stroke. To investigate the efficacy of PNF exercise on lower extremity muscle flexibility and strength after stroke. Methods: Twenty-four... [ABSTRACT FROM AUTHOR]

We present a sequence building block (SBB) that embeds magnetic resonance spectroscopy (MRS) into another sequence on the Siemens VE platform without any custom hardware. This enables dynamic studies such as functional MRS (fMRS), dynamic shimming and frequency correction, and acquisition of navigator images for motion correction. The SBB supports nonlocalised spectroscopy (free induction decay), STimulated Echo Acquisition Mode single voxel spectroscopy, and 1D, 2D and 3D phase‐encoded chemical shift imaging. It can embed 1H or X‐nuclear MRS into a 1H sequence; and 1H‐MRS into an X‐nuclear sequence. We demonstrate integration into the vendor's gradient‐recalled echo sequence. We acquire test data in phantoms with three coils (31P/1H, 13C/1H and 2H/1H) and in two volunteers on a 7‐T Terra MRI scanner. Fifteen lines of code are required to insert the SBB into a sequence. Spectra and images are acquired successfully in all cases in phantoms, and in human abdomen and calf muscle. Phantom comparison of signal‐to‐noise ratio and linewidth showed that the SBB has negligible effects on image and spectral quality, except that it sometimes produces a nuclear Overhauser effect (NOE) signal enhancement for multinuclear applications in line with conventional 1H NOE pulses. Our new SBB embeds MRS into a host imaging or spectroscopy sequence in 15 lines of code. It allows homonuclear and heteronuclear interleaving. The package is available through the standard C2P procedure. We hope this will lower the barrier for entry to studies applying dynamic fMRS and for online motion correction and B0‐shim updating. [ABSTRACT FROM AUTHOR]

As a class of regulatory factors, microRNAs (miRNAs) play an important role in regulating normal muscle development and fat deposition. Muscle and adipose tissues, as major components of the animal organism, are also economically important traits in livestock production. However, the effect of miRNA expression profiles on the development of muscle and adipose tissues in yak is currently unknown. In this study, we performed RNA sequencing (RNA-Seq) on Tianzhu white yak longissimus dorsi muscle tissue obtained from calves (6 months of age, M6, n = 6) and young (30 months of age, M30, n = 6) and adult yak (54 months of age, M54, n = 6) to identify which miRNAs are differentially expressed and to investigate their temporal expression profiles, establishing a regulatory network of miRNAs associated with the development of muscle and adipose. The results showed that 1191 miRNAs and 22061 mRNAs were screened across the three stages, of which the numbers of differentially expressed miRNAs (DE miRNAs) and differentially expressed mRNAs (DE mRNAs) were 225 and 450, respectively. The expression levels of the nine DE miRNAs were confirmed using a reverse transcription quantitative PCR (RT-qPCR) assay, and the trend of the assay results was generally consistent with the trend of the transcriptome profiles. Based on the expression trend, DE miRNAs were categorized into eight different expression patterns. Regarding the expression of DE miRNAs in sub-trends Profile 1 and Profile 2 (p < 0.05), the gene expression patterns were upregulated (87 DE miRNAs). Gene ontology (GO) and Kyoto Encyclopedia of Genes Genomes (KEGG) analyses showed that the identified DE miRNAs and DE mRNAs were enriched in pathway entries associated with muscle and intramuscular fat (IMF) growth and development. On this basis, we constructed a DE miRNA–mRNA interaction network. We found that some DE mRNAs of interest overlapped with miRNA target genes, such as ACSL3, FOXO3, FBXO30, FGFBP4, TSKU, MYH10 (muscle development), ACOX1, FADS2, EIF4E2, SCD1, EL0VL5, and ACACB (intramuscular fat deposition). These results provide a valuable resource for further studies on the molecular mechanisms of muscle tissue development in yak and also lay a foundation for investigating the interactions between genes and miRNAs. [ABSTRACT FROM AUTHOR]

