Search Results (33)

Background: Current clinical practice still lacks consistent evidence in the physiotherapy management of rotator cuff-related pain syndrome (RCS). The purpose of this trial was to compare the effectiveness of a scapular-focused treatment with and without real-time electromyographic biofeedback (EMGBF) to a control therapy in patients with RCS, in the short-term. Methods: 60 patients with RCS were divided into three groups: the scapular-focused exercise protocol group (P_G n = 20), the scapular-focused exercise protocol with EMGBF group (P+EMGBF_G n = 20), and the control therapy group (CT_G n = 20). Values of pain and function [Shoulder Pain and Disability Index (SPADI) questionnaire, complemented by the Numeric Pain Rating Scale (NPRS) and Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire], scapular stabilizer neuromuscular control (SSNC), scapular stabilizer activation onset (SSAO), dynamic scapular alignment, range of motion (ROM), and glenohumeral flexor and abductor muscle strength (GMS) were assessed at baseline and after 6 weeks and compared within and between groups. Results: There were significant differences in pain and function, SSNC, SSAO, dynamic scapular alignment, ROM, and GMS in all groups between the initial and 6-week assessments. However, the P+EMGBF_G showed superior results in pain and function, SSNC, and dynamic scapular alignment than the CT_G and superior results in SSNC than the P_G. The P_G had superior results in pain and function and dynamic scapular alignment than the CT_G. Conclusions: This trial supports the use of a scapular-focused exercise protocol as a comparative approach that effectively improves pain and function in patients with rotator cuff-related shoulder pain syndrome. These results in pain and function were shown to be independent of the use of EMGBF. Full article

Background/Objectives: Three-dimensional (3D) spinal and pelvic alignment plays a critical role in maintaining anticipatory postural control. However, the extent to which specific multiplanar alignment parameters influence feedforward activation of trunk stabilizing muscles remains unclear. This study aimed to determine whether sagittal, coronal, and transverse postural deviations predict anticipatory muscle activation patterns during externally induced perturbations. Methods: Surface electromyography (EMG) was recorded from bilateral external oblique (EO), lumbar multifidus (LM), and transversus abdominis/internal oblique (TrA/IO) muscles in 100 asymptomatic young adults (18–25 years) performing dynamic right-leg raises. Spinal and pelvic alignment was quantified using rasterstereography, including sagittal and coronal imbalance, pelvic tilt, torsion, rotation, vertebral rotation, and spinal curvatures (kyphotic and lordotic angles). Regression models examined how these parameters predicted EMG onset latency and activation amplitude. Results: Distinct alignment patterns were associated with altered anticipatory control. Increased vertebral rotation and greater sagittal imbalance were linked to delayed activation of EO and LM, while asymmetries in pelvic torsion and tilt were related to less efficient TrA/IO recruitment. Conversely, more balanced spinal curvatures corresponded with earlier, more coordinated muscle activation across the trunk. Conclusions: Multiplanar spinal and pelvic alignment significantly influences anticipatory neuromuscular strategies. Identifying how specific postural deviations disrupt feedforward activation provides a functional basis for targeted rehabilitation programs aiming to restore alignment, enhance trunk stability, and prevent recurrent postural dysfunction. Full article

The present study aimed to investigate the effects of a 12-week Core Stability Training (CST) program on trunk mobility (twisting and bending), upper quarter dynamic balance (UQ-YBT scores), and postural asymmetry indices (Anterior—ATSI—and Posterior Trunk Symmetry Indices—POTSI) of university students. This study examined the effects of a 12-week CST program on trunk mobility and dynamic balance in 181 university students (70 females, 111 males; aged 18–24 years). Participants completed one supervised 90–100-min session per week. Baseline postural symmetry, assessed with the ATSI and POTSI, showed no sex differences. After training, trunk mobility improved significantly (p < 0.001). The female group increased twisting by 5.3° and bending by 6.5 cm, while the male group improved by 4.7–6.1° and 6.0–6.1 cm, respectively (η² = 0.625–0.773). Dynamic balance measured by the UQ-YBT also improved in all directions (p < 0.001). Mean gains ranged from 4.0 to 9.7 points, with large effect sizes, especially in males (η² up to 0.842). CST effectively enhanced trunk mobility and upper trunk stability in both sexes. Although postural asymmetry did not change, the program improved neuromuscular control and balance, demonstrating its value in promoting postural health among university students. Full article

