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BACKGROUND: Postural control imposes higher demands on the central neural system (CNS), and age-related declines or incomplete CNS development often result in challenges performing tasks like forward postural leaning. Studies on older adults suggest increased variability in center of pressure (COP), greater muscle co-activations, and reduced corticospinal control during forward leaning tasks. However, the understanding of these features in children remains unclear. Specifically, it is uncertain whether forward leaning poses greater challenges for young children compared to adults, given the ongoing maturation of CNS during development. Understanding the distinct neuromuscular patterns observed during postural leaning could help optimize therapeutic strategies aimed at improving postural control in pediatric populations. METHODS: 12 typically developing children (5.91 ±â€¯1.37 years) and 12 healthy young adults (23.16 ±â€¯1.52 years) participated in a dynamic leaning forward task aimed at matching a COP target in the anterior-posterior direction as steadily as possible. Participants traced a triangular trajectory involving forward leaning (FW phase) to 60 % of their maximum lean distance and backward returning (BW phase) to the neutral standing position. Surface electromyography (sEMG) from muscles including gastrocnemius medialis (GM), soleus (SOL), and tibialis anterior (TA) were collected during both phases. COP variability was assessed using the standard deviation (SD) of COP displacements. Muscle co-activation indexes (CI) for ankle plantar and dorsal flexors (SOL/TA, GM/TA) were derived from sEMG activities. Intermuscular coherence in the beta band (15-30 Hz) was also analyzed to evaluate corticospinal drive. RESULTS: Children exhibited a significantly greater SD of COP compared to young adults (p < 0.01) during the BW phase. They also demonstrated higher CI (p < 0.05) and reduced coherence of SOL/TA (p < 0.05) compared to young adults during this phase. No significant group differences were observed during the FW phase. Within the children's group, COP variability was significantly higher in the BW phase compared to the FW phase (p < 0.01). Moreover, children displayed greater CI (p < 0.01) and reduced coherence of SOL/TA (p < 0.01) during the BW phase compared to the FW phase. Conversely, no significant phase effects were observed in the adult group. Furthermore, sEMG measures were significantly correlated with COP variability (p < 0.05). CONCLUSIONS: The findings of this small study suggest that age-related differences in CNS development influence the modulation of corticospinal drive to ankle muscles (e.g., SOL/TA) during childhood, particularly supporting the existence of a separate pathway underlying the control of forward lean and backward returning.

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Musculoskeletal simulations with muscle optimization aim to minimize muscle effort, hence are considered unable to predict the activation of antagonistic muscles. However, activation of antagonistic muscles might be necessary to satisfy the dynamic equilibrium. This study aims to elucidate under which conditions coactivation can be predicted, to evaluate factors modulating it, and to compare the antagonistic activations predicted by the lumbar spine model with literature data. Simple 2D and 3D models, comprising of 2 or 3 rigid bodies, with simple or multi-joint muscles, were created to study conditions under which muscle coactivity is predicted. An existing musculoskeletal model of the lumbar spine developed in AnyBody was used to investigate the effects of modeling intra-abdominal pressure (IAP), linear/cubic and load/activity-based muscle recruitment criterion on predicted coactivation during forward flexion and lateral bending. The predicted antagonist activations were compared to reported EMG data. Muscle coactivity was predicted with simplified models when multi-joint muscles were present or the model was three-dimensional. During forward flexion and lateral bending, the coactivation ratio predicted by the model showed good agreement with experimental values. Predicted coactivation was negligibly influenced by IAP but substantially reduced with a force-based recruitment criterion. The conditions needed in multi-body models to predict coactivity are: three-dimensionality or multi-joint muscles, unless perfect antagonists. The antagonist activations are required to balance 3D moments but do not reflect other physiological phenomena, which might explain the discrepancies between model predictions and experimental data. Nevertheless, the findings confirm the ability of the multi-body trunk models to predict muscle coactivity and suggest their overall validity.