We compared the effects of different weekly calf training sets on muscle size changes. Sixty-one untrained young women performed a calf training program for 6 weeks, 3 d·wk–1 , with differences in resistance training volume. The participants were randomly assigned to one of the three groups: 6-SET, 9-SET, and 12-SET weekly calf training sets. The calf raise exercise was performed in sets of 15–20 repetitions maximum. The muscle thickness measurements of medial gastrocnemius (MG), lateral gastrocnemius (LG), and soleus (SOL) were taken via B-mode ultrasound. We used the sum of the three-muscle thickness as a proxy for the triceps surae (TSSUM). The 12-SET group elicited greater increases than the 6-SET in LG (6-SET=+ 8.1% vs. 12-SET=+ 14.3%; P =0.017), SOL (6-SET=+ 6.7% vs. 12-SET=+ 12.7%; P =0.024), and TSSUM (6-SET=+ 6.9% vs. 12-SET=+ 12.0%; P =0.005), but there was no significant difference in MG changes (6-SET=+ 6.6% vs. 12-SET=+ 9.9%; P =0.067). There were no significant differences when comparing 9-SET vs. 6-SET and 12-SET (P ≥0.099). Although all groups experienced calf muscle hypertrophy, our results suggest that the higher dose range may optimize triceps surae muscle size gains. [ABSTRACT FROM AUTHOR]

Dynamic muscle fatigue during repetitive movements can lead to changes in communication between the central nervous system and peripheral muscles. This study investigated these changes by examining electromyogram (EMG) characteristics from agonist and antagonist muscles during a fatiguing task. Twenty-two healthy male university students (age: 22.92 ± 2.19 years) performed heel raises until fatigue. EMG signals from lateral gastrocnemius (GL) and tibialis anterior (TA) muscles were processed using synchrosqueezed wavelet transform (SST). Root mean square (RMS), mean frequency (MF), power across frequency ranges, wavelet coherence, and co-activation ratio were computed. During the initial 80% of the task, RMS and EMG power increased for both muscles, while MF declined. In the final 20%, GL parameters stabilized, but TA showed significant decreases. Beta and gamma intermuscular coherence increased upon reaching 60% of the task. Alpha coherence and co-activation ratio remained constant. Results suggest that the central nervous system adopts a differentiated control strategy for agonist and antagonist muscles during fatigue progression. Initially, a coordinated "common drive" mechanism enhances both muscle groups' activity. Later, despite continued increases in muscle activity, neural-muscular coupling remains stable. This asynchronous, differentiated control mechanism enhances our understanding of neuromuscular adaptations during fatigue, potentially contributing to the development of more targeted fatigue assessment and management strategies. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of a 10-month neuromuscular training (NMT) intervention on muscle architecture, isometric force production, and stretch-shortening cycle (SSC) function. Thirty-seven girls aged 6-12 years were placed into gymnastics + NMT (gNMT; n = 15), gymnastics only (GYM; n = 10), or maturity-matched control (CON; n = 12) groups. The gNMT group followed a 10-month NMT program in addition to gymnastics training, whereas the GYM group only participated in gymnastics training. Isometric midthigh pull (IMTP) and drop jump (DJ) kinetics were measured, in addition to muscle thickness, fascicle length, and pennation angle of the gastrocnemius medialis at baseline and at 4, 7, and 10 months. A3 x 4 (group x time) repeated-measures ANCOVA (covariate, % predicted adult height) was used to evaluate within-group changes. Significance level was set at p < 0.05. Significant interaction effects were observed in muscle thickness, absolute (PFabs) and relative peak force (PFrel) in the IMTP and various DJ variables. The gNMT group demonstrated improvements in muscle thickness, IMTP PFabs and PFrel, and DJ kinetics, most commonly evidenced from 7 months onward. The GYM group's muscle thickness also significantly improved, accompanied by improvements in some DJ kinetics. The CON group did not experience any desirable changes. Overall, NMT elicited positive changes in muscle thickness, PFabs and PFrel, and SSC function to a greater extent than gymnastics training alone or growth and maturation. As most adaptations took 7 months, longer-term NMT programs should be implemented with youth female gymnasts. [ABSTRACT FROM AUTHOR]