Background/Objective: Postural stability and motor coordination require precise regulation of agonist and antagonist muscle activities. Jaw clenching modulates neuromuscular control during static and reactive postural tasks. However, its effects on dynamic voluntary movement remain unclear. This pilot study aimed to investigate the effects of jaw clenching on muscle activity and kinematics during repetitive single-leg sit-to-stand task performance. Methods: Eleven healthy adults (age: 21.2 ± 0.4 years; 6 males and 5 females; height: 167.9 ± 9.6 cm; body weight: 59.7 ± 8.1 kg) performed repetitive single-leg sit-to-stand tasks for 30 s under jaw-clenching and control conditions. Electromyography (EMG) signals from eight muscles and kinematic data from 16 inertial measurement unit sensors were analyzed, focusing on the seat-off phase. Results: Jaw clenching resulted in a significantly lower success rate than the control condition (success rate: 0.96 ± 0.13 vs. 0.78 ± 0.29, p = 0.047). Under the jaw clenching condition, failed trials exhibited higher medial gastrocnemius and masseter EMG activity (p < 0.001), lower erector spinae longus EMG activity (p < 0.001), and altered kinematics, including increased trunk yaw and roll angles (p < 0.001). Jaw clenching increased the coactivation of the gastrocnemius and tibialis anterior muscles (p < 0.001), disrupting the reciprocal muscle patterns critical for task performance. Conclusions: These findings suggest that jaw clenching may reduce task performance by altering neuromuscular coordination during dynamic postural tasks. Full article

Background and Objectives: Chronic low back pain (CLBP) is associated with altered neuromuscular control. Dynamic Neuromuscular Stabilization (DNS) targets core–limb coordination; however, its specific impact on lower-limb electromyographic (EMG) activity during gait remains unclear. Materials and Methods: Fifty-five young adults with non-specific CLBP (pain ≥ 3 months with no identifiable specific pathology) completed the trial (overall mean age 23.7 ± 1.3 years). Participants were randomized to an 8-week DNS program or a control. Pre-/Post-intervention surface EMG during gait and clinical outcomes (VAS, ODI) were assessed. Results: Compared with control, DNS showed lower adjusted Post-test VAS (3.08 ± 0.25 vs. 6.13 ± 0.24; ηp² = 0.596) and ODI (15.73 ± 1.55% vs. 34.36 ± 1.52%; ηp² = 0.579). Directionally, DNS was associated with phase-specific EMG modulation: tibialis anterior during mid-stance was lower (ηp² = 0.137), rectus femoris during push-off was lower (ηp² = 0.119), biceps femoris during push-off was lower (ηp² = 0.168), and vastus medialis at heel-strike was higher (ηp² = 0.077) relative to control. Other muscle–phase pairs showed no adjusted between-group differences. Conclusions: An 8-week DNS program was associated with clinically meaningful reductions in pain and disability and with phase-specific changes in lower-limb EMG during gait. These findings support DNS as a promising rehabilitation option for young adults with CLBP; confirmation in larger trials with active comparators is warranted. Full article

Stroke often leads to persistent upper limb dysfunction that impairs activities of daily living, yet objective biomechanical indicators for precise assessment remain limited. This study aimed to characterize phase-specific impairments in energy output, torque stability, and muscle coordination during the hand-to-mouth (HTM) task and to explore their potential for improving rehabilitation evaluation. Motion data from 20 stroke patients and 20 healthy controls were recorded using wearable surface electromyography and inertial measurement unit systems. A musculoskeletal model was applied to calculate joint torque, mechanical work, torque smoothness, and a novel torque-based co-contraction index across four movement subphases. These phase-specific metrics demonstrated significant correlations with clinical motor impairment scores, confirming their clinical validity. Significant dynamic features were then selected to construct machine learning models for group classification. Stroke patients showed reduced output capacity, increased torque fluctuations, and abnormal co-contraction patterns that varied across subphases. Among the classifiers, the quadratic support vector machine achieved the best performance, with an accuracy of 84.6% and an AUC of 0.853, surpassing models based on whole-task features. These findings demonstrate that phase-specific biomechanical features sensitively capture neuromuscular deficits in stroke survivors and highlight the potential of phase-specific biomechanics to inform future individualized rehabilitation assessment and treatment planning. Full article