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BACKGROUND: Children with Cerebral Palsy (CP) walk with an uncoordinated gait compared to Typically Developing (TD) children. This behavior may reflect greater muscle co-activation in the lower limb; however, findings are inconsistent, and the determinants of this construct are unclear. RESEARCH OBJECTIVES: (i) Compare lower-limb muscle co-activation during gait in children with, and without CP, and (ii) determine the extent to which muscle co-activation is influenced by electromyography normalization procedures and Gross Motor Function Classification System (GMFCS) class. METHODS: An electromyography system measured muscle activity in the rectus femoris, semitendinosus, gastrocnemius, and tibialis anterior muscles during walking in 46 children (19 CP, 27 TD). Muscle co-activation was calculated for the tibialis anterior-gastrocnemius (TA-G), rectus femoris-gastrocnemius (RF-G), and rectus femoris-semitendinosus (RF-S) pairings, both using root mean squared (RMS)-averaged and dynamically normalized data, during stance and swing. Mann-Whitney U and independent t-tests examined differences in muscle co-activation by group (CP vs. TD) and GMFCS class (CP only), while mean difference 95% bootstrapped confidence intervals compared electromyography normalization procedures. RESULTS: Using dynamically normalized data, the CP group had greater muscle co-activation for the TA-G and RF-G pairs during stance (p < 0.01). Using RMS-averaged data, the CP group had greater muscle co-activation for TA-G (stance and swing, p < 0.01), RF-G (stance, p < 0.05), and RF-S (swing, p < 0.01) pairings. Muscle co-activation calculated with dynamically normalized, compared to RMS-averaged data, were larger in the RF-S and RF-G (stance) pairs, but smaller during swing (RF-G). Children with CP classified as GMFCS II had greater muscle co-activation during stance in the TA-G pair (p < 0.05). SIGNIFICANCE: Greater muscle co-activation observed in children with CP during stance may reflect a less robust gait strategy. Although data normalization procedures influence muscle co-activation ratios, this behavior was observed independent of normalization technique.

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BACKGROUND: Multiple sclerosis (MS) is a progressive neurodegenerative disease characterized by axonal degeneration and demyelination. Changes in gait, related to joint kinematics and kinetics, especially at the ankle and knee, have been observed in people with MS (pwMS). Muscle coactivation plays an important role in joint stabilization; however, excessive coactivation may interfere with gait. The aim of this study was to analyze the differences in muscle activation during gait in pwMS compared to healthy individuals. METHODS: A cross-sectional study was conducted involving pwMS and healthy controls. Surface electromyography was used to record muscle activity during gait. The main outcome measures were the coactivation index (CI) and the area under the curve (AUC), which were calculated for several pairs of lower extremity muscles. RESULTS: Nine pwMS and nine healthy controls were included. When comparing the MS group to the control group, the AUC was significantly higher in the lateral gastrocnemius (p = 0.023) and the CI for the lateral gastrocnemius-anterior tibialis (p = 0.022) and gluteus maximus-lateral gastrocnemius (p = 0.047). CONCLUSION: Mildly affected pwMS have altered muscle coactivation patterns during gait, especially in the most affected limb. The results highlight the importance of muscle coactivation in pwMS and its possible role in the early detection of gait abnormalities.

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This systematic review is aimed to provide an up-to-date summary and review on the use of surface electromyography (sEMG) in evaluating front crawl (FC) swim performance. Several online databases were searched by different combinations of selected keywords, in total 1956 articles were retrieved, and each article was assessed by a 10-item quality checklist. 16 articles were eligible to be included in this study, and most of the articles were evaluating the muscle activity about the swimming phases and focused on assessing the upper limbs muscles, only few studies have assessed the performance in starts and turns phases. Insufficient information about these two phases despite the critical contribution on final swimming time. Also, with the contribution roles of legs and trunk muscles in swimming performance, more research should be conducted to explore the overall muscle activation pattern and their roles on swimming performance. Moreover, more detailed description in participants' characteristics and more investigations of bilateral muscle activity and the asymmetrical effects on relevant biomechanical performance are recommended. Lastly, with increasing attention about the effects of muscles co-activation on swimming performance, more in-depth investigations on this topic are also highly recommended, for evaluating its influence on swimmers.

