Search Results (322)

Background/Objectives: Muscular dystrophies (MDs) are progressive neuromuscular disorders in which rehabilitation is central to management, yet conventional physical therapy in children is constrained by motivation, accessibility, and the need to adapt across disease stages. Virtual reality (VR) offers an interactive, adaptable, and home-deliverable alternative, but prior reviews focused narrowly on upper-limb outcomes in Duchenne muscular dystrophy or on motor-learning paradigms. We aimed to evaluate VR-based rehabilitation in children and adolescents with MD across feasibility/adherence, engagement and psychological outcomes, and clinical motor outcomes, and to propose a stage-based conceptual framework. Methods: PubMed, Embase, and Cochrane CENTRAL were searched on 21 April 2026, following PRISMA 2020 (PROSPERO CRD420261380539). Eligible studies enrolled children or adolescents (mean age ≤ 18 years or separable pediatric data) with any MD who received VR/AR/MR/exergame/serious-game rehabilitation. Risk of bias was assessed with RoB 2.0 and ROBINS-I, and certainty with GRADE. Given substantial heterogeneity, findings were synthesized narratively by disease stage. Results: Eight studies (2017–2024; 221 participants) met the inclusion criteria. No serious VR-related adverse events occurred, and feasibility and tolerability were consistently favorable. Engagement and psychological outcomes showed favorable trends, including sustained motivation and reduced perceived fatigue. Clinical motor outcomes were heterogeneous and stage-dependent. Conclusions: The evidence base is limited and clinically heterogeneous, precluding meta-analysis, with Low GRADE certainty for feasibility, safety, and adherence and Very low for the remaining four domains. Key limitations include small sample sizes, substantial clinical and methodological heterogeneity, and only a single advanced-stage study. The findings provisionally support a stage-dependent role for VR-based rehabilitation in pediatric MD: motor training in the ambulatory stage, upper-limb maintenance and interface-adapted training in the transitional stage, and feasibility-, engagement-, and psychological-support applications in advanced disease. Stage-stratified trials with standardized, domain-specific outcomes and explicit virtual-to-real transfer assessment are warranted. Full article

Real-time fatigue classification on resource-constrained edge devices faces three unresolved computational challenges: just-in-time compilation latency spikes that violate the 50 ms inference budget, statistical moment features insensitive to temporal complexity signatures of fatigue, and binary anomaly outputs insufficient for actionable coaching decisions. A synthetic IMU dataset (9 subjects, 540,000 samples, 6 channels at 100 Hz) was generated as a reproducible computational benchmark, with fatigue signatures calibrated to published biomechanical effect sizes (sample entropy $d=+0.77$; permutation entropy $d=+0.38$). We present Safari (Stochastic Adaptive Fitness-Aware Real-time Inference), an end-to-end computational pipeline integrating: a dual-pathway entropy triplet (SampEn, PermEn, SpEn) replacing statistical moments; 16 pre-compiled polyhedral anchor kernels eliminating JIT latency; $O\left({(\Delta W)}^2\right)$-bounded runtime interpolation; subject-specific MaxEnt free-energy anomaly scoring; and a Banister fitness–fatigue adaptive threshold. Safari achieves AUC-ROC = 0.9820 (Monte Carlo 95% CI: 0.9726–0.9886), F1 = 0.8835, four-state accuracy = 83.3%, and worst-case latency = 7.2 ms on a Raspberry Pi 4. Entropy features achieve 1.55× higher discriminability than statistical moments. Safari is a computational framework for real-time fatigue monitoring, contributing a reproducible algorithmic benchmark for edge AI in movement analysis, with real-athlete validation as the recommended next step. Full article

