Lower Limb Muscle Research Articles

Effect of a Sensorimotor Training Program for Aerial Maneuvers in Junior Surfers

The purpose of this study was to examine the impact of a sensorimotor training program on maximum ankle dorsiflexion (ankle DF), coordination, dynamic balance and postural control, and lower-limb muscle power, in competitive junior surfers, and its relation to parameters of sensorimotor control required to perform aerial maneuvers. Twelve junior competitive surfers followed a 7-week sensorimotor training program, being assessed pre- and post-program with the knee-to-wall test (KW), Y-Balance test—lower quarter (YBT-LQ), and the countermovement jump test (CMJ). Post-training assessment revealed positive effects on the KW (ankle DF) distance, which increased approximately 2 cm (p < 0.001) for both ankles, and all scores for the YTB-LQ (coordination, dynamic balance, and postural control) variables increased, being significant (p < 0.005) for some reach distances (YBT-LQ—Anterior Left, YBT-LQ—Postero-medial Left, and YTB-LQ Anterior Right). YBT-LQ Anterior Reach Asymmetry also improved by decreasing 1.62 cm (p < 0.001) and the CMJ height (lower limb muscle power) increased 2.89 cm (p < 0.001). The training program proved to effectively enhance parameters of physical performance for this sample, including ankle DF, coordination, dynamic balance, postural control, and lower limb muscle power. This tailored-made task approach can help to optimize surfing performance capabilities and contribute to reducing the risk of injuries while performing aerials.

Mazor X robot-assisted upper and lower cervical pedicle screw fixation: a case report and literature review

BackgroundManual placement of cervical pedicle screws is risky, and robot-assisted placement of atlantoaxial pedicle screws has not been reported.Case reportWe describe a 74-year-old female patient with atlantoaxial fracture and dislocation combined with spinal cord injury caused by a car accident. The left lower limb muscle strength was grade 0, the right upper limb muscle strength was grade 1, and the right lower limb muscle strength was grade 2. Loss of sensation below the clavicle level, decreased superficial sensation in the extremities, loss of deep sensation in the left lower extremity, and incontinence were observed. We successfully placed atlas pedicle screws with the assistance of the Mazor X robot. One week after the operation, radiological imaging revealed that the reduction effect was good, the placement of the pedicle screws was satisfactory, the left upper limb and left lower limb muscle strength was level 2, the right upper limb and the muscle strength of the right lower limb were grade 3, and the sensory function was partially restored. No complications related to screw placement were found at the 3-month postoperative follow-up.ConclusionsMazor X robot-assisted descending pedicle screw fixation of the atlas is feasible and safe.

Artificial intelligence-based analysis of lower limb muscle mass and fatty degeneration in patients with knee osteoarthritis and its correlation with Knee Society Score.

Lower-limb muscle mass reduction and fatty degeneration develop in patients with knee osteoarthritis (KOA) and could affect their symptoms, satisfaction, expectation and functional activities. The Knee Society Scoring System (KSS) includes patient reported outcome measures, which is widely used to evaluate the status of knee function of KOA. This study aimed to clarify how muscle mass and fatty degeneration of the lower limb correlate with the KSS in patients with KOA. This study included 43 patients with end-stage KOA, including nine males and 34 females. Computed tomography (CT) images of the lower limb obtained for the planning of total knee arthroplasty were utilized. Ten muscle groups were segmented using our artificial-intelligence-based methods. Muscle volume was standardized by dividing by their height squared. The mean CT value for each muscle group was calculated as an index of fatty degeneration. Bivariate analysis between muscle volume or CT values and KSS was performed using Spearman's rank correlation test. Multiple regression analysis was performed, and statistical significance was set at p < 0.05. Bivariate analysis showed that the functional activity score was significantly correlated with the mean CT value of all muscle groups except the adductors and iliopsoas. Multiple regression analysis revealed that the functional activities score was significantly associated with the mean CT values of the gluteus medius and minimus muscles and the anterior and lateral compartments of the lower leg (β = 0.42, p = 0.01; β = 0.33, p = 0.038; and β = 0.37, p = 0.014, respectively). Fatty degeneration, rather than muscle mass, in the lower-limb muscles was significantly associated with functional activities score of the KSS in patients with end-stage KOA. Notably, the gluteus medius and minimus and the anterior and lateral compartments of the lower leg are important muscles associated with functional activities.

