Search Results (199)

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

The Bayesian Hurst–Kolmogorov (HK) method estimates the Hurst exponent of a time series more accurately than the age-old Detrended Fluctuation Analysis (DFA), especially when the time series is short. However, this advantage comes at the cost of computation time. The computation time increases exponentially with the time series length N, easily exceeding several hours for $N=1024$, limiting the utility of the HK method in real-time paradigms, such as biofeedback and brain–computer interfaces. To address this issue, we have provided data on the estimation accuracy of the Hurst exponent H for synthetic time series as a function of a priori known values of H, the time series length, and the simulated sample size from the posterior distribution n—a critical step in the Bayesian estimation method. The simulated sample from the posterior distribution as small as $n=25$ suffices to estimate H with reasonable accuracy for a time series as short as 256. Using a larger simulated sample from the posterior distribution—that is, $n>50$—provides only a marginal gain in accuracy, which might not be worth trading off with computational efficiency. Results from empirical time series on stride-to-stride intervals in humans walking and running on a treadmill and overground corroborate these findings—specifically, allowing reproduction of the rank order of $\widehat{H}$ for time series containing as few as 32 data points. We recommend balancing the simulated sample size from the posterior distribution of H with the user’s computational resources, advocating for a minimum of $n=50$. Larger sample sizes can be considered based on time and resource constraints when employing the HK process to estimate the Hurst exponent. The present results allow the reader to make judgments to optimize the Bayesian estimation of the Hurst exponent for real-time applications. Full article

Falls are the leading cause of injury and mortality among older adults—one in four individuals 65 years old and above experiences falls. Thus, balance training interventions that improve balance ability and reduce the risk of falls are of critical importance. Through two complementary interventions, our research sought to determine the effects of Virtual Reality (VR) compared to Robotic-Assisted Balance Training (RABT) on balance ability and balance confidence in older adults. The VR intervention utilized Oculus headsets to create immersive balance exercises, while the RABT employed a multidirectional overground robotic system (NaviGAITor). Participants (aged 60–85 years old) underwent a 6-week training protocol consisting of two 30 min sessions per week. Balance ability was quantified using center of pressure (COP) parameters and the Balance Error Scoring System (BESS), while balance confidence was measured using the Activities-Specific Balance Confidence (ABC) scale. Results indicated no statistically significant differences between the training methods. However, the RABT group showed trends toward enhanced balance performance, with observed decreases in mediolateral (ML) maximum displacement during wide stance conditions and reductions in BESS errors on both firm and foam surfaces. The VR group demonstrated significant changes in ML RMS values during tandem stance (p = 0.045) and improved participants’ relationship with perceived and actual balance ability (increased correlation between BESS errors and ABC scores from R² = 0.00 pre-training to R² = 0.65 post-training). Balance confidence did not significantly increase in either group. These findings suggest that while RABT may trend toward improvements in objective balance parameters, VR training appears to enhance participants’ perceptual accuracy of their balance capabilities. Full article

The surface properties of the running surface have an effect on physiological and biomechanical responses to exercise, but their influence on body composition, blood pressure, and knee joint kinetics during controlled sports loading is less researched. This study compared the effects of treadmill running (TR) and overground running (OR) on acute physiological and biomechanical adaptation in ten male athletes aged between 23 and 26 years old following a 30 min protocol at 75% VO₂max. Pre- and post-running body composition (fat volume, protein content, and fluid distribution), blood pressure, and knee joint kinetics (total work of muscle extensors—TWMEs) were assessed using bioelectrical impedance analysis, blood pressure monitor, and isokinetic dynamometry. The results indicated that TR led to highly significant reductions in protein content with a considerable accumulation of intracellular fluid. At the same time, TR reduced knee TWME by 27.4%, and OR elevated TWME by 5.6%. No significant differences in blood pressure were observed. These findings highlight surface-specific metabolic stress and biomechanical loading patterns and show that TR augments catabolic responses and knee joint strain despite equivalent external workloads. Full article