Background: Cancer cachexia and sarcopenia are highly prevalent complications affecting up to 50% of patients with cancer and are associated with increased treatment toxicity, poorer functional outcomes, and reduced survival. Early identification of muscle deterioration during hospitalization remains challenging. Objective: To evaluate the change in dominant-hand handgrip strength between hospital admission and discharge in hospitalized oncology patients. Methods: This prospective longitudinal study will evaluate hospitalized adults with confirmed malignancy and an expected hospital stay of ≥5 days. Daily handgrip strength and sEMG assessments will be performed as exploratory secondary measures to characterize temporal patterns of muscle function during hospitalization. Baseline and discharge evaluations will additionally include bioelectrical impedance analysis, validated patient-reported outcome measures (SARC-F, EORTC QLQ-C30, PSQI), and serum biomarkers related to inflammatory and nutritional status. Linear mixed models will be used to evaluate longitudinal changes and associations between functional, electrophysiological, and biochemical parameters. Expected results: The study aims to characterize trajectories of muscle function decline during hospitalization, identify candidate biomarker signatures for cachexia detection, and evaluate neuromuscular fatigue patterns using sEMG. Conclusions: This protocol proposes a feasible multimodal framework for monitoring skeletal muscle deterioration during acute oncology hospitalization and may inform future interventional strategies targeting cancer-related cachexia and sarcopenia. Full article

Objectives: Knee proprioception is affected by many biomechanical and physiological factors. Often, during training, rehabilitation, or specific sport requirements, weight or pressure is applied to the foot. However, it is not clear if such applications affect knee proprioceptive acuity. This study examined whether the application of an external weight (3 kg) or of pressure (120 mmHg) at a level above the ankle joint would affect knee proprioception in an open kinematic chain movement in resting or fatigue conditions. Methods: Participants included active young men (n = 7) and women (n = 15), aged 21–34 years, without prior knee injury. Women were tested in their follicular phase. An isokinetic dynamometer was used to evaluate knee joint repositioning. Three knee angles were targeted (30°, 45°, 60°) before and after localized muscle fatigue. A three-way ANOVA analysis with repeated measures and one independent variable (gender) was performed. Results: Analysis showed that ankle weight application positively influenced knee joint proprioceptive acuity resulting in an overall reduction in knee joint angular error for both genders, with the “corrective” effect most evident at 45° and 60° knee joint angles (p < 0.05), whether in the rested or fatigued state. The application of pressure however improved knee proprioceptive performance in men (p < 0.05), in both the rest and fatigue states, but not in women (ns tendency). Conclusions: Application of a small weight at the ankle level significantly improved proprioceptive knee joint acuity. These findings may have wider applicability by allowing the development of specific preventive measures towards safeguarding weaker and/or less resilient players. Full article

Prolonged sitting is a common occupational exposure among administrative and office workers and is associated with increased postural muscle stiffness, fatigue, and musculoskeletal discomfort. This study aimed to evaluate whether a dedicated physiotherapeutic training programme can reduce biomechanical indicators of muscle overload in sedentary administrative staff. Forty-five female administrative employees were allocated to an intervention group (n = 22) or a control group (n = 23). The intervention group completed a four-week supervised physiotherapeutic programme comprising three 45 min sessions per week, including stretching, strengthening, and sensorimotor exercises targeting postural muscles. Muscle stiffness was assessed using myotonometry, while muscle fatigue was evaluated with surface electromyography based on median frequency slope analysis. The intervention effect was assessed using ANCOVA, with post-intervention values adjusted for corresponding baseline values. The intervention group showed significant reductions in muscle stiffness and fatigue, particularly in the upper trapezius and thoracic erector spinae, with moderate-to-large effect sizes. These findings indicate that targeted physiotherapeutic training can improve neuromuscular function and fatigue resistance in sedentary workers. Incorporating structured physiotherapeutic exercise into workplace health programmes may support musculoskeletal resilience and reduce the biomechanical consequences of prolonged sitting. Full article