A wearable hip exoskeleton for anaerobic exercise in healthy adults

Guidelines encouraging social distancing, limited outings, and remote work due to COVID-19 have increased sedentary periods and reduced levels of physical activity. These habits increase the risk of metabolic diseases, obesity, cardiovascular disease, and diabetes mellitus. The World Health Organization recommends muscle-strengthening exercises as well as regular physical activity to promote overall health. This study investigates the effect of a wearable hip exoskeleton on muscle activity and heart rate during anaerobic exercise in 40 healthy adults (mean age of 40.00 ± 11.51 years; n = 20 females). Bot Fit, a wearable hip-type robotic exoskeleton, was developed by Samsung Electronics Co., Ltd. (Suwon, Republic of Korea) to enhance the effects of both aerobic and anaerobic exercise. All study participants performed a fitness exercise protocol, including knee-ups, good mornings, squats, mountain climbs, kick-backs, reverse lunges, and split jacks, with and without a Bot Fit. To evaluate the effect of anaerobic exercise with the Bot Fit, muscle activity and heart rate were measured during fitness exercises with and without a Bot Fit. Measured muscles were the rectus abdominis (RA), erector spinae (ES), rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF), tibialis anterior (TA), gastrocnemius medialis (GCM), and gluteus maximus (GM). During anaerobic exercises with the Bot Fit, there was a significant increase in muscle activity compared to exercising without the Bot Fit. Muscle activity increased significantly in the RA, RF, VL, BF and TA muscles during knee-ups; in the ES, BF, and GM during good mornings; in the RF, VL, VM, BF, and GM during squats; in RA, RF, VL, VM, and GM during mountain climbs; in the RA and BF during kick-backs; in the RF, BF, and GCM during reverse lunges; and in the RF and VL during split jacks (p < 0.05). Heart rates showed a statistically significant increase during good mornings, mountain climbs, and reverse lunge exercises while wearing the Bot Fit (p < 0.05). This study demonstrated that anaerobic exercises by healthy adults using a Bot Fit led to enhanced activation of abdominal and lower-limb muscles as well as an improved heart rate, maximizing the effect of anaerobic exercise compared with the same exercise protocol without a Bot Fit. This suggests that use of a Bot Fit can increase the effectiveness of anaerobic exercise in healthy adults.

Frequency-dependent effects of superimposed NMES on spinal excitability in upper and lower limb muscles

Superimposing neuromuscular electrical stimulation (NMES) on voluntary contractions has proven to be highly effective for improving muscle strength and performance. These improvements might involve specific adaptations occurring at cortical and spinal level. The effects of NMES on corticospinal activation seem to be frequency dependent and differ between upper and lower limb muscles. The aim of this study was to investigate acute responses in spinal excitability, as measured by H-reflex amplitude of flexor carpi radialis (FCR) and soleus (SOL) muscles, after NMES superimposed on voluntary contractions (NMES + ISO) at two different pulse frequencies (40 and 80 Hz). Conditions involved fifteen intermittent contractions at submaximal level. Before and after each condition, H-reflexes were elicited in FCR and SOL muscles.H-reflex amplitudes increased in FCR and SOL following both NMES + ISO at 40 and 80 Hz. The potentiation of the H-reflex was greater following the 40 Hz condition compared to 80 Hz, although no differences between muscles emerged.These findings indicated that superimposing NMES has an excitatory effect on spinal motoneurons in both upper and lower limb muscles with an overall greater response after low frequency NMES. Such facilitation could be associated to enhanced somatosensory stimuli conjunctly with higher supraspinal downward commands.

The Impact of Fu’s Subcutaneous Needling on Lower Limb Muscle Stiffness in Knee Osteoarthritis Patients: Study Protocol for a Pilot Randomized Controlled Trial [Response to Letter

The Impact of Fu’s Subcutaneous Needling on Lower Limb Muscle Stiffness in Knee Osteoarthritis Patients: Study Protocol for a Pilot Randomized Controlled Trial [Response to Letter

Comprehensive corrective exercise program improves ankle function in female athletes with limited weight-bearing ankle dorsiflexion: A randomized controlled trial.

