Search Results (1,042)

This study aims to investigate asymmetries in muscle activation and co-contraction of main lower limb muscles during flamenco Zap-3 footwork with consideration of the footwork speed and dancer proficiency. Twelve flamenco dancers participated, including six professionals and six amateurs. Each participant performed the Zap-3 sequence under three speed conditions: 160 beats per minute (bpm), 180 bpm and the fastest speed level (F). The normalized surface electromyography was recorded in the gastrocnemius medialis (GM), biceps femoris (BF), tibialis anterior (TA) and rectus femoris (RF) in the dominant (DL) and non-dominant leg (NDL). The co-contraction index was also calculated for selected muscle pairs. The results showed that significant asymmetries occurred only in professional dancers and exclusively at the F speed level. Specifically, the value of the GM in the NDL was higher than that of the DL (p < 0.05, d = 1.97); the value of the BF in the DL was higher than that of the NDL (p < 0.05, d = 1.86) and the co-contraction index of BF/RF in the DL was higher than that of the NDL (p < 0.05, d = 1.87). Understanding these asymmetries may help to inform individualized training strategies aimed at optimizing performance and reducing potential risks. Full article

Early rehabilitation is essential for restoring functional recovery in patients with stroke, particularly during the early phase of post-acute care (PAC), or the subacute stage. We aimed to evaluate the effectiveness of a 7-week PAC rehabilitation program in improving muscle strength, physical performance, and functional recovery. A total of 219 inpatients with stroke in the subacute stage were initially recruited from the PAC ward of a regional teaching hospital in Northern Taiwan, with 79 eligible patients—within 1 month of an acute stroke—included in the analysis. The program was delivered 5 days per week, with 3–4 sessions daily (20–30 min each, up to 120 min daily), comprising physical, occupational, and speech–language therapies. Sociodemographic data, muscle strength, physical performance (Berg Balance Scale [BBS], gait speed, and 6-minute walk test [6MWT]), and functional recovery (modified Rankin Scale [mRS], Barthel Index [BI], Instrumental Activities of Daily Living [IADL], and Fugl–Meyer assessment: sensory and upper extremity) were collected at baseline, 3 weeks, and 7 weeks. Generalized estimating equations analyzed program effectiveness. Among the 56 patients (70.9%) who completed the program, significant improvements were observed in the muscle strength of both the affected upper (B = 0.93, p < 0.001) and lower limbs (B = 0.88, p < 0.001), as well as in their corresponding unaffected limbs; in physical performance, including balance (BBS score: B = 9.70, p = 0.003) and gait speed (B = 0.23, p = 0.024); and in functional recovery, including BI (B = 19.5, p < 0.001), IADL (B = 1.48, p < 0.001), and mRS (B = −0.13, p = 0.028). These findings highlight the 7-week PAC rehabilitation program as an effective strategy during the critical recovery phase for patients with stroke. Full article

Background/Objectives: This study aimed to compare the effects of low- and medium-frequency NMES, combined with a standard physical therapy (SPT) program, on functional capacity in critically ill patients. Methods: Fifty-four critically ill patients admitted into Intensive Care Unit (ICU) and on mechanical ventilation participated in this randomized, single-blinded, experimental study. Participants were randomly assigned to a Control group, who received a lower limb SPT program; the Low-frequency NMES group received lower limb SPT + NMES at 100 Hz; and the Medium-frequency NMES group received lower limb SPT + NMES at 100 Hz with a carrier frequency of 2500 Hz. The outcomes, encompassing functional capacity in the hospital, included muscle strength, handgrip strength, functional status, degree of independence for activities of daily living, functional and dynamic mobility, quality of life, and total days hospitalized. Results: Both NMES protocols combined with SPT improved functional capacity compared to the control group. Medium-frequency NMES provided additional benefits on dynamic balance, in the degree of independence to perform activities of daily living and quality of life (all p < 0.001) prior to hospital discharge. It also promoted larger gains on functional status prior to ICU discharge and on knee extension strength (both p < 0.05) prior to intermediate care unit discharge. Medium-frequency NMES also enhanced handgrip strength earlier than low-frequency NMES when compared to the control group. Notably, medium-frequency NMES was the only intervention associated with a significant reduction in total hospital stay duration (p < 0.05). Conclusions: Medium-frequency NMES, along with an SPT program in critically ill patients, showed greater benefits on functional capacity during recovery than low-frequency NMES. (Trial registration: This trial is registered on ClinicalTrials.gov: NCT05287919). Implications for rehabilitation: 1. Medium-frequency NMES may enhance physical functionality and quality of life in critically ill patients with ICU-acquired weakness. 2. Medium-frequency NMES can reduce the number of hospitalization days. 3. NMES combined with SPT represents a feasible and effective option for patients unable to engage in active rehabilitation during critical illness. Full article