Purpose: Human skeletal muscle has the profound ability to hypertrophy in response to resistance training (RT). However, this has a high energy and protein cost and is presumably mainly restricted to recruited muscles. It remains largely unknown what happens with nonrecruited muscles during RT. This study investigated the volume changes of 17 recruited and 13 nonrecruited muscles during a 10-wk single-joint RT program targeting upper arm and upper leg musculature. Methods: Muscle volume changes were measured by manual or automatic 3D segmentation in 21 RT novices. Subjects ate ad libitum during the study and energy and protein intake were assessed by self-reported diaries. Results: Posttraining, all recruited muscles increased in volume (range: +2.2% to +17.7%, P < 0.05), whereas the nonrecruited adductor magnus (mean: -1.5% ± 3.1%, P = 0.038) and soleus (-2.4%± 2.3%, P = 0.0004) decreased in volume. Net muscle growth (r = 0.453, P = 0.045) and changes in adductor magnus volume (r = 0.450, P = 0.047) were positively associated with protein intake. Changes in total nonrecruited muscle volume (r = 0.469, P = 0.037), adductor magnus (r = 0.640, P = 0.002), adductor longus (r = 0.465, P = 0.039), and soleus muscle volume (r = 0.481, P = 0.032) were positively related to energy intake. When subjects were divided into a HIGH or LOW energy intake group, overall nonrecruited muscle volume (-1.7% ± 2.0%), adductor longus (-5.6% ± 3.7%), adductor magnus (-2.8% ± 2.4%), and soleus volume (-3.7% ± 1.8%) decreased significantly (P < 0.05) in the LOW but not the HIGH group. Conclusions: To our knowledge, this is the first study documenting that some nonrecruited muscles significantly atrophy during a period of RT. Our data therefore suggest muscle mass reallocation, that is, that hypertrophy in recruited muscles takes place at the expense of atrophy in nonrecruited muscles, especially when energy and protein availability are limited. [ABSTRACT FROM AUTHOR]

Muscle hyperemia in exercise is usually the combined result of increased cardiac output and local muscle vasodilation, with the latter reflecting muscle's capacity for increased blood perfusion to support exercise. In this study, we aim to quantify muscle's vasodilation capability with dynamic BOLD imaging. A deoxyhemoglobin-kinetics model is proposed to analyze dynamic BOLD signals acquired during exercise recovery, deriving a hyperemia index (HI) for a muscle group of interest. We demonstrated the method's validity with calf muscles of healthy subjects who performed plantar flexion for muscle stimulation. In a test with exercise load incrementally increasing from 0 to 16 lbs., gastrocnemius HI showed considerable variance among the 4 subjects, but with a consistent trend, i.e. low at light load (e.g. 0–6 lbs) and linearly increasing at heavy load. The high variability among different subjects was confirmed with the other 10 subjects who exercised with a same moderate load of 8 lbs., with coefficient of variance among subjects' medial gastrocnemius 87.8%, lateral gastrocnemius 111.8% and soleus 132.3%. These findings align with the fact that intensive exercise induces high muscle hyperemia, but a comparison among different subjects is hard to make, presumably due to the subjects' different rate of oxygen utilization. For the same 10 subjects who exercised with load of 8 lbs., we also performed dynamic contrast enhanced (DCE) MRI to measure muscle perfusion (F). With a moderate correlation of 0.654, HI and F displayed three distinctive responses of calf muscles: soleus of all the subjects were in the cluster of low F and low HI, and gastrocnemius of most subjects had high F and either low or high HI. This finding suggests that parameter F encapsulates blood flow through vessels of all sizes, but BOLD-derived HI focuses on capillary flow and therefore is a more specific indicator of muscle vasodilation. In conclusion, the proposed hyperemia index has the potential of quantitatively assessing muscle vasodilation induced with exercise. [ABSTRACT FROM AUTHOR]

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A gastrocnemius contracture is a common problem that results in decreased ankle dorsiflexion that contributes to an array of foot and ankle ailments. A common surgical treatment for this condition is a gastrocnemius recession (GR). Many adaptations of the original procedure have been described. Misinterpretations of proper GR procedures have potentially caused confusion when selecting a treatment. This paper proposes to identify errors between the use of GR and gastrocnemius-soleus recession (GSR) procedure techniques in the current literature. A systematic literature review was performed in June 2021, using the PubMed database and select orthopedic texts. Only studies that met the established criteria and either correctly or incorrectly described a GR or GSR procedure were included. After applying exclusion criteria, 108 publications were included. These articles and texts were reviewed for surgical technique and terminology errors in accordance with established parameters. The articles were classified as either: "Correct" or "Incorrect." Of the 108 publications and texts included, 18 articles incorrectly described either a GR or a GSR (16.67%). Ninety articles correctly described either a GR or a GSR (83.33%). The literature supports the use of a GR to treat a gastrocnemius contracture. Inaccurate articles create confusion as to what exactly a GR entails. Sources of ambiguity included terminology, inconsistent anatomical zone definition, and technique selection. Due to this confusion, it is suspected that patient outcomes can be impacted. Postoperative outcomes of GSR patients are worse than GR patients. Further investigation is necessary to determine if performing the incorrect procedure negatively affects patient outcomes. [ABSTRACT FROM AUTHOR]