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BACKGROUND: Compared to typically developing children, children with cerebral palsy (CP) have increased energy expenditure during walking, limiting activity and participation. Insight into whether the also deviating and more asymmetric gait with increased muscle co-activation contributes to this increased energy expenditure is important for clinical decision making. The aim of this study was to investigate the relation between energy cost of walking with gait deviation, asymmetry, and muscle co-activation in children with CP. METHODS: Forty ambulant children with CP, with Gross Motor Function Classification System (GMFCS) level I (N = 35) and II (N = 5), aged between 5-17y, were tested at one or two occasions with 24 weeks in between, resulting in 71 observations. Gross energy cost (J/kg/m) was measured during a 5-min walk test at self-selected speed. From a 3-dimensional gait analyses, kinematic variables and electromyography were extracted to calculate the gait deviation index (GDI) and co-activation index. The relation between energy cost and GDI, GDI asymmetry, and co-activation index of the lower limb muscles was evaluated through mixed model analyses. Height was included to control for growth-related variation. RESULTS: Gait deviation and height combined explained about 40% of the variance in gross energy cost. No significant contribution was found for gait asymmetry or co-activation index. CONCLUSIONS: This cross-sectional study indicates that increased gait deviation contributes to increased energy cost of walking in children with GMFCS level I and II.

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BACKGROUND: The purpose of this study was to investigate the differences in the muscle activity and co-activation index (CoA) of the rectus femoris (RF), biceps femoris (BF), gastrocnemius medialis (GM,) and tibialis anterior (TA) during walking on land and in water in healthy adolescents compared with those with spastic diplegia cerebral palsy (CP) adolescents. METHODS: Four healthy individuals (median; age: 14 years, height: 1.57 cm, BMI: 16.58 kg/m2) and nine CP individuals (median; age: 15 years, height: 1.42 cm, BMI: 17.82 kg/m2) participated in this study and performed three walking trials under both conditions. An electromyography (EMG) collection was recorded with a wireless system Cometa miniwave infinity waterproof device, and the signals were collected using customized software named EMG and Motion Tools, Inc. software version 7 (Cometa slr, Milan, Italy) and was synchronized with an underwater VDO camera. RESULTS: A significant decrease in the muscle activity of all muscles and CoA of RF/BF muscles, but an increase in TA/GM was observed within the CP group while walking in water during the stance phase. Between groups, there was a lower CoA of RF/BF and a greater CoA of TA/GM during the stance phase while walking in water and on land in the CP group. A non-significant difference was observed within the healthy group. CONCLUSION: Walking in water can decrease muscle activity in lower limbs and co-activation of thigh muscles in people with spastic CP, whereas CoA muscles around ankle joints increased to stabilize foot weight acceptance.

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When moving a piano or dancing tango with a partner, how should I control my arm muscles to sense their movements and follow or guide them smoothly? Here we observe how physically connected pairs tracking a moving target with the arm modify muscle coactivation with their visual acuity and the partner's performance. They coactivate muscles to stiffen the arm when the partner's performance is worse and relax with blurry visual feedback. Computational modeling shows that this adaptive sensing property cannot be explained by the minimization of movement error hypothesis that has previously explained adaptation in dynamic environments. Instead, individuals skillfully control the stiffness to guide the arm toward the planned motion while minimizing effort and extracting useful information from the partner's movement. The central nervous system regulates muscle activation to guide motion with accurate task information from vision and haptics while minimizing the metabolic cost. As a consequence, the partner with the most accurate target information leads the movement.NEW & NOTEWORTHY Our results reveal that interacting humans inconspicuously modulate muscle activation to extract accurate information about the common target while considering their own and the partner's sensorimotor noise. A novel computational model was developed to decipher the underlying mechanism: muscle coactivation is adapted to combine haptic information from the interaction with the partner and own visual information in a stochastically optimal manner. This improves the prediction of the target position with minimal metabolic cost in each partner, resulting in the lead of the partner with the most accurate visual information.