(1) Background: Chronic ankle instability (CAI), a common outcome of ankle sprains, involves recurrent sprains, balance deficits, and gait impairments linked to both peripheral and central neuromuscular dysfunction. Dual-task (DT) demands further aggravate postural control, especially during stair descent, a major source of fall-related injuries. Yet the biomechanical mechanisms of stair-to-ground transition in CAI under dual-task conditions remain poorly understood. (2) Methods: Sixty individuals with CAI and age- and sex-matched controls performed stair-to-ground transitions under single- and dual-task conditions. Spatiotemporal gait parameters, center of pressure (COP) metrics, ankle inversion angle, and relative joint work contributions (Ankle%, Knee%, Hip%) were obtained using 3D motion capture, a force plate, and musculoskeletal modeling. Correlation and regression analyses assessed the relationships between ankle contributions, postural stability, and proximal joint compensations. (3) Results: Compared with the controls, the CAI group demonstrated marked control deficits during the single task (ST), characterized by reduced gait speed, increased step width, elevated mediolateral COP root mean square (COP-ml RMS), and abnormal ankle inversion and joint kinematics; these impairments were exacerbated under DT conditions. Individuals with CAI exhibited a significantly reduced ankle plantarflexion moment and energy contribution (Ankle%), accompanied by compensatory increases in knee and hip contributions. Regression analyses indicated that Ankle% significantly predicted COP-ml RMS and gait speed (GS), highlighting the pivotal role of ankle function in maintaining dynamic stability. Furthermore, CAI participants adopted a “posture-first” strategy under DT, with concurrent deterioration in gait and cognitive performance, reflecting strong reliance on attentional resources. (4) Conclusions: CAI involves global control deficits, including distal insufficiency, proximal compensation, and an inefficient energy distribution, which intensify under dual-task conditions. As the ankle is central to lower-limb kinetics, its dysfunction induces widespread instability. Rehabilitation should therefore target coordinated lower-limb training and progressive dual-task integration to improve motor control and dynamic stability. Full article

Biorobotics leverages the principles of natural locomotion to enhance the mobility of bioinspired aquatic robots. Among various swimming modes, anguilliform locomotion is particularly recognized as an energy-efficient mode incorporating complex multiphysics. Due to whole-body undulation, the determination of the anguilliform swimmer’s direction is not trivial. Furthermore, the neuromuscular mechanism that controls straight swimming is not fully understood. This study investigates the challenge of predicting and controling the gross motion trajectory of a soft robot that utilizes anguilliform swimming. The robot consists of a six-segment continuous body, where each segment is actuated with pneumatic artificial muscles. A mode extraction technique based on dynamic mode decomposition (DMD) is proposed to identify the robot’s future state. Using the complex-variable delay embedding (CDE) technique, the CDE DMD algorithm is developed to predict the robot trajectory trend. To vary the robot direction, a hypothesis that asymmetric sidewise actuation results in slightly different fluid velocities between the left and right sides of the robot was investigated using COMSOL Multiphysics^® 6.2. The simulation results demonstrate the CDE DMD’s ability to predict gross motion across various scenarios. Furthermore, integrating the prediction model with the asymmetric actuation rule provides a control strategy for directional stability of the robot. Simulations of the closed-loop system with non-zero initial pose (step response) indicate the performance in maintaining straight-line swimming with approximately a 60s settling time. Full article

This study used stair-embedded force plates to investigate the effects of lower-limb muscle fatigue on dynamic postural control during stair descent in young adults. Twenty-five healthy male adults (age = 19.2 ± 1.5 years) were tested for stair descent gait in pre-fatigue and post-fatigue conditions. To induce fatigue, participants performed a sit-to-stand task. The kinematic and kinetic data were collected synchronously, and gait parameters were analyzed. Data were analyzed using one-dimensional statistical parametric mapping (SPM1d) and paired t-tests in SPSS. After fatigue, the right knee flexion angle increased significantly across all phases (0–14%, p < 0.001; 14–19%, p = 0.032; 42–50%, p = 0.023; 60–65%, p = 0.022; 80–100%, p = 0.012). Additionally, the step width widened notably (p < 0.001), while the proportion of the swing phase decreased (p = 0.030). During the event of right-foot release, the left knee flexion (p = 0.005) and ankle dorsiflexion (p = 0.001) angle increased significantly, along with a larger left ankle plantarflexion moment (p = 0.032). After fatigue, the margin of stability in the anterior–posterior direction (MoS-AP) (p = 0.002, p = 0.014) and required coefficient of friction (RCOF) (p = 0.031, p = 0.021) significantly increased at the left-foot release and right-foot release moments. This study demonstrates that lower-limb muscle fatigue increases dynamic instability during stair descent. Participants adopted compensatory strategies, including widening step width, reducing single-support duration, and enhancing ankle plantarflexion to offset knee strength deficits. These adaptations likely reflect central nervous system mechanisms prioritizing stability, highlighting the ankle’s compensatory role as a potential target for joint-specific interventions in fall prevention and rehabilitation. Future studies should investigate diverse populations, varying fatigue levels, and comprehensive neuromuscular indicators. Full article