Repetitive passive movement (RPM) enhances reciprocal inhibition. RPM is more effective when performed rapidly and at wide joint angles. However, patients with limited joint range of motion may not receive the most effective RPM. Therefore, having an alternative method for performing RPM in patients who cannot perform actual exercise due to limited joint motion is necessary. This study investigated the effects of RPM on spinal excitability using a visual kinesthetic illusion. Participants included 17 healthy adults (7 women). Measurements were taken before, during, and immediately after the intervention. We established two intervention conditions: the control condition, in which participants focused their attention forward, and the illusion condition, in which participants watched a video about RPM. F-waves from the tibialis anterior and soleus muscles were measured, and F-wave persistence and F/M amplitude ratios were analyzed. Under the illusion condition, compared with the preintervention condition, the F/M amplitude ratio of the tibialis anterior increased by approximately 44% during the intervention (p < 0.05), whereas the F-wave persistence of the soleus decreased by approximately 23% from the immediate start of the intervention (p < 0.05). This study suggests that a visual kinesthetic illusion can increase the spinal excitability of the tibialis anterior, whereas reciprocal inhibition can decrease the spinal excitability of the soleus. [ABSTRACT FROM AUTHOR]

The standard treatment for patients with confirmed Venous Leg Ulcers (VLUs) is compression therapy to improve the function of the calf muscle pump. There is a significant cohort of patients who are unable to tolerate optimal compression therapy or indeed any level of compression therapy. In addition, there is a cohort of patients who can tolerate compression whose ulcers show little or no evidence of healing. There is a need for ways to further improve calf muscle pump function and to improve venous ulcer healing in these patients. Published data were reviewed on the use of Muscle Pump Activation (MPA) using common peroneal nerve neuromuscular electrical stimulation (NMES) to improve calf muscle pump function. There is physiological evidence that MPA can improve calf muscle pump function and venous return in both control subjects and in patients with venous disease. The use of MPA has also been shown to improve venous flow volume and venous flow velocity on ultrasound scanning in patients with venous disease. MPA has been shown to improve microcirculation in the skin using Laser Doppler and laser Doppler Speckle Contrast Imaging, in both normal subjects as well as in patients with venous disease and VLU. A recent randomized controlled trial of MPA plus compression therapy compared with compression therapy alone, found significantly faster rates of healing with the use of MPA in addition to compression therapy. There are indications for the use of MPA as an adjunctive treatment to enhance calf muscle pump function in patients with VLU:who cannot tolerate compression therapywho can only tolerate suboptimal, low‐level compressionwhose ulcer healing remains slow or stalled with optimal compression. [ABSTRACT FROM AUTHOR]

Background: Distal embolization as the first manifestation of an abdominal aortic aneurysm (AAA) is relatively rare. AAAs presenting with multiple organs embolization are rarer and serious systemic conditions. There are no reports of life-saving outcomes in patients with AAAs presenting with multiple organs embolization prior to surgery. Case presentation: A 78-year-old man presented with right acute lower limb ischemia (ALLI) and ischemic enteritis coexisting with an 83-mm AAA with a large mural thrombus. Although the patient underwent successful revascularization with endovascular treatment for right ALLI, the manifestation of ischemia of the calf muscles and infection forced right above-knee amputation. The patient also presented with ischemic colitis that resolved with conservative treatment. After receiving appropriate medical therapy and rehabilitation, the patient was successfully treated with open aortic repair for the AAA. Conclusion: We successfully performed open aortic surgery for a rare case of AAA presenting with multiple organs embolization. [ABSTRACT FROM AUTHOR]