High-intensity 5 km running offers an ideal framework to analyze the organism’s multidimensional responses. Since previous research primarily analyzed isolated aspects of fatigue, this study aimed to examine the integrated acute neuromuscular, metabolic, and perceptual responses to a 5 km run. Twenty-one recreational male runners participated. Pre- and post-race assessments included body composition, blood lactate, m. rectus femoris ultrasound thickness, quadriceps maximal voluntary isometric contraction (MVIC), heart rate, perceived exertion (Borg CR10), and 5 km finish time. Statistical analysis was performed in the Jamovi software, utilizing descriptive statistics, the Shapiro–Wilk test of normality, the Wilcoxon signed-rank test with effect size calculation, and Spearman’s correlation coefficient, at a significance level of p < 0.05. Post-race measurements revealed a significant decrease in quadriceps MVIC (pre: 305 ± 99 N vs. post: 259 ± 88 N; p = 0.002) and an increase in blood lactate (pre: 0.8 ± 0.4 vs. post: 6.9 ± 1.4 mmol/L; p < 0.001), alongside high average heart rates (165 ± 16 bpm). However, ultrasound-assessed muscle architecture remained unchanged. The 5 km run induced pronounced neuromuscular and metabolic fatigue. Unchanged muscle architecture suggests that acute strength decline is primarily mediated by metabolic and neural mechanisms, rather than immediate structural–morphological factors. These findings highlight the value of an integrated assessment approach for understanding acute fatigue responses following high-intensity 5 km running and may contribute to more precise training-load prescription and recovery monitoring in recreational runners. Full article

Although athlete monitoring can quantify training exposure and athlete status with increasing detail, conversion into daily training decisions remains inconsistent. This structured narrative review synthesizes evidence on training load, neuromuscular readiness, recovery, fatigue interpretation, measurement reliability, applied decision-making, and proposes the LOAD-R framework: a systems model linking Load, Organism response, Adaptive state, Decision, and Re-evaluation. A transparent non-PRISMA strategy was used because the aim was conceptual integration and framework development rather than effect-size pooling. Evidence was organized around field-applicable monitoring domains and their decision value. LOAD-R builds on existing monitoring approaches by organizing single indicators, fixed thresholds, and dashboard alerts into an explicit interpretation-to-action sequence. It classifies athlete state into adaptive, functional-overload, underloaded, uncertain, or maladaptive zones, each linked to progress, maintain, modify, deload, or recover decisions. The framework also provides implementation levels and testable predictions. By framing monitoring as adaptive decision support rather than passive data collection, LOAD-R may improve decision consistency, reduce maladaptive training responses, and enhance the practical value of athlete monitoring in applied sport settings. Full article

Fatigue and muscle wasting are common clinical manifestations of inherited and acquired neuromuscular disorders, including peripheral neuropathies, neuromuscular junction disorders, and myopathies. These conditions encompass a wide disease spectrum with variable prognoses, making accurate diagnosis essential for appropriate management. Congenital myasthenic syndromes (CMSs) are rare, inherited disorders characterized by impaired neuromuscular transmission. Although symptoms often begin in infancy or early childhood, later onset during adolescence or adulthood is increasingly recognized. Clinical phenotypes vary according to the underlying molecular defect, but fatigable weakness predominantly affecting axial and proximal limb muscles is a hallmark feature. We report an adolescent male who developed progressive proximal muscle weakness and wasting over several years, resulting in significant functional impairment. Initial evaluation suggested limb–girdle muscular dystrophy. However, comprehensive investigations, including whole-exome sequencing, identified a heterozygous CHRNB1 mutation consistent with postsynaptic CMS. Targeted pharmacological therapy led to clinical improvement. This case highlights the importance of considering CMS in patients presenting with limb–girdle weakness and underscores the value of genetic testing in establishing an accurate diagnosis and guiding treatment. Full article

(1) Background: Physical fatigue, either in short anaerobic exercises or in aerobic ones, affects locomotion patterns. Those effects, if consistently observed, may function as fatigue proxies. The present study focuses on the regularity of the pseudo-periodic acceleration patterns measured by a wearable sensor. Studies during laboratory anaerobic tasks on healthy subjects and on persons with multiple sclerosis during 6 min walking tests demonstrated that regularity decreases with fatigue. This study’s objective is to verify if the gait regularity during an unsupervised endurance aerobic walking task progressively decreases in healthy subjects. (2) Methods: Ten healthy male adults, not competitive recreational athletes, equipped with an accelerometer, participated in a non-competitive 100 km walk in about 24 h. (3) Results: Eight participants took from about 22 to 25 h to complete the task. Two did not finish. The trend of locomotion regularity (on average −6.3%, p < 0.001, effect size 1.41) was negative for all the participants. The gait speed decrease, in all the participants, explained less than 20% of the regularity decrease. Other outcome indices, such as that related to cadence, did not provide unique trends. (4) Conclusions: Regularity decrease is associated with fatigue in submaximal locomotor efforts; due to the experimental group limitations in size and composition, further studies should extend regularity assessments to women, and to persons with neuromuscular disabilities or attending walking rehabilitation. Full article