Purpose: The popliteus tendon (PT), though often overlooked, plays a vital role in the functional and mechanical stability of the posterolateral corner (PLC) of the knee. This narrative review consolidates the current anatomical, biomechanical, imaging, clinical, and surgical data on the PT, with an emphasis on its morphological variability and relevance in orthopedic sports medicine. Methods: A comprehensive review of the literature was conducted, including classical anatomical studies, recent classification systems, biomechanical evaluations, imaging protocols, and rehabilitation strategies. Particular focus was given to the anatomical classification proposed by Olewnik et al. and its implications in surgical and diagnostic contexts. Results: Anatomical investigations have demonstrated considerable variability in the PT, including bifid tendons and accessory fascicles. These variants have a measurable impact on preoperative planning, diagnostic imaging interpretation, and outcomes of surgical procedures, such as anterior cruciate ligament (ACL) and PLC reconstructions. The PT also contributes significantly to knee rotational control and meniscal stabilization, particularly in athletic populations. Imaging modalities, such as MRI and dynamic ultrasound, show high diagnostic utility, while arthroscopy remains the definitive diagnostic and therapeutic modality. Rehabilitation should emphasize neuromuscular re-education and progressive control of tibial rotation. A phase-based rehabilitation framework and clinical action table are proposed. Conclusions: The PT should be recognized as a critical structure in both the conservative and the surgical management of posterolateral and rotational knee instability. Enhanced awareness of its anatomical variability and functional importance can improve diagnostic accuracy, surgical precision, and clinical outcomes. In particular, MRI and high-resolution ultrasound can aid in identifying accessory fascicles and bifid tendons, while arthroscopy benefits from preoperative knowledge of PT variants to avoid misidentification and iatrogenic injury. Surgical planning for ACL and PLC reconstructions may be refined by applying the classification system described. Future research should focus on refining diagnostic algorithms, developing PT-specific functional tests, and integrating popliteus evaluation into high-level clinical decision-making and surgical navigation systems. Full article

Background/Objectives: Anterior cruciate ligament reconstruction (ACLR) necessitates evidence-based rehabilitation strategies to optimize return-to-sport (RTS) outcomes, yet persistent re-injury rates and suboptimal performance persist despite standardized protocols. The purpose of this cross-sectional observational study is to examine the relationship between biomechanical, anthropometric, and temporal factors and return-to-sport outcomes. Methods: This cross-sectional study identifies biomechanical, anthropometric, and temporal determinants of RTS readiness in 81 recreational athletes post-ACLR. Outcome measures included anterior (A-SLH), lateral (L-SLH), and medial (M-SLH) single-leg hop for distance, single-leg sit-to-stand (SLSS), single-leg wall-sit hold (SLWS), and ACL-RSI. Statistical analyses employed Spearman’s correlations and multiple linear regression to determine the predictors of ACL-RSI. Results: There were significant correlations between RSI and Limb Symmetry Index (LSI) for L-SLH, M-SLH, SLSS, and SLWS (r = 0.27, r = 0.30, r = 0.44, r = 0.34, and p < 0.01, respectively). Among the functional outcome measures, multiple linear regression revealed that only SLWS significantly predicted ACL-RSI (β = 0.248, p = 0.037). Also, body weight (β = −0.233, p = 0.030) and postoperative duration (β = 0.292, p = 0.006) significantly predicted ACL-RSI. Conclusions: These findings challenge the primacy of limb symmetry indices alone, emphasizing the role of weight management, time-dependent neuromuscular adaptation, and multi-planar closed-chain strength in RTS decision-making. Clinically, rehabilitation frameworks should integrate personalized strategies targeting body composition and dynamic stability to mitigate asymmetric joint loading and enhance functional resilience. 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