Background: The majority of studies that explore changes in musculature following resistance training interventions or examine atrophy due to immobilization or sarcopenia use ultrasound imaging. While most studies assume acceptable to excellent reliability, there seems to be unawareness of the existing absolute measurement errors. As early as 1998, methodological research addressed a collective unawareness of the random measurement error and its practical indications. Referring to available methodological approaches, within this work, we point out the limited value of focusing on relative, correlation-based reliability indices for the interpretability in scientific research but also for clinical application by assessing 1,512 muscle thickness values from more than 400 ultrasound images. To account for intra- and inter-day repeatability, data were collected on two consecutive days within four testing sessions. Commonly-stated reliability values (ICC, CV, SEM and MDC) were calculated, while evidence-based agreement analyses were applied to provide the accompanied systematic and random measurement error. Results: While ICCs in the range of 0.832 to 0.998 are in accordance with the available literature, the mean absolute percentage error ranges from 1.34 to 20.38% and the mean systematic bias from 0.78 to 4.01 mm (all p ≤ 0.013), depending on the measurement time points chosen for data processing. Conclusions: In accordance with prior literature, a more cautious interpretation of relative reliability values should be based on included systematic and random absolute measurement scattering. Lastly, this paper discusses the rationale for including different measurement error statistics when determining the validity of pre-post changes, thus, accounting for the certainty of evidence. Key Points: • While reliability of a testing protocol is most often determined via relative reliability indices such as the intraclass correlation coefficient, further reliability values such as the systematic bias and the random error have been described as valuable for results interpretation. • This study used the most frequently employed procedure to determine muscle hypertrophy (ultrasound) as an example linking relative reliability values to absolute measurement errors under special consideration of appropriate calculation models using three scenarios (best case, worst case, stability). • Overall, 504 ultrasound images were examined showing excellent relative reliability, but the corresponding measurement errors suggest that caution must be exercised when interpreting pre-post settings in cases where the measurement error exceeds the expected changes. [ABSTRACT FROM AUTHOR]

Objective: The objective of this investigation is to examine the contribution of key muscle groups in the lower limbs to vertical jumping performance in elite male volleyball players. Specifically, the study focuses on the rectus femoris (RF), vastus lateralis (VL), and lateral gastrocnemius (LG), as well as exploring differences between attack jump and other vertical jump types. Methods: To achieve this, we employed B-mode ultrasound to evaluate the anatomical cross-sectional area (ACSA), muscle thickness (MT), pennation angle (PA), and fascicle length (FL) of the RF, VL, and LG in the participants. Fifteen elite male volleyball players were recruited as participants for this study. Jump heights were measured for four types of vertical jumps: attack jump (AJ), countermovement jump (CMJ), squat jump (SJ), and drop jump (DJ). We conducted regression analyses to assess whether the previously mentioned muscle structures could predict jump performance. Results: Our findings reveal that the muscle structure of the RF does not exhibit any significant correlation with the height of any jump. However, VL-ACSA displays a significant and the most potent predictive effect on jump height for all four jump types (AJ: R2 = 0.32, p = 0.001; CMJ: R2 = 0.37, p = 0.005; SJ: R2 = 0.52, p = 0.001; DJ: R2 = 0.25, p = 0.021). Conversely, LG-FL only demonstrates a significant and stronger predictive effect on AJ jump height (R2 = 0.18, p = 0.009). Combining VL-ACSA, LG-FL, and training age through multiple linear regression analysis resulted in a highly significant model for predicting AJ jump height (F = 13.86, R2 = 0.73). Moreover, the model incorporating VL-ACSA and training age is also important for predicting CMJ, SJ, and DJ jump heights (F = 8.41, R2 = 0.51; F = 13.14, R2 = 0.63; F = 5.95, R2 = 0.41; respectively). Conclusion: The muscle structure indicators in the lower limbs significantly predict jump performance among elite male volleyball players. However, different jump types are influenced by distinct indicators, particularly in the case of AJ, which is associated with LG-FL. This suggests that enhancing LGFL may positively impact AJ ability, thereby emphasizing the importance of specificity in training. To optimize specialized jump performance in volleyball players, practitioners are advised to assess VL-ACSA and LG-FL and incorporate step-up and eccentric strength training targeting the calf muscles to yield considerable benefits. [ABSTRACT FROM AUTHOR]