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The aim of this study was to determine muscle co-activation and muscle activity time using EMG in Paralympic wheelchair fencers categorized into two disability-level groups: A (n= 7) and B (n= 9). The study was carried out with the use of a 16-channel EMG system. The surface EMG electrodes were placed on the fencer's body along nine channels: arm muscles - deltoideus middle head (DEL), triceps brachii (TRI) and biceps brachii (BC); forearm muscles - extensor carpi radialis longus (ECR), flexor carpi radialis (FCR); postural (abdominal and back) muscles - the right and the left external oblique abdominal (EOA RT and LT) and latissimus dorsi (LD RT and LT). To assess the relative level of co-activation (simultaneous contraction of both muscles) for the TRI-BC, ECR-FCR, LD RT-EDA RT and LD LT-EDA LT muscle pairs, the co-activation index (CI) was calculated. The collected data were processed using Jamovi. The study hypotheses were verified at the level of significance of p≤0.05 (Welch's t-test). The normal distribution of analyzed statistical features was checked with the Shapiro-Wilk test. The analysis of muscle activation time, as a percent ratio of three attempts executed in a series, confirmed the study assumptions. Fencers from Group A had a shorter activation time in all tested muscles, with the exception of the ECR (58.24), than fencers from Group B. This confirms that the activation of antagonist muscles representing a centrally programmed anticipatory mechanism stabilizing technical actions was particularly intensified in Group A fencers. The study results indicate that the standard co-activation index (CI) of key muscles involved in wheelchair fencing ranges from 48 to 51%.

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OBJECTIVE: To assess the correlation between fetal head regression and levator ani muscle (LAM) co-activation under Valsalva maneuver. STUDY DESIGN: This study was a secondary analysis of a prospective cohort study on the association between the angle of progression (AoP) and labor outcome. We scanned a group of nulliparous women at term before the onset of labor at rest and under maximum Valsalva maneuver. In addition to the previously calculated AoP, in the present study, we measured the anteroposterior diameter of LAM hiatus (APD) on each ultrasound image. LAM co-activation was defined as APD at Valsalva less than that at rest, whereas fetal head regression was defined as AoP at Valsalva less than that at rest. We calculated the correlation between the two phenomena. Finally, we examined various labor outcomes according to the presence, absence, or co-existence of these two phenomena. RESULTS: We included 469 women. A total of 129 (27.5%) women presented LAM co-activation while 50 (10.7%) showed head regression. Only 15 (3.2%) women showed simultaneous head regression and LAM co-activation. Women with coexisting LAM co-activation and head regression had the narrowest AoP at Valsalva in comparison with other study groups (p < .001). In addition, they had the highest risk of Cesarean delivery (40%) and longest first, second, and active second stage durations, although none of these reached statistical significance. CONCLUSION: In nulliparous women at term before the onset of labor fetal head regression and LAM co-activation at Valsalva are two distinct phenomena that uncommonly coexist.

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Fear of falling increases conscious control of balance and postural threat warrants accurate anticipatory motor commands for keeping a safe body posture. This study examines the anticipatory (APAs) and compensatory (CPAs) postural adjustments generated in response to an external perturbation while individuals are positioned at two different altitudes (2 cm and 80 cm) from the floor level. The main result indicates that due to the perceived emotional threat, different agonist and antagonist muscles synergies (R and C-Indexes) are manifested, particularly during the anticipatory phase. The results suggest that the CNS sends central commands for anticipating postural adjustments by adopting primarily a muscle reciprocal activation instead of a muscle co-activation strategy. Interestingly, the APAs strategies were modified under different postural threats by controlling the agonist-antagonist muscles at different joints of lower extremity. For CPAs the reciprocal activation was less applied compared to muscles co-activation to unsure larger margin for compensatory adjustments as needed and re-establish the postural stability. The results indicate that when facing to a postural threat, the CNS modulates the anticipatory and compensatory phases of postural adjustments to minimize the risk of falling.