Resistance training (RT) is commonly used to enhance neuromuscular performance and sprint swimming outcomes. However, the optimal relative load for elite junior swimmers remains unclear. In particular, little is known about whether very low relative loads can elicit meaningful adaptations while minimizing neuromuscular fatigue in athletes exposed to high concurrent training demands. Therefore, the aim of this study was to compare the effects of two land-based RT programs differing only in relative load intensity (40–50% vs. 55–65% 1RM), performed with maximal intended concentric velocity, on strength, jumping ability, and 50 m freestyle swimming performance in elite junior swimmers. Eighteen elite junior swimmers (15.6 ± 0.9 years) from a national high-performance program were randomly assigned to a low-load (40–50% 1RM; n = 9) or moderate-load (55–65% 1RM; n = 9) group. Both groups completed an 8-week RT program (2 sessions·week⁻¹) with identical exercise selection, volume, execution velocity, and in-water training load. Neuromuscular performance (countermovement jump, squat, bench press, and pull-up strength) and swimming performance (50 m freestyle from the starting block and in-water start) were assessed pre- and post-intervention. Both RT protocols improved squat and bench press strength and 50 m freestyle performance, whereas significant improvements in countermovement jump, pull-up strength, and maximal pull-up repetitions were observed only in the low-load group. Significant group × time interactions were found for countermovement jump, maximal number of pull-up repetitions, and 50 m freestyle performance from the starting block, indicating more favorable changes over time in the low-load group. In conclusion, both low- and moderate-load high-velocity RT improved neuromuscular and 50 m freestyle performance outcomes in elite junior swimmers. However, the low-load RT (40–50% 1RM) appeared to provide additional benefits in specific outcomes (i.e., jumping, pull-ups, and 50 m performance from the starting block). These findings suggest that relatively low loads may be a practical alternative to moderate-load RT in high-volume swimming training environments. Full article

Background/Objectives: Baseball pitching injuries associated with fatigue-induced mechanisms may be attributed to change in lower-body power. In this study, a stretch-resistant belt (theorized to increase intra-abdominal pressure) was studied to determine if it influenced countermovement jump (CMJ) power pre- and post-pitching. Methods: Thirteen college athletes participated in three separate, randomized pitching sessions of forty pitches to evaluate the CMJ performance impacts owed to wearing a team-issued baseball belt versus a belt that was configured with the intent to raise intra-abdominal pressure (IAP). The three belt conditions were; (1) the team-issued belt, standard belt (SB), (2) the IAP-configured belt worn at regular length (RIAP), and the IAP-configured belt fastened two inches with the tightest cinch (2IN). Maximum jump heights were measured on a Jumpmat and captured with hands on hips. Data was integrated to compute jump power and the eccentric utilization ratio, being the ratio of a full stretch CMJ to a static CMJ biased to concentric power. Static CMJ testing had pitchers hold the bottom position for 5 s before takeoff. Repeated measures ANOVA with a post hoc Bonferroni correction determined significant differences; subject-specific interactions were identified. Results: Most athletes maintained or improved performance post-pitching with the RIAP with less variability in coordinating stretch-shortening responses. On a group level, RIAP had greater post-pitching CMJ height and power versus 2IN (p < 0.03) and had less CMJ power loss compared to SB and 2IN belt conditions (p < 0.02). IAP was not directly measured, yet this exploratory study provides preliminary evidence that a 5 mm, theoretical IAP design, via a stretch-resistant belt can influence pre- and post-pitching lower-body neuromuscular performance in collegiate pitchers. Conclusions: The RIAP condition showed less performance decline inferring fatigue resistance, preserved max CMJ height, and lessened post-pitch CMJ power loss. Maximal cinching tended to compromise post-pitch lower-body power and inferred the need to individualize the stretch-resistant belt, designed to increase intra-abdominal pressure, for performance and injury protection benefits. Full article