In this study, the effects of walking speed on lower limb muscle activity and gait parameters during over-ground walking were investigated in individuals with chronic stroke. Twenty-four patients with chronic stroke participated in a cross-sectional repeated-measures study, walking 20 m at three different speeds: slow (80% of self-selected speed), self-selected, and maximal speed. Surface electromyography was used to measure muscle activity in five paretic-side muscles (rectus femoris, biceps femoris, tibialis anterior, gastrocnemius, and gluteus medius), while gait parameters, including stride length, stance and swing phases, single-limb support time, and the gait asymmetry index were assessed using a triaxial accelerometer. As walking speed increased, activity in the rectus femoris, biceps femoris, and gastrocnemius muscles significantly increased during the stance and swing phases (p < 0.05), whereas the gluteus medius activity tended to decrease. Stride length on the paretic and non-paretic sides significantly increased with faster walking speed (p < 0.05); however, no significant improvements were observed in other gait parameters or gait asymmetry. These findings suggest that although increasing walking speed enhances specific muscle activities, it does not necessarily improve overall gait quality or symmetry. Therefore, rehabilitation programs should incorporate multidimensional gait training that addresses speed and neuromuscular control factors such as balance and proprioception. Full article

Introduction: Hip abductor strength is essential for pelvic stability, lower limb alignment, and injury prevention. Weaknesses of the gluteus medius and minimus contribute to various musculoskeletal conditions. Lateral band walks and monster walks are elastic resistance exercises commonly used to target the hip abductors and external rotators in functional, weight-bearing tasks. Therefore, the aim was to summarize the current evidence on the biomechanics, muscle activation, and clinical applications of lateral and monster band walks. Methods: This narrative review was conducted following the SANRA guideline. A comprehensive literature search was performed across PubMed, Scopus, Web of Science, and SPORTDiscus up to April 2025. Studies on the biomechanics, electromyography, and clinical applications of lateral band walks and monster walks were included, alongside relevant evidence on hip abductor strengthening. Results: A total of 13 studies were included in the review, of which 4 specifically investigated lateral band walk and/or monster walk exercises. Lateral and monster walks elicit moderate to high activation of the gluteus medius and maximus, especially when performed with the band at the ankles or forefeet and in a semi-squat posture. This technique minimizes compensation from the tensor fasciae latae and promotes selective gluteal recruitment. Proper execution requires control of the trunk and pelvis, optimal squat depth, and consistent band tension. Anatomical factors (e.g., femoral torsion), sex differences, and postural variations may influence movement quality and necessitate tailored instruction. Full article

Background: This study investigates differences in muscle co-contraction and peak electromyography (EMG) activity between novice and advanced Taekwondo athletes during consecutive roundhouse (bandal chagui) kicks, examining the influence of body composition and experience level. Methods: Sixteen Taekwondo athletes (12 males, 4 females; mean age: 20.5 ± 4.3 years) were divided into novice (n = 8) and advanced (n = 8) groups. Muscle co-contraction indices and peak EMG activity across 15 consecutive kicks were assessed in key lower limb muscles, including the biceps femoris (BF), lateral gastrocnemius (LG), rectus femoris (RF), soleus (SO), semitendinosus (ST), tibialis anterior (TA), vastus lateralis (VL), and vastus medialis (VM). Results: Advanced athletes exhibited significantly higher co-contraction indices in BF–RF, VM–BF, and SO–TA pairs (p < 0.05) and increased peak EMG trends in the BF and LG (p < 0.05). Novice athletes showed significantly reduced peak EMG increases in the RF, VM, and VL. EMG trends were influenced by body composition, with principal component analysis indicating that higher fat mass and lower muscle mass were associated with greater variations in muscle activation. Conclusions: These findings suggest that advanced athletes refine motor control through increased co-contraction, improving stability and efficiency, while novices exhibit less optimized coordination patterns. This study provides insights into the neuromechanical adaptations associated with expertise development in Taekwondo. Full article