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Lifting tasks are manual material-handling activities and are commonly associated with work-related low back disorders. Instrument-based assessment tools are used to quantitatively assess the biomechanical risk associated with lifting activities. This study aims at highlighting different motor strategies in people with and without low back pain (LBP) during fatiguing frequency-dependent lifting tasks by using parameters of muscle coactivation. A total of 15 healthy controls (HC) and eight people with LBP performed three lifting tasks with a progressively increasing lifting index (LI), each lasting 15 min. Bilaterally erector spinae longissimus (ESL) activity and rectus abdominis superior (RAS) were recorded using bipolar surface electromyography systems (sEMG), and the time-varying multi-muscle coactivation function (TMCf) was computed. The TMCf can significantly discriminate each pair of LI and it is higher in LBP than HC. Collectively, our findings suggest that it is possible to identify different motor strategies between people with and without LBP. The main finding shows that LBP, to counteract pain, coactivates the trunk muscles more than HC, thereby adopting a strategy that is stiffer and more fatiguing.

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OBJECTIVE: To assess the association between sonographic findings at transperineal ultrasound (TPU) and chronic constipation (CC) in women with endometriosis. METHODS: An observational prospective cohort study was performed by enrolling all women with endometriosis scheduled for surgery between September 2019 and October 2020. Women underwent TPU at rest and during Valsalva maneuver evaluating levator-hiatal-area (LHA), antero-posterior diameter (APD), and levator ani muscle (LAM) coactivation. Ultrasound findings were compared between women with and without CC in the whole study population, and subsequently in two subgroups (only ovarian endometriosis and deep infiltrating endometriosis [DIE]). RESULTS: In all, 87 women were enrolled: 29 (33%) with CC and 58 (67%) without CC. Women with endometriosis and CC showed a smaller LHA during Valsalva, less LHA and APD enlargement from rest to maximum Valsalva, and a higher prevalence of LAM coactivation compared with women without CC. In the ovarian subgroup, women with CC had smaller LHA at Valsalva, less enlargement of LHA and APD from rest to maximum Valsalva, and higher prevalence of LAM coactivation compared with non-CC patients. In the DIE subgroup, TPU did not significantly differ between CC and non-CC patients. CONCLUSION: TPU signs of pelvic floor muscle hypertonia are more frequent in endometriosis patients with CC compared with those without constipation, particularly in women affected by isolated ovarian endometriosis.

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Falls in the aging population are a major public health concern. Outdoor falls in community-dwelling older adults are often triggered by uneven pedestrian walkways. Our understanding of the motor control adaptations to walk over an uneven surface, and the effects of aging on these adaptations is sparse. Here, we study changes in muscle co-contraction, a clinically accepted measure of motor control, due to changes in walking surfaces typically encountered in the outdoor built environment. We address the following research questions: 1) are there walking surface and sex-based differences in muscle co-contractions between young and older adults? and 2) is muscle co-contraction associated with age? We calculated muscle co-contractions from 13 young and 17 older adults during walking at self-selected speeds over even and uneven brick walkways. Muscle co-contraction at the ankle joint was determined from the tibialis anterior and lateral gastrocnemius muscle pair, and at the knee joint from the rectus femoris and semitendinosus muscle pair. Older adults displayed 8-13% greater ankle muscle co-contractions during walking over uneven compared to even surfaces. We found 55-61% (entire gait) and 73-75% (stance phase) greater ankle muscle co-contractions in older females compared to older males during walking over even and uneven surfaces. We found 31-43% greater knee muscle co-contractions in older females compared to older males during the swing phase of walking over even and uneven surfaces. This study underscores the need for determining muscle co-contractions from even and uneven surfaces for quantifying motor control deficits due to aging or neuromuscular disorders.