Background: Rating scales and linear indices of surface electromyography (sEMG) cannot quantify all neuromuscular conditions associated with ankle-foot dysfunction in hemiplegic patients. This study aimed to reveal potential neuromuscular conditions of ankle-foot dysfunction in hemiplegic patients by nonlinear network indices of sEMG. Methods: Fourteen male patients with hemiplegia and 10 age- and sex-matched healthy male adults were recruited and tested in static standing position. The characteristics of the root mean square (RMS), median frequency (MF), and three nonlinear indices, the clustering coefficient (C), the average shortest path length (L), and the degree centrality (DC), of eight groups of muscles in bilateral calves were observed. Results: Compared to those of the control group, the RMS of the medial gastrocnemius (MG), flexor digitorum longus (FDL), and extensor digitorum longus (EDL) on the affected side were significantly lower (P < 0.05), and the RMS of the tibial anterior (TA) and EDL on the unaffected side were significantly higher (P < 0.05). The MF of the EDL on the affected side was significantly higher than that on the control side (P < 0.05). The C of the unaffected side was significantly higher than that of the control group, whereas the L was lower (P < 0.05). Compared to those of the control group, the DC of the TA, EDL, and soleus (SOL) on the unaffected sides were higher (P < 0.05), and the DC of the MG on the affected sides was lower (P < 0.05). Conclusion: The change trends and clinical significance of these three network indices, including C, L, and DC, are not in line with those of the traditional linear indices, the RMS and the MF. The C and L may reflect the degree of synchronous activation of muscles during a certain motor task. The DC might be able to quantitatively assess the degree of muscle involvement and reflect the degree of involvement of a single muscle. Linear and nonlinear indices may reveal more neuromuscular conditions in hemiplegic ankle-foot dysfunction from different aspects. Trial registration: ChiCTR2100055090. [ABSTRACT FROM AUTHOR]

Background: Calf circumference is currently recommended as a case-finding marker for sarcopenia, but its usefulness has not been determined in chronic pain conditions. Therefore, the present study aimed to evaluate the predictive performance of calf circumference in diagnosing sarcopenia in older patients with chronic low back pain. Methods: Ambulatory adult patients aged ≥ 65 years with chronic low back pain were enrolled. A diagnosis of sarcopenia was established based on the criteria outlined by the Asian Working Group for Sarcopenia in 2019. Patient demographics, pain-related factors, clinical factors, and sarcopenia-related measurements were compared between non-sarcopenic and sarcopenic patients. Linear regression analysis was used to evaluate the correlation of calf circumference with muscle mass, strength, and physical performance. Also, a receiver operating characteristic curve analysis for calf circumference in predicting sarcopenia was conducted; and area under the curve (AUC) values, along with their corresponding 95% confidence intervals (CI), were calculated. Results: Data from 592 patients were included in the analysis. Eighty-five patients were diagnosed with sarcopenia (14.3%), 71 of whom had severe sarcopenia (11.9%). A higher prevalence of sarcopenia was observed in female patients (9.0% vs. 16.7%, p = 0.016). After adjusting for age, BMI, and comorbidities, calf circumference correlated positively with muscle mass but not with muscle strength and physical performance. The AUC values for sarcopenia were 0.754 (95% CI = 0.636–0.871, p = 0.001) in males and 0.721 (95% CI = 0.657–0.786, p < 0.001) in females. The cut-offs for calf circumference in predicting sarcopenia were 34 cm (sensitivity 67.1%, specificity 70.6%) in males, and 31 cm (sensitivity 82.5%, specificity 51.5%) in females. Conclusions: Even though sex differences in its predictive value for sarcopenia should be considered, our findings suggest that calf circumference can be used as an indicator for predicting muscle mass and may serve as a potential marker for identifying sarcopenia in older patients with chronic low back pain. [ABSTRACT FROM AUTHOR]

People with Charcot-Marie-Tooth (CMT) disease often undergo foot and ankle surgery, as foot deformities are common and cause a degree of functional limitations impairing quality of life. Surgical approaches are variable and there are no evidence-based guidelines. A multidisciplinary approach involving neurology, physical therapy and orthopaedic surgery is ideal to provide guidance on when to refer for surgical opinion and when to intervene. This review outlines the range of foot deformities associated with CMT, their clinical assessment, and their conservative and surgical and postoperative management. [ABSTRACT FROM AUTHOR]