Objectives: Older adults who worry about not being able to stand up from the floor after a fall, reduce their physical activity, which leads to a higher risk of falling. The Backward Chaining Method (BCM) was developed specifically for this population to safely teach and practice the movement sequence required to stand up from the floor. Our aim is to evaluate the effectiveness of using the BCM to teach older adults how to stand up from the floor, and to determine whether this training has an impact on functional mobility, muscle strength, fear of falling, and life-space mobility. Methods: A total of 26 residents of a long-term care facility were randomly allocated to two groups. Residents in the intervention group (IG, n = 13) participated in a seven-week training program to learn how to stand up from the floor with BCM, in addition to the usual care generally offered in long-term care facilities. The participants in the control group (CG, n = 13) received the usual care alone. The primary outcome measure was functional mobility, assessed by the Timed Up and Go test. Secondary outcome measures included functional lower limb strength, grip strength, fear of falling, and life-space mobility. The outcomes were measured at baseline and after the seven-week intervention period. Results: We found no significant between-group differences in functional mobility, lower limb strength and grip strength; however, IG subjects demonstrated significantly lower fear of falling scores, and significantly higher life-space mobility and independent life-space mobility scores compared to CG subjects after the training program. Conclusions: This study demonstrates that the Backward Chaining Method is a feasible, well-tolerated intervention in a long-term care setting and it may have meaningful benefits, particularly in lessening fear of falling and improving life-space mobility and independent life-space mobility when incorporated into the usual physiotherapy interventions. Full article

Appendage autotomy frequently occurs during the cultivation of Exopalaemon carinicauda, which severely impacts its survival and economic benefits. To investigate the molecular mechanism underlying appendage regeneration in E. carinicauda, this study presents a comparative transcriptome analysis on samples from different stages of appendage regeneration in individuals of the same family of E. carinicauda. A total of 6460 differentially expressed genes (DEGs) were identified between the samples collected at 0 h post-autotomy (D0) and those collected at 18 h post-autotomy (D18h). Additionally, 7740 DEGs were identified between D0 and 14 d post-autotomy (D14d), with 3382 DEGs identified between D18h and D14d. Among them, differentially expressed genes such as EcR, RXR, BMP1, and Smad4 are related to muscle growth or molting and may be involved in the regeneration process. qRT-PCR results revealed that EcBMPR2 was expressed at relatively high levels in the gonad and ventral nerve cord tissues and that the highest level of expression was detected in the regenerative basal tissue at 24 h post-autotomy. In situ hybridization results indicated strong signals of this gene in the cells at the wound site at 72 h post-autotomy. Following knockdown of EcBMPR2, the expression levels of both EcBMPR1B and EcSmad1 were significantly downregulated, and long-term interference with the EcBMPR2 gene resulted in a significantly slower appendage regeneration process compared to the control group. When the downstream transcription factor EcSmad1 was knocked down, the two receptor genes EcBMPR2 and EcBMPR1B were downregulated, whereas EcBMP7 was upregulated. After inhibiting the BMP signaling pathway, the degree of cell aggregation at the autotomy site in the experimental group was significantly lower than that in the control group, the wound healing rate was delayed, and the blastema regeneration time was prolonged from 5 d to 7 d. Collectively, these results indicate that the BMP signaling pathway plays a critical role in the early stages of appendage regeneration in E. carinicauda. This study provides important theoretical insights for understanding limb regeneration in crustaceans. Full article

Eccentric muscle actions are integral to human movement, rehabilitation, and performance training due to their characteristic high force output (overload) and low energy cost and perceived exertion. Despite the growing use of eccentric devices, a gap in the research exists exploring multi-muscle activation profiles during multi-joint eccentric-only, isokinetic exercise. This study aimed to quantify and compare surface electromyographic (EMG) activity of four leg muscles—vastus lateralis (VL), tibialis anterior (TA), biceps femoris (BF), and medial gastrocnemius (GM)—during a standardized (isokinetic) submaximal eccentric multi-joint exercise using the Eccentron dynamometer. Eighteen healthy adults performed eccentric exercise at 40% of their maximal eccentric strength. Surface EMG data were analyzed using root mean square (RMS) and integrated EMG (iEMG) variables. Repeated-measures ANOVAs and effect sizes (ES) were used to evaluate within-subject differences across muscles. Results showed significantly greater activation in the VL compared to all other muscles (p < 0.05; and ES of 1.28–3.17 versus all other muscles), with the TA also demonstrating higher activation than the BF (p < 0.05). The BF exhibited the lowest activation, suggesting limited hamstring engagement. These findings highlight the effectiveness of the multi-joint isokinetic eccentric leg press movement (via an Eccentron machine) in targeting the quadriceps and dorsiflexors, while indicating the possible need for supplementary hamstring and plantar flexor exercises when aiming for a comprehensive lower body training routine. This study provides important insights for optimizing eccentric training protocols and rehabilitation strategies. Full article