Robotic walking assistance devices support the rehabilitation of patients with neurological impairments. However, most commercialized systems rely on treadmill-based walking, which may not reflect real-world environments. This study aimed to evaluate the usability of a newly developed over-ground walking assistance robot (OWAR-MW) based on mecanum wheels compared with a commercial system (Andago) from the perspectives of physical therapists and patients with stroke. Nine physical therapists and nine stroke patients participated. Each participant walked 100 m using both the OWAR-MW and Andago systems. Subsequently, a satisfaction survey was conducted across three categories—safety, operability and functionality, and convenience—using a questionnaire adapted from the standard usability testing guidelines for walking assistive devices. Additionally, in-depth interviews were conducted to explore user experience and improvement needs. In both participant groups, the OWAR-MW showed a tendency for lower satisfaction scores than Andago across all categories. Stroke patients reported significantly lower scores in all three categories (safety: 4.90 vs. 4.04, operability and functionality: 4.83 vs. 4.33, convenience: 4.87 vs. 4.49, p < 0.05), whereas therapists noted a significant difference only in safety (4.02 vs. 3.37, p < 0.05). Key issues identified included a lack of handles, delay in actuator response, low motion detection sensitivity, non-intuitive controls, and discomfort caused by the harness, particularly the thigh straps. OWAR-MW demonstrated usability limitations in its current prototype form. Technical improvements in user interface, control accuracy, and harness design are necessary before clinical application. This study provides valuable feedback for the future development of user-centered rehabilitation robotics. Full article

In equine surface electromyography (sEMG), challenges related to the reliability and interpretability of data arise, among other factors, from methodological differences, including signal processing and analysis. The aim of this study is to demonstrate the filtering–induced changes in basic signal features in relation to the balance between signal loss and noise attenuation. Raw sEMG signals were collected from the quadriceps muscle of six horses during walk, trot, and canter and then filtered using eight filtering methods with varying cut–off frequencies (low–pass at 10 Hz, high–pass at 20 Hz and 40 Hz, and bandpass at 20–450 Hz, 40–450 Hz, 7–200 Hz, 15–500 Hz, and 30–500 Hz). For each signal variation, signal features—such as amplitude, root mean square (RMS), integrated electromyography (iEMG), median frequency (MF), and signal–to–noise ratio (SNR)—along with signal loss metrics and power spectral density (PSD), were calculated. High–pass filtering at 40 Hz and bandpass filtering at 40–450 Hz introduced significant filtering–induced changes in signal features while providing full attenuation of low–frequency noise contamination, with no observed differences in signal loss between these two methods. Other filtering methods led to only partial attenuation of low–frequency noise, resulting in lower signal loss and less consistent changes across gaits in signal features. Therefore, filtering–induced changes should be carefully considered when comparing signal features from studies using different filtering approaches. These findings may support cross-referencing in equine sEMG research related to training, rehabilitation programs, and the diagnosis of musculoskeletal diseases, and emphasize the importance of applying standardized filtering methods, particularly with a high–pass cut–off frequency set at 40 Hz. Full article

In order to investigate the stage plant architecture and productivity characteristics of different cucumber varieties and pruning methods and to construct a comprehensive productivity evaluation system based on plant architecture parameters, this study used JY35 and JS206 as experiment materials and conducted a dual factor control experiment with variety and pruning methods (single-stem pruning (SP) and natural growth (NG)) to systematically analyze the key phenotypic characteristics and productivity indicators of cucumbers at different developmental stages based on variance analysis and principal component evaluation. The results indicated the following: (1) Varieties and pruning methods have a significant impact on the plant architecture characteristics and productivity indicators. (2) The dominant plant architecture characteristics and productivity indicators of JY35 include dry and fresh weights of the tendril, main stem, total stem, leaves, petioles, flowers, overground parts, and overall plant, as well as dry and fresh weight distribution index of the tendril, total stem, leaves, petioles, flowers, overground parts, and overall plant, main stem fresh weight distribution index, water content of roots, tendrils, main stem, leaves, petioles, and flowers, volume of total stem, main stem, and petioles, plant height, total leaf area per plant, leaf area index, and specific leaf area. The remaining plant architecture characteristics and productivity indicators are dominated by the plant architecture of JS206. (3) The dominant plant architecture characteristics and productivity indicators of the SP method include dry and fresh weight distribution index of roots, fruit carpopodiums, main stems, and total stems, water content of petioles, stems, and leaves, and root-to-shoot ratio. The remaining plant architecture characteristics and productivity indicators are dominated by the NG method. This study quantified the dynamic correlation between cucumber plant architecture and productivity characteristics, and the research results can provide a morphological basis for facility cucumber variety breeding and theoretical support for optimizing pruning cultivation mode and achieving efficient utilization of light and heat resources. Full article