Background and Objectives: Arthrogenic muscle inhibition (AMI) is a key neurophysiological barrier to effective rehabilitation in individuals with chronic ankle instability (CAI). The primary objective of this narrative review is to explore the role of arthrogenic muscle inhibition (AMI) in chronic ankle instability (CAI) and to critically appraise neurophysiological and rehabilitative strategies targeting its resolution. Although peripheral strengthening remains a cornerstone of treatment, the roles of spinal and cortical modulation are increasingly recognised. Materials and Methods: A narrative review was conducted to examine recent clinical trials targeting AMI in CAI populations. A structured search of MEDLINE, Web of Science, Scopus, Cochrane Central, and PEDro was performed. Five studies were included, encompassing peripheral, spinal, and cortical interventions. The outcomes were grouped and analysed according to neurophysiological and functional domains. Results: Manual therapy combined with exercise improved pain, strength, and functional mobility. Fibular reposition taping transiently enhanced spinal reflex excitability, while transcranial direct current stimulation (tDCS) over the primary motor cortex significantly modulated corticospinal excitability and voluntary muscle activation. Improvements in subjective stability, dynamic balance, and neuromuscular responsiveness were observed in the majority of the five included studies, although methodological heterogeneity and short-term follow-ups limit generalisability. Conclusions: Multimodal interventions targeting different levels of the neuromotor system appear to be more effective than isolated approaches. Integrating manual therapy, sensorimotor training, and neuromodulation may optimise outcomes in CAI rehabilitation. Future trials should focus on standardised outcome measures and long-term efficacy. Full article

Gait analysis provides crucial insights into neuromuscular coordination and postural control, especially in ageing populations and rehabilitation contexts. This study investigates the complexity of muscle activation and ground reaction force patterns during gait by applying detrended fluctuation analysis (DFA) to electromyography (EMG) and force-sensitive resistor (FSR) signals. Data from a two-arm randomised clinical trial (RCT) supplemented with an observational control group were used in this study. Participants performed a single-task walking protocol, with EMG recorded from the tibialis anterior and lateral gastrocnemius muscles of both legs and FSR sensors placed under the feet. Gait cycles were segmented using heel-strike detection from the FSR signal, enabling analysis of individual strides. For each gait cycle, DFA was applied to quantify the long-range temporal correlations in the EMG and FSR time series. Results revealed consistent $\alpha$-scaling exponents across cycles, with EMG signals exhibiting moderate persistence ($\alpha \approx 0.85$–$0.92$) and FSR signals showing higher persistence ($\alpha \approx 1.5$), which is indicative of stable and repeatable gait patterns. These findings support the utility of DFA as a nonlinear signal processing tool for characterising gait dynamics, offering potential markers for gait stability, motor control, and intervention effects in populations practising movement-based therapies such as Tai Chi. Future work will extend this analysis to dual-task conditions and comparative group studies. Full article

(1) Background: Dynamic knee valgus (DKV) is a common biomechanical risk factor for knee injuries, particularly in sports involving high-intensity movements, such as basketball. While neuromuscular control and structural alignment contribute to DKV, recent evidence indicates that lower limb muscle power (LLMP) and cardiorespiratory fitness (CRF) may significantly influence DKV. This study aims to examine the relationship among LLMP, CRF, and DKV in adolescent basketball athletes. (2) Methods: A total of 104 adolescent basketball athletes (63.5% boys), 12 to 17 years old (13.87 ± 1.46 years) participated in this study. Anthropometric and demographic characteristics such as sex, age, height, weight, and body mass index (BMI) were recorded. The Counter Movement Jump (CMJ) was used for the evaluation and prediction of the LLMP, the 20 m shuttle run test (20mSRT) was used for the evaluation and prediction of CRF, and the single-leg drop jump (SLDJ) was used for the evaluation of DKV via a two-dimensional (2D) kinematic analysis. Statistical analysis included Pearson and Spearman correlations, as well as multiple linear regression, to determine the relationship among LLMP, CRF, and DKV. (3) Results: A statistical analysis revealed strong correlations among LLMP, CRF, and DKV. Pearson’s correlation coefficients demonstrated significant associations between the VO₂max and frontal plane projection angle (FPPA) (r = 0.78, p < 0.001), as well as between LLMP and FPPA (r = 0.82, p < 0.001). Multiple linear regression analysis showed that VO₂max and LLMP together accounted for 85% of the variance in FPPA (R² = 0.85, p < 0.001). (4) Conclusions: The findings highlight that both aerobic capacity and lower limb muscle power significantly contribute to knee valgus control among adolescent basketball players. Implementing training programs focused on improving lower limb muscle power and cardiorespiratory fitness may enhance knee stability and reduce the risk of lower limb injuries. Given the strong predictive value of VO₂max and LLMP for knee control, targeted training programs focusing on neuromuscular conditioning and aerobic capacity may be effective for injury prevention. Full article