Background: This study aimed to investigate how barbell type (elastic vs. inelastic) and lifting speed affect postural stability and lower limb muscle activation during the single-leg deadlift (SLDL), a common unilateral exercise in rehabilitation and performance training. Methods: Twenty-seven healthy adults performed SLDLs using both elastic and inelastic barbells under three lifting speeds (normal, fast, and power). Center of pressure (COP) displacement in the anterior–posterior (AP) and medial–lateral (ML) directions and electromyographic (EMG) activity of eight lower limb muscles were measured. Results: COP displacement was significantly lower when using elastic barbells (AP: F = 6.509, p = 0.017, η² = 0.200, ω² = 0.164; ML: F = 9.996, p = 0.004, η² = 0.278, ω² = 0.243). EMG activation was significantly higher for the gluteus medius, biceps femoris, semitendinosus, and gastrocnemius (all p < 0.01), especially under power conditions. Significant interactions between barbell type and speed were found for the gluteus medius (F = 13.737, p < 0.001, η² = 0.346, ω² = 0.176), semitendinosus (F = 6.757, p = 0.002, η² = 0.206, ω² = 0.080), and tibialis anterior (F = 3.617, p = 0.034, η² = 0.122, ω² = 0.029). Conclusions: The findings suggest that elastic barbells improve postural control and enhance neuromuscular activation during the SLDL, particularly at higher speeds. These results support the integration of elastic resistance in dynamic balance and injury prevention programs. Full article

Botulinum neurotoxin-A (BoNT-A) injections are effective in reducing focal limb spasticity; however, their impact on strength and active function needs to be established. This review was a secondary analysis aimed at evaluating changes to active function in the context of muscle strength changes following BoNT-A intramuscular injection for adult upper and lower limb spasticity. The original review searched eight databases (CINAHL, Cochrane Central Register of Controlled Trials (CENTRAL), Embase, Google Scholar, MEDLINE, PEDro, PubMed, Web of Science) and was conducted with methodology that followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines as described in section 6.2 of Gill et al. For this secondary analysis, no databases were searched; only further data were extracted. The current and preceding review were registered in the Prospective Register of Systematic Reviews (PROSPERO: CRD42022315241). Twenty studies were screened for inclusion, and three studies were excluded because active function was not assessed in all participants. Seventeen studies (677 participants) met the inclusion criteria for analysis. Quality was examined using the PEDro scale and modified Downs and Black checklist and rated as fair to good. Pre- and post-BoNT-A injection strength (agonist, antagonist, and global), active function (activity), participation, and quality-of-life outcomes at short-, mid-, and long-term time points were extracted and analysed. Significant heterogeneity and limited responsiveness in strength and active function outcome measures limited the ability to determine whether changes in strength mediate an effect on active function. Further, variability in BoNT-A type and dose, adjunctive therapies provided, and variability in reporting limited analyses. Overall, no clear relationship existed between the change in muscle strength and active function following BoNT-A injections to the upper and lower limbs for focal spasticity in adult-onset neurological conditions. Full article