Limited ankle dorsiflexion range of motion is one of the most important risk factors for lower limb injury, which changes the biomechanics and the neuromuscular control of the lower limb muscles. This study aims to test the effectiveness of a comprehensive corrective exercise program (CCEP) on the range of motion, proprioception, dynamic balance, and muscle activation in female athletes with limited weight-bearing lunge ankle dorsiflexion range of motion. 30 female athletes aged 15 to 25 years with dorsiflexion under 34° were randomized to two groups. The intervention group (n = 15) received eight weeks of CCEP including soft tissue mobilization, joint mobilization, stretching, and strengthening, and the control (n = 15) group did not receive any intervention. range of motion, proprioception, dynamic balance, and muscle activation were assessed before and after the intervention. The training group showed clinically acceptable and statistically significant changes in ankle dorsiflexion range of motion (ES = 0.714), balance (ES = 0.423), and proprioception (ES = 0.253; P < 0.05). There were significant changes in the activity of the tibialis anterior and soleus muscles in the dynamic overhead squat test (descending and ascending phases) and the activity of the medial gastrocnemius in the descending phase decreased significantly (P < 0.05). No significant change was observed in the activity of the peroneus longus muscle (P > 0.05). The findings show that CCEP appears to be beneficial in increasing dorsiflexion range of motion, proprioception, balance, and decreasing ankle muscle activity among individuals with limited ankle dorsiflexion. Improving the dorsiflexion range of motion may be promising for reducing ankle sprain injury.

Analysis of anticipatory and compensatory postural adjustment in women of different age groups using surface electromyography.

Postural balance is crucial for daily activities, relying on the coordination of sensory systems. Balance impairment, common in the elderly, is a leading cause of mortality in this population. To analyze balance, methods like postural adjustment analysis using electromyography (EMG) have been developed. With age, women tend to experience reduced mobility and greater muscle loss compared to men. However, few studies have focused on postural adjustments in women of different ages using EMG of the lower limbs during laterolateral and anteroposterior movements. This gap could reveal a decrease in muscle activation time with aging, as activation time is vital for postural adjustments. This study aimed to analyze muscle activation times in women of different ages during postural adjustments. Thirty women were divided into two groups: young and older women. A controlled biaxial force platform was used for static and dynamic balance tests while recording lower limb muscle activity using EMG. Data analysis focused on identifying muscle activation points and analyzing postural adjustment times. Results showed significant differences in muscle activation times between the two groups across various muscles and platform tilt conditions. Younger women had longer muscle activation times than older women, particularly during laterolateral platform inclinations. In anteroposterior movements, older women exhibited longer activation times compared to their laterolateral performance, with fewer differences between the groups. Overall, older women had shorter muscle activation times than younger women, suggesting a potential indicator of imbalance and increased fall risk.

Comparative effects of cognitive and instability resistance training versus instability resistance training on balance and cognition in elderly women

This study investigates the effects of integrated instability resistance training and cognitive training (IRCT) versus isolated instability resistance training (IRT) on balance, gait, muscle strength, and cognitive functions in elderly women.This randomized controlled trial included 36 participants, with 18 in the IRCT group and 18 in the IRT group. The sample size was estimated to achieve a statistical power of 0.95 with a large effect size (0.40; n = 12 each group). The closed-eye single-leg stand test was measured for static balance, the closed-eye stepping test, and the Timed Up and Go Test (TUGT) were measured for dynamic balance. Dual-task balance was assessed by combining the TUGT with cognitive tasks (TUGT-C) and motor tasks (TUGT-M). Gait performance was evaluated using a gait function system. Lower limb muscle strength was measured with the 30-Second Chair Stand Test. Cognitive function was assessed through the Trail Making Test (TMT), Digit Span Test (DST), Stroop Color and Word Test (Stroop), and Digit Symbol Substitution Test (DSST). Results IRCT group showed better improvements in both cognitive (p < 0.001) and motor (p = 0.812 for baseline; p < 0.001 for post-intervention) dual-task abilities, IRCT also experienced better enhancement in certain cognitive functions, particularly in the TMT (p = 0.001) and DSST (p = 0.022) compared to the IRT group. Both groups demonstrated enhancements in walking abilities as shown on selective markers of the gait performance test (p < 0.05) and leg muscle strength via 30-Second Chair (p < 0.001 for time main effect). These results suggest that combining cognitive exercises with physical training more effectively addresses the complex challenges associated with aging in women. The study highlights the potential of comprehensive training approaches in boosting health and quality of life for the elderly, with implications for developing tailored exercise programs focused on reducing fall risks and enhancing quality of life in this population.