Objectives: Karting imposes high neuromuscular demands on the forearm during dynamic steering, gripping and braking. This study examined whether a single high-velocity, low-amplitude (HVLA) manipulation of the elbow acutely modified surface EMG_RMS amplitude and EMG median frequency responses during standardized isometric forearm testing after simulated karting load, rather than EMG activity during dynamic driving itself. Methods: In this randomized, sham-controlled, within-subject trial, 15 drivers completed a single-session within-participant protocol in which one upper limb was randomly allocated to receive elbow HVLA manipulation (manipulated limb) and the contralateral limb received a standardized sham procedure (sham limb) involving therapist contact and low-grade oscillatory movement without end-range pre-tension or thrust. Drivers completed two 8 min simulated races separated by the allocated manual procedure. Surface electromyography (EMG) from four forearm muscles was collected outside the karting task during standardized laboratory-based isometric forearm contractions at baseline, after race 1, post-intervention, and after race 2. EMG was not recorded during real-time steering, braking, vibration exposure or competitive driving. The extensor carpi radialis (ECR) was specified as the principal muscle of interest because the HVLA technique pre-tensioned the common extensor origin and radial wrist extensors. The primary outcome was ECR mean EMG_RMS amplitude, expressed in µV, across the four measurement time points; the primary statistical test was the condition × time interaction. ECR maximal EMG_RMS amplitude and ECR median frequency were treated as secondary outcomes, whereas ECU, FCR, and FCU outcomes were treated as exploratory anatomical specificity outcomes. Mixed-model ANOVAs compared maximal and mean EMG amplitudes and median frequency between manipulated and sham limbs, treating limb condition and time as repeated within-participant factors. Results: For the primary outcome, ECR mean EMG_RMS amplitude showed a main effect of condition (p = 0.023) and a condition × time interaction (p < 0.001). As a secondary amplitude outcome, ECR maximal EMG_RMS amplitude showed a main effect of time (p = 0.009) and a condition × time interaction (p < 0.001), with higher post-manipulation values in the manipulated limb. No consistent limb-condition effects were found for the other muscles, and EMG median frequency showed only modest time-related changes (p = 0.031) without between-condition differences. Conclusions: A single-elbow manipulation produced short-lived, muscle-specific increases in ECR activation after simulated racing, whereas broader neuromuscular changes were not evident. These findings indicate only transient modulation of ECR surface EMG amplitude in a small sample of screened karting drivers and do not demonstrate improved recovery, neuromuscular efficiency, sport performance, or injury prevention. Because EMG was assessed during standardized isometric contractions rather than during dynamic steering, braking, vibration exposure or competitive racing, the findings should not be interpreted as direct evidence of altered neuromuscular behaviour during actual kart driving. Larger studies including force, performance, clinical, fatigue-specific and dynamic driving EMG outcomes are required. Full article

Aim: Female athletic performance is shaped by the convergence of menstrual-cycle timing, circadian rhythms, fatigue, and ergogenic supplementation; yet no prior study has examined these factors simultaneously in a sport-specific setting. This study investigated the independent and combined effects of acute caffeine ingestion, calendar-based testing window, time of day, and match-induced fatigue on psychophysiological, cognitive, and physical performance in trained female volleyball players. Methods: Thirteen elite eumenorrheic female volleyball players (age: 24.23 ± 4.06 years) completed a randomized, double-blind, placebo-controlled crossover protocol comprising 12 sessions corresponding to all combinations of testing window (menstrual, follicular, luteal), supplementation (caffeine 6 mg·kg⁻¹ vs. placebo), and time of day (08:00 h vs. 18:00 h). Assessments included the Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, Spiegel questionnaire, Profile of Mood States, Hooper Index, Stroop task, Countermovement Jump (CMJ), Modified Agility T-Test (MAT), and Reactive Agility Test (RAT), administered before and after a one-hour simulated match. Results: Significant main effects of testing window, caffeine, time of day, and fatigue state were observed across all outcome domains (all p < 0.05). Caffeine reduced daytime sleepiness (F(1,12) = 23.84, p < 0.001, ηp² = 0.665), enhanced vigor (F(1,12) = 114.10, p < 0.001, ηp² = 0.905), and improved MAT performance (F(1,12) = 33.27, p < 0.001, ηp² = 0.735). The follicular window was associated with superior cognitive, neuromuscular, and mood-related outcomes relative to the menstrual and luteal windows. Exploratory higher-order interactions suggested condition-specific caffeine benefits for MAT, RAT, and CMJ, particularly in afternoon post-fatigue conditions; these patterns require replication in larger samples. Conclusions: Acute caffeine ingestion improved several psychophysiological, cognitive, and neuromuscular outcomes in trained female volleyball players, with effects that varied across calendar-based testing windows, time of day, and fatigue state. Individualized supplementation strategies incorporating cycle timing and circadian context remain investigational; prescriptive recommendations require replication in larger, hormonally verified samples before clinical or applied adoption. Full article