Background: Defined as a self-selected speed of <0.4 m/s, chronic stroke survivors falling in this category are classified as “severe”, usually homebound and sedentary, and they experience worse outcomes. Limited rehabilitation strategies are available to improve walking speed and related outcomes in this subgroup, and questions regarding effective rehabilitation options remain. The objective of this study was to determine the effects of backward (BLTT) and forward (FLTT) locomotor treadmill training on overground walking speed, spatiotemporal symmetry, and dynamic postural stability. Methods: In this single-center, assessor-blinded, randomized controlled pilot trial, 14 stroke survivors with severe waking impairment underwent 12 sessions of BLTT (n = 7) or FLTT (n = 7). The primary outcome was the proportion of participants reaching clinically meaningful important difference (MCID) on the 10-meter walk test following training completion. Secondary outcomes were between-group differences in walking speed, spatiotemporal symmetry, and completion time on the 3-meter timed up and go (3M TUG) at 24 h, 30 days, and 90 days POST. Results: Two subjects in the BLTT group (28.6%) and one (14.3%) in FLTT achieved MCID following training; however, most subjects did not, with significant variability in response. At 24 h POST, the median (IQR) percent change in walking speed was 28.9 (9.01–36.7) and 17.4 (12.6–39.7) with BLTT and FLTT, respectively; however, no between-group differences were seen (p = 0.80) at this time point or at 30 (p > 0.99) and 90 (p > 0.99) days follow up. Likewise, there were no significant between-group differences in spatiotemporal symmetry and the 3M TUG across time points. Conclusions: While preliminary, this study found that 12 training sessions did not lead to group-level achievement of MCID for walking speed in our cohort and found no significant between-group differences in walking capacity or dynamic postural stability. Future well-powered dosing trials and mechanistically driven studies are needed to optimize and identify predictors of training response. Full article

Objectives: Gait kinematic and kinetic changes have been identified in older adults, highlighting the need to explore the principal age-related components and how these are associated with functional disability. This study aims to perform a factor analysis, including gait kinematic and kinetic parameters in older adults to establish determinant gait domains. Additionally, this study aims to identify which domains differentiate those without and with functional disability. Methods: Through a cross-sectional design, older adults aged 60 and over (n = 35 without and n = 25 with functional disability) were analyzed during overground gait. A principal component analysis (PCA) was used to determine principal components from gait parameters previously demonstrated to express age-related effects (spatiotemporal parameters, sagittal ankle moment and power, ground reaction forces peak, and tridimensional lower limb joints range of motion and positions at heel strike and toe-off). Results: Pace, variability, propulsion, hip and knee control, transverse ankle control, asymmetry, sagittal ankle control, frontal ankle control, frontal hip control, and pre-swing control domains explained 83.90% of the total gait variance in older adults. pace and frontal hip control distinguished individuals with disabilities. Conclusions: PCA identified ten gait domains in older adults. Pace and frontal hip control distinguished disabilities, revealing cautious walking patterns and weaker hip abductor strength. Full article

Introduction: Implanted spinal cord epidural stimulation (SCES) is an emerging neuromodulation approach that increases the excitability of the central pattern generator [CPG] and enhances tonic and rhythmic motor patterns after spinal cord injury (SCI). We determine the effects of exoskeleton-assisted walking [EAW] + epidural stimulation [ES] + resistance training [RT] on volitional motor control as a primary outcome, as well as autonomic cardiovascular profile, body composition, and bladder function compared to EAW + delayed ES + noRT in persons with motor-complete SCI AIS A and B. Methods and Analysis: Twenty male and female participants [age 18–60 years] with traumatic motor-complete SCI [2 years or more post injury], and level of injury below C5 were randomized into either EAW + ES + RT or EAW + delayed-ES + no-RT groups for more than 12 months. Baseline, post-interventions 1 and 2 were conducted six months apart. Measurements included body composition assessment using anthropometry, dual x-ray absorptiometry, and magnetic resonance imaging prior to implantation to evaluate the extent of spinal cord damage, neurophysiologic assessments to record H-reflexes, overground