Objective: The objective of the study was to investigate the relationship between the level of physical activity and body composition, and the levels of motor skills and strength in overweight and obese men. Methods: The research involved 64 men. Body composition, physical activity, motor control, Motor Control Test (MCT), and strength variables were evaluated. Body composition was assessed by DXA, and the participants were classified into two groups according to the percentage of total fat mass: greater and less than 27.65%. Physical activity was assessed using accelerometry, and motor control was measured with posturography, which provided a composite score of motor performance and postural control effectiveness. Strength was assessed using hand, leg, and back dynamometers. Results: The participants with a higher percentage of body fat had a lower DSI (Dynamic Strength Index) (p < 0.001) and significantly reduced PAL (physical activity level) and energy expenditure (p < 0.001). No significant differences were found in the muscle strength of the upper limbs (p = 0.06) and lower limbs (p = 0.419). With regard to MCT, there was a significant difference between groups in the backward direction (p = 0.041), with the group with the highest percentage of body fat showing lower values. Conclusions: Individuals with a higher percentage of body fat tend to have lower levels of strength, physical activity, and energy expenditure, which can lead to impaired balance. The findings highlight the need for targeted interventions to improve body composition and levels of strength and physical activity, with a positive impact on general health and quality of life. Emphasis should be placed on improving physical activity levels in male individuals with a higher percentage of fat mass to improve their body composition and dynamic strength levels, which are beneficial to life, particularly to help improve postural control. Full article

The objective of this study was to investigate the temporal effectiveness of repetitive peripheral magnetic stimulation (rPMS) on lower-limb motor skill performance in individuals with chronic stroke. In this sham-controlled crossover study, we hypothesized that individuals with stroke who received rPMS would demonstrate improved motor skill performance after the stimulation and maintain this enhanced performance at 30 and 60 min after the stimulation. Sixteen participants performed a visuomotor ankle-tracking task at multiple time points following either rPMS or sham stimulation. rPMS, delivered to the tibialis anterior muscle, did not result in statistically significant changes in spatiotemporal (p = 0.725) or spatial error (p = 0.566) metrics at any post-stimulation time point. These findings suggest that a single session of rPMS does not lead to measurable improvements in lower-limb motor skill performance in individuals with stroke, underscoring the need to refine stimulation parameters and target populations in future protocols. Full article

Background: Soccer performance is largely dependent on high-intensity, unilateral actions such as sprints, jumps, and changes of direction. These demands can lead to strength and power differences between limbs, highlighting the importance of individualised assessment in professional players. Rotational inertial devices offer a valuable method to evaluate and train these mechanical variables separately for each leg. The aim of this study was twofold: (a) to characterise the mechanical variables derived from several lower-body strength exercises performed on rotational inertial devices, all targeting the same muscle group; and (b) to compare the mechanical variables between the dominant and non-dominant leg for each exercise. Methods: Twenty-six male professional soccer players (age = 26.3 ± 5.1 years; height = 182.3 ± 0.6 cm; weight = 75.9 ± 5.9 kg; body mass index = 22.8 ± 1.1 kg/m²; fat mass percentage = 9.1 ± 0.6%; fat-free mass = 68.8 ± 5.3 kg), all belonging to the same professional Belgian team, voluntarily participated in this study. The players completed a single assessment session consisting of six unilateral exercises (i.e., quadriceps hip, hamstring knee, adductor, quadriceps knee, hamstring hip, and abductor). For each exercise, they performed two sets of eight repetitions with each leg (i.e., dominant and non-dominant) in a randomised order. Results: The quadriceps hip exercise resulted in higher mechanical values compared to the quadriceps knee exercise in both limbs (p < 0.004). Similarly, the hamstring hip exercise produced greater values across all variables and limbs (p < 0.004), except for peak force, where the hamstring knee exercise exhibited higher values (p < 0.004). The adductor exercise showed higher peak force values for the dominant limb (p < 0.004). The between-limb comparison revealed differences only in the abductor exercise (p < 0.004). Conclusions: These findings suggest the necessity of prioritising movement selection based on targeted outcomes, although it should be considered that the differences between limb differences are very limited. Full article

Echovirus 18, a member of the B group of enteroviruses, is a significant etiological agent of aseptic meningitis and viral encephalitis in children. In this study, we investigated the pathogenicity of E18 by establishing a mouse infection model after comparing various mouse strains and injection methods. Two-day-old IFNAR1 knockout mice infected with clinical isolates of E18 exhibited symptoms such as lethargy, hind limb paralysis, and even mortality. Similarly, some two-day-old C57BL/6J mice displayed comparable symptoms; however, the incidence was lower than that observed in IFNAR1 knockout mice. No similar symptoms were noted in any Balb/c mice. Significant pathological changes were observed in skeletal muscle, brain tissue, and other organs of symptomatic mice; among these tissues, skeletal muscle demonstrated the highest viral load. The established infection model using two-day-old IFNAR1 knockout mice provides valuable insights into further investigations regarding its pathological injury mechanisms as well as the protective effects conferred by antibodies. Full article