Fatigue-induced alterations in force production, trajectory and performance in alpine skiing

ABSTRACT In giant slalom, the ability to apply a high amount of force in the radial direction is essential for performance. A race is characterized by repeated turns performed at high velocity, potentially inducing fatigue. Therefore, this study aimed to assess the effect of fatigue on performance, trajectory characteristics, and force production capacities onto the snow. Twelve skiers ran a 4-turn section with (FATIGUE) and without pre-induced fatigue (CONTROL). Knee extensor maximal voluntary contraction (MVC) was performed before the experiment and after both conditions. Section time, energy dissipation, path length, total force output, force application effectiveness, and EMG activity of the main lower-limb muscles were compared between conditions. Multiple linear regressions were used to understand whether interindividual variability in the kinematic, kinetic and EMG between conditions explains variability in performance changes with fatigue. MVC was lower after FATIGUE (−19.1 ± 6.4%, p < 0.001) but did not change after CONTROL. FATIGUE was associated with longer section times (+0.21 ± 0.11 s, p < 0.001), energy dissipation (−0.78 ± 1.05 J.s.kg.m−1, p = 0.026), path length (+1.1 ± 1.6 m, p = 0.033) and lower force application effectiveness (−0.1 ± 0.1, p = 0.017). This study experimentally demonstrates that fatigue in giant slalom results in lower force application effectiveness, inducing over-dissipation of mechanical energy and longer path length, leading to lower performance.

Evaluation of the lower limb and trunk muscles’ electromyographic activity during different squat techniques

Squatting is a widely used exercise in rehabilitation programs for strength and stability gain. However, little is known about muscle activation in variations of squat exercises. The purpose of this study was to compare the muscle activation of the vastus lateralis (VL), rectus femoris (RF), gluteus medius (GM), long fibular (FL), and erector spinae (EE) during traditional squatting compared to variations of unipodal squatting. Twenty physically active men (age= 21± 2 years, height =1.78± 0.05 m, mass = 84.5± 9.9 Kg) participated in this study. Muscle activation were extracted from electromyography of the rectus femoris, vastus lateralis, fibularis longus, gluteus medius and erector spinae during five exercises: traditional squat, bulgarian squat, single leg leaning forward squat, single leg leaning backward squat and lateral step up. The muscle activations were compared between exercises. Muscle activation in all unipodal squat without foot support exercises was considerably higher than that of traditional squatting (p&lt;0.001). The similar pattern in the EMG activity that was recorded for unilateral squat without foot support (p &gt;0.05). In conclusion, the unilateral squat without foot support exercises are appropriate for facilitating the muscle activity of the muscles of the lower limb and trunk.

An observational study of lower limb muscle imbalance assessment and gait analysis of badminton players

PurposeThe imbalance of muscle strength indicators has a negative impact on players. Lower limb muscle imbalance can cause gait abnormalities and increase the risk of muscle injury or decreased performance in significantly asymmetrical situations. This study aims to assess the lower limb muscle imbalance and gait feature between the dominant and non-dominant sides of badminton players and the associations between the two variables.MethodsThe study included 15 badminton players with years of training experience. Muscle strength and gait parameters were obtained from isokinetic muscle strength testing and plantar pressure analysis systems. The symmetry index was calculated based on formulas such as plantar pressure distribution and percentage of plantar contact area.ResultsIn the isokinetic muscle strength test, significant differences were found in bilateral knee flexors’ average power and total work at 60°/s angular speed. The hamstring to quadriceps ratio (H/Q) range of knee joints of the dominant and non-dominant sides is 0.63–0.74 at low speed, while the H/Q range is 0.81–0.88 at fast speed. The H/Q of bilateral knees increases with increasing angular velocity. As the angular velocity increases, the peak torque to body weight ratio (PT/BW) of the participants’ bilateral knee flexors and extensors shows a decreasing trend. The asymmetry score of H/Q at 180°/s angular speed is positively related with step time and stance time. There are varying degrees of differences in gait staging parameters, plantar pressure in each area, plantar contact area, and symmetry index between the dominant and non-dominant sides of badminton players when walking.ConclusionBadminton players have weaker flexors of the knee joint, imbalanced muscle strength in flexors and extensors, decreased lower limb stability, and a risk of knee joint injury on the non-dominant side. The bending and stretching strength of the knee joint on the dominant side of the players is greater than that on the non-dominant side. The pressure in the first metatarsal region of the dominant side is higher, while that in the midfoot and heel regions is higher on the non-dominant side. badminton players have better forward foot force and heel cushioning ability. Long term badminton sports result in specialized changes in plantar pressure distribution and reduced symmetry.

Discipline-specific adaptation patterns in respiratory and lower limb musculotendinous structures: cyclists vs. basketball players.

This study aimed at assessing how chronic exposure to specific exercise training (high-intensity intervals vs. endurance), comparing experienced basketball-players (BP, N.=16), cyclists (CY, N.=16), and non-specifically trained individuals (CN, N.=16), influences the structural and functional characteristics of both lower limb and respiratory musculotendinous structures. Vastus lateralis, gastrocnemius lateralis, and medialis, diaphragm muscles, as well as patellar tendon and Achilles tendon, were assessed using B-mode ultrasonography. Maximal voluntary isometric and passive torque measurements were conducted in the knee-extensors and plantar-flexors. Additionally, a subset of participants (N.=10 for each group) underwent a fatigue-inducing exercise-till-exhaustion protocol, and the strength of lower limb and respiratory muscles was evaluated immediately before and after the trial. Athletes had bigger and stronger musculotendinous structures and greater endurance to fatigue than CN (P<0.05). BP had bigger plantar-flexors and diaphragm, greater fascicles length, more explosive plantar-flexors and respiratory muscles and bigger tendons than CY (P<0.05). On the other hand, CY showed greater muscle pennation angle and greater endurance to fatigue for both, lower limb, and respiratory muscles (P<0.05). The present study emphasizes that chronic and specific exercise training leads to distinctive adaptations, not only in lower limb musculotendinous structures but also in other components such as respiratory muscles.

Light Physical Activity Throughout the Day and Physical Function in Older Adults

Abstract Background Light physical activity (LPA) plays a crucial role in preventing muscle loss and disability in older adults. Since LPA makes up a significant portion of daily activity, understanding how the timing of LPA influences physical function is important for designing effective health interventions. Methods This cross-sectional study investigated the association between the timing of LPA and physical function among 200 older adults (mean age 76.3, 55.5% female) attending the geriatric outpatient clinic at National Taiwan University Hospital. LPA was objectively measured using wrist-worn accelerometers for seven consecutive days. Principal component analysis (PCA) was used to identify distinct patterns of LPA timing. Participants underwent assessments of grip strength, basic mobility, walking speed, and lower limb muscle strength. Multivariable linear regression models were adjusted for potential confounders, including gender, age, moderate-to-vigorous physical activity (MVPA), and accelerometer wear time. Results Our findings revealed that higher levels of LPA during the morning to noon period were positively associated with better performance across all four physical function tests. Moreover, after controlling for relevant confounders, increased LPA in the late afternoon and evening was positively associated with enhanced basic mobility, walking speed, and lower limb muscle strength. Conclusions This study highlights the importance of considering LPA timing when promoting physical function in older adults, independent of MVPA participation. Encouraging LPA, particularly during the morning to noon period, could be a valuable strategy for maintaining and improving physical capabilities in this population. These findings provide actionable insights for clinicians and health professionals when tailoring physical activity recommendations for older adults within geriatric care settings. Key messages • Morning LPA boosts physical function in seniors, enhancing grip, mobility, walking speed, and muscle strength. • Timing of light activity crucial for older adults’ physical health, with morning to noon activity showing most benefits.

Clinical characteristics of idiopathic inflammatory myopathies related to anti-SRP: a single center experience

Idiopathic inflammatory myopathy (IIM) with autoantibodies recognizing the signal recognition particle (SRP) is characterized by prominent proximal weakness, infrequent extramuscular involvement, dramatically elevated creatine kinase levels, and myofiber necrosis with few inflammatory cell infiltrates in muscle tissue. To enhance understanding of the clinically used diagnosis and treatment of this disease, this study presents a single-center experience and analysis of a Chinese cohort with anti-SRP IIM. The most recent European Neuromuscular Center criteria were used to include Anti-SRP IIM patients from September 2016 to November 2019. Prior to treatment initiation, all sera were collected for the detection of anti-SRP autoantibodies and other myositis-related autoantibodies. Muscle strength, concurrent autoimmune conditions, comorbidities like interstitial lung disease (ILD), treatment outcomes, and follow-up results were also documented. Univariate logistic regression was employed to determine factors affecting prognosis. Among 271 patients with IIM, we identified 23 (8.5%) patients with anti-SRP IIM. Lower limb muscle weakness was frequently more severe. Interstitial lung disease (ILD) was observed in 50% of anti-SRP IIM patients. The presence of ILD may serve as a predictor of a poor prognosis, as revealed by univariate logistic regression analysis (odds ratio, 3.8, 95% CI: 1.0-6.8, p = 0.05).This Chinese Anti-SRP IIM cohort from Hunan province seems to have higher incidences of ILD, and associated ILD may be a risk factor for a poor prognosis. To fully understand the specific role of the anti-SRP autoantibody in this unique subset with ILD, further research is necessary.

The Effect of Blood Flow Restriction Exercise Prior to Total Knee Arthroplasty on Postoperative Physical Function, Lower Limb Strength and Patient-Reported Outcomes: ARandomized Controlled Trial.

30-s sit to stand (30STS). Timed Up&Go, 40-m walk test (40mWT), knee range of motion (ROM) 1-repetition maximum (1RM) leg press and knee extensor strength, maximal isometric contraction (MVIC) for the knee extensors and flexors, Knee injury and Osteoarthritis Outcome Score (KOOS), and Euroqol 5-dimensions (EQ-5D-L5) questionnaire. Data were collected at baseline (12 weeks pre-surgery), ~3 days pre-surgery, 3 and 12 months postoperatively. Intention-to-treat analysis revealed no significant between-group differences in the change from baseline to 3 and 12 months postoperatively on 30STS, TUG, or 40mFWT. Significant between-group differences were observed at 3 but not 12 months postoperatively for the corresponding changes in 1RM leg press strength, 1RM knee extensor strength, and MVIC knee extensor favoring BFR-RT. No between-group differences were observed for the delta changes from baseline in knee ROM, KOOS subscales or EQ-5D-L5 at any postoperative time points. These findings suggest that preoperative BFR-RT offered no superior effects compared with usual preoperative care on postoperative physical function or patient-reported outcomes. Preoperative BFR-RT produced amplified gains in lower limb muscle strength at 3 months postoperatively. NCT04081493.

Effect of foot type on electromyography characteristics and synergy of lower limb muscles during running

The foot structure is associated with different running mechanics. The central nervous system is responsible for using the muscles through synergies during locomotion. The purpose of the present study was to examine the effect of foot structure on the electromyography factors and the synergy of the selected muscles of the lower extremity. Tibialis anterior, extensor digitorum longus, peroneus longus, soleus, biceps femoris, vastus lateralis, gastrocnemius lateralis and medialis muscles activity of 60 barefoot recreational runners with different foot structures was recorded while running at a speed of 3.3 m/s. Muscle activity was measured in the running cycle. Besides, muscle synergies were extracted using non-negative matrix factorization algorithm. The results showed that there were differences between groups with different foot type in muscle activity under different phases of running in some muscles. Furthermore, the findings indicated that the number of synergies was similar in different groups and the relative weight of muscles was not different across groups. In conclusion, despite the difference in muscle activity under different phases of the running cycle, muscle synergies are similar among the groups. This can indicate similar control by the central nervous system in runners with different arch structures while running and the observed changes in muscle activity can be attributed to the type of forces exerted on the body, the length-tension relationship, and changes in the direction of the lower limbs in people with different arch structures.

Changes in Motor Strategy and Neuromuscular Control During Balance Tasks in People with a Bimalleolar Ankle Fracture: A Preliminary and Exploratory Study

Ankle fractures can lead to issues such as limited dorsiflexion, strength deficits, swelling, stiffness, balance disorders, and functional limitations, which complicate daily activities. This study aimed to describe neuromuscular adaptations at 6 and 12 months post-surgery during static and dynamic balance tasks, specifically using the Y-Balance Test (YBT). Additionally, the relationship between neuromuscular patterns, balance, and musculoskeletal deficits was evaluated. In 21 participants (14 at 6 months and 21 at 12 months) with bimalleolar fractures, hip strength, ankle dorsiflexion, ankle functionality, and static and dynamic balance were assessed using electromyography of five lower limb muscles (tibialis anterior, peroneus longus, lateral gastrocnemius, biceps femoris, and gluteus medius). A significant interaction effect (limb × proximal [hip]—distal [ankle] muscle) (F = 30.806, p &lt; 0.001) was observed in the anterior direction of the Y-Balance Test (YBTA) at 6 months post-surgery. During the YBTA and YBT posteromedial (YBTPM), it was found that a lower dorsiflexion range of movement was associated specifically at 6 months with greater activation of the lateral gastrocnemius. However, these differences tended to diminish by 12 months. These findings suggest that neuromuscular patterns differ between operated and non-operated limbs during the YBTA at 6 months post-surgery. The Y-Balance Test, particularly its anterior direction, effectively highlighted these neuromuscular changes. This is a preliminary study; further research is needed to explore these findings in depth.

Use of the international classification of functioning, disability and health in a group of older persons with osteoarticular disorders

Objective: to describe the main structural and functional impairments, activity limitations, and social participation restrictions in elderly individuals with myoarticular dysfunctions using the International Classification of Functioning, Disability, and Health (ICF). Methods: a descriptive, cross-sectional, and retrospective study based on the analysis of clinical and functional data of elderly individuals with osteomyoarticular dysfunctions. A questionnaire including components of Functionality and Disability (ICF, 2004), mobility and stability (Timed Up and Go), lower limb muscle strength (Sit-To-Stand Test), and pain (visual analog scale) was used. Results: a total of 11 elderly individuals (70±1.4 years) with at least two comorbidities (100%) were included, with the majority reporting episodes of falls (54.5%). Pain was the primary complaint in "Body functions," reported by all participants. In "Body structures," the lower limbs (45.4%) and upper limbs (18.1%) had the highest prevalence of complaints. In "Activities and Participation," the most frequently mentioned items were performing housework tasks (31.8%), moving around (31.8%), and recreation and leisure (27.3%). Conclusion: among the ICF components, pain sensation was the most common finding in elderly individuals, especially affecting the lower limbs. Regarding activity limitations and social participation restrictions, performing housework tasks, moving around, and recreation/leisure were prevalent.

Centrally mediated responses to NMES are influenced by muscle group and stimulation parameters

Wide-pulse high-frequency neuromuscular electrical stimulation (WPHF NMES) can generate a progressive increase in tetanic force through reflexive recruitment of motor units, called extra force. This phenomenon has previously been observed on different muscle groups, but little is known on potential inter-muscle differences. We compared extra force and sustained electromyographic (EMG) activity induced by NMES between plantar flexors, knee extensors, elbow flexors and within muscle groups using pulse durations of 0.2, 1 and 2 ms and stimulation frequencies of 20, 50, 100 and 147 Hz. Extra force production and sustained EMG activity were higher for plantar flexors compared to elbow flexors at all tested parameters (except 0.2 ms for extra force). When compared to elbow flexors, extra force of the knee extensors was only higher at 100 Hz and with 1 ms while sustained EMG activity was higher at all frequencies with pulse durations of 0.2 and 2 ms. Peripheral nerve architecture as well as muscle typology and function could influence the occurrence and magnitude of centrally-mediated responses to NMES. The present findings suggest that the use of wide-pulse high-frequency NMES to promote reflexive recruitment seems to be more pertinent for lower limb muscles, plantar flexors in particular.