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BACKGROUND: There is insufficient information on muscle co-activation in the upper limbs to help healthcare providers develop treatment programs for patients with dyskinetic cerebral palsy (DCP). RESEARCH QUESTION: Is the degree of muscle co-activation greater in adults with DCP than in healthy individuals? Does the use of different arm weights modify co-contraction in individuals with PCD? METHODS: Fourteen healthy individuals (control group [CG]) and 14 individuals with DCP (dyskinetic group [DG]) participated in the study. The degree of muscle co-activation of the dominant limb during drinking from a mug was compared between the two groups. The task was divided into a going, adjusting, and returning phase. In the DG, an analysis was also performed on using an arm weight during the functional task. The loads corresponded to 10, 20, and 30 % of maximum isometric muscle strength measured in each participant. RESULTS: In comparing the two groups, the DG exhibited a greater muscle co-activation in the shoulder and elbow muscles during the going phase, the shoulder, elbow, and wrist during the adjusting phase; and the elbow during the returning phase. The DG also showed a greater mean index of curvature (MIC), time to perform the movement phases, and lesser mean velocity (Vm) to drinking. In analyzing the DG's arm weight, no effect on co-activation, MIC, time to perform the movement phases, and Vm to drinking were found with the loads tested (p > 0.05). CONCLUSION: Muscle co-activation is increased in adults with DCP in comparison to healthy individuals. Moreover, arm weight during the functional activity of drinking from a mug did not alter co-activation, although an immediate effect was expected.

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Tasks of daily life require the independent use of the arms and hands. Individuals with hemiparetic cerebral palsy (HCP) often experience difficulty with fine motor tasks demonstrating mirrored movements between the arms. In this study, bilateral muscle activations were quantified during single arm isometric maximum efforts and submaximal reaching tasks. The magnitude and direction of mirrored activation was examined in 14 individuals with HCP and 9 age-matched controls. Participants generated maximum voluntary torques (MVTs) in five different directions and completed ballistic reaches while producing up to 80% of shoulder abduction MVT. Electromyography (EMG) signals were recorded from six upper extremity muscles bilaterally. Participants with HCP demonstrated more mirrored activation when volitionally contracting the non-paretic (NP) arm than the paretic arm (F = 83.543, p < 0.001) in isometric efforts. Increased EMG activation during reach acceleration resulted in a larger increase in rest arm co-activation when reaching with the NP arm compared to the paretic arm in the HCP group (t = 8.425, p < 0.001). Mirrored activation is more pronounced when driving the NP arm and scales with effort level. This directionality of mirroring is indicative of the use of ipsilaterally terminating projections of the corticospinal tract (CST) originating in the non-lesioned hemisphere. Peripheral measures of muscle activation provide insight into the descending pathways available for control of the upper extremity after early unilateral brain injury.

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BACKGROUND: In patients with peripheral arterial disease and presenting intermittent claudication (PAD-IC), the pain due to ischemia impacts gait parameters, particularly in cases of unilateral disease. Deterioration of gait parameters in a pathological context is frequently associated with increased coactivation (simultaneous activation of agonist and antagonist muscles around a joint). RESEARCH QUESTION: Does unilateral PAD-IC affect the coactivation pattern during walking? Does the coactivation pattern change with increasing pain intensity? METHOD: We evaluated symptomatic and asymptomatic legs in 17 subjects with unilateral PAD-IC and 16 without PAD-IC (control group), during walking. Tibialis anterior (TA) and gastrocnemius medialis (GM) electromyographic activity, and peaks of vertical ground reaction force were recorded in this prospective study. We analyzed the coactivation index (CI(GM/TA)) during three periods (pain-free, pain and maximum pain) and phases of the gait cycle. Statistical analysis was carried out using the ANOVA procedure. RESULTS: During single support, CI(GM/TA) increases in the symptomatic leg during the pain period (+28 %) and in the asymptomatic leg during the maximum pain period (+29 %). During second double support, CI(GM/TA) increases in the symptomatic leg only (+49 %). In these gait phases, pain elicits differences in CI(GM/TA) between legs (p < 0.05). Second peak force decreases in the symptomatic leg only (-9%) and is negatively correlated with CI(GM/TA) during the three periods (r = -0.57; -0.76 and -0.78 respectively, p < 0.05). No difference is found in the control group. SIGNIFICANCE: The appearance and development of pain in the lower limbs is associated with a higher level of CI(GM/TA), revealing a compensatory gait pattern in PAD-IC patients. Optimal prevention, rehabilitation and re-training strategies for PAD-IC patients should take into consideration neuromuscular compensatory mechanisms between asymptomatic and symptomatic legs.