Background: Soccer match play induces substantial mechanical, metabolic, inflammatory, and neuromuscular stress, yet post-match monitoring in applied settings often relies on isolated markers, venous sampling, or limited time points. This observational repeated-measures study aimed to describe whether capillary-derived biomarkers, neuromuscular performance, and perceptual measures showed asynchronous recovery during the first 48 h after a standardised soccer match in elite players. Methods: Twenty-two elite male outfield soccer players completed a standardised 90 min match. Capillary blood biomarkers, countermovement jump (CMJ), 20 m sprint performance, maximal voluntary contraction (MVC), and delayed onset muscle soreness (DOMS) were assessed before the match, immediately post-match, and at 24 and 48 h post-match. Time effects were analysed using repeated-measures mixed-effects models, and associations between biochemical and functional responses were examined descriptively. Results: Match play induced clear but domain-specific disturbances. IL-6 and cortisol rose rapidly immediately post-match, whereas hsCRP, CK, LDH, myoglobin, and DOMS showed delayed peaks during early recovery. CK, LDH, myoglobin, and soreness remained above baseline at 48 h. CMJ and sprint performance were impaired after the match but largely recovered by 48 h, whereas MVC showed its greatest decrement at 24 h. Exploratory associations indicated that larger muscle damage responses tended to co-occur with greater strength and jump decrements and higher soreness, but these analyses were not causal. Conclusions: Recovery after a standardised elite soccer match was multidimensional and non-synchronous across physiological, neuromuscular, and perceptual domains. A capillary-based, multi-domain assessment strategy may provide a feasible descriptive perspective for field-based observation of post-match fatigue. Full article

The objective of this study was to investigate the impact of localized muscle fatigue (LMF) in the hip, knee, and ankle muscle groups on stair ascent biomechanics, with a focus on identifying compensatory mechanisms following fatigue. Twenty-five participants were fatigued using an isokinetic dynamometer to induce unilateral muscle fatigue in the hip extension, knee extension, and ankle plantarflexion muscles through repetitive isokinetic contractions. We collected stair ascent data before fatigue and after three different fatigue protocols, simultaneously collecting kinematic, kinetic, and electromyographic data. The effects of different muscle fatigue conditions on stair ascent performance were assessed using one-way repeated-measures ANOVA. Key findings revealed that hip fatigue narrowed step width and increased ankle dorsiflexion. Knee fatigue reduced knee extensor moments on the fatigued side and increased hip extension moments bilaterally. Ankle fatigue decreased plantar flexion and increased hip extension moments. Electromyographic data confirmed corresponding shifts in muscle activation. Collectively, the results suggest that localized lower-limb fatigue may alter stair ascent biomechanics in a joint-specific manner. The observed changes in joint moments and muscle activation may reflect a bidirectional pattern of inter-joint compensation, with proximal-to-distal or distal-to-proximal adjustments depending on the fatigued joint. These findings suggest that mechanical and neuromuscular demands may be redistributed across lower-limb joints under acute fatigue conditions; however, given that this study was conducted in healthy young males, the relevance of these findings to stair-related instability or fall risk in more vulnerable populations should be examined in future studies. Full article