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In Duchenne muscular dystrophy (DMD), one of the most severe and frequent genetic diseases in humans, dystrophic muscles are prone to damage caused by mechanical stresses during eccentric contractions. Eccentric contraction during walking on level ground likely contributes to the progression of degeneration in lower limb muscles. However, little is known about how the amount of muscle eccentric contractions is affected by uphill/downhill sloped walking, which is often encountered in patients' daily lives and poses different biomechanical demands than level walking. By recreating the dynamic musculoskeletal simulations of downhill (-9°, -6°, and -3°), uphill (+3°, +6°, and +9°) and level walking (0°) from a published study of healthy participants, negative muscle mechanical work, as a measure of eccentric contraction, of 35 lower limb muscles was quantified and compared. Our results indicated that downhill walking overall induced more (32% at -9°, 19% at -6°, and 13% at -3°) eccentric contractions in lower limb muscles compared to level walking. In contrast, uphill walking led to eccentric contractions similar to level walking at low grades (+3° and +6°), but 17% more eccentric contraction at high grades (+9°). The changes of muscle eccentric contraction were largely predicted by the changes in both joint negative work and muscle coactivation in sloped walking. As muscle eccentric contractions play a critical role in the disease progression in DMD, this study provides an important baseline for future studies to safely improve rehabilitation strategies and exercise management for patients with DMD and other similar conditions.

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BACKGROUND: The integration of therapeutic approaches is increasingly recommended for children with cerebral palsy, to enhance outcomes. Nevertheless, clinicians still opt for separate or combined therapies based on little credible knowledge. OBJECTIVE: This study endeavored to evaluate the effect of botulinum neurotoxin-A (BoNT-A) injection and reciprocal neuromuscular electrical stimulation (rNMES) and their combination on the upper extremity function in children with spastic hemiplegia. METHODS: Sixty-four children with spastic hemiplegia (aged 6- 10 years) were randomly assigned to four treatment-based groups [group I (BoNT-A), group II (rNMES), group III (combined BoNT-A and rNMES), and group IV (Control)]. All children received a physical rehabilitation program, thrice/week over three months. Unilateral upper-limb function, bimanual hand function, and real-time arm-hand function were assessed using Melbourne Assessment (MA), Assisting Hand Assessment (AHA), and Pediatric Motor Activity Log (PMAL) scales respectively pre-treatment, post-treatment, and at 6 months follow-up. RESULTS: Post-treatment, group III achieved greater improvement in MA, AHA, and PMAL compared to other groups (all P < 0.05), and the difference remained in favor of group III at the follow-up (all P < 0.05). CONCLUSIONS: This study suggests that BoNT-A and rNMES combined are more effective than either of them alone to enhance upper-extremity function in children with spastic hemiplegia.

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Spinal cord injury (SCI) produces muscle wasting that is especially severe after complete and permanent damage of lower motor neurons, as can occur in complete conus and cauda equina syndrome. Even in this worst-case scenario, mass and function of permanently denervated quadriceps muscle can be rescued by surface functional electrical stimulation using a purpose designed home-based rehabilitation strategy. Early diagnostics is a key factor in the long-term success of this management. Function of quadriceps muscle was quantitated by force measurements. Muscle gross cross-sections were evaluated by quantitative color computed tomography (CT) and muscle and skin biopsies by quantitative histology, electron microscopy, and immunohistochemistry. Two years of treatment that started earlier than 5 years from SCI produced: (a) an increase in cross-sectional area of stimulated muscles; (b) an increase in muscle fiber mean diameter; (c) improvements in ultrastructural organization; and (d) increased force output during electrical stimulation. Improvements are extended to hamstring muscles and skin. Indeed, the cushioning effect provided by recovered tissues is a major clinical benefit. It is our hope that new trials start soon, providing patients the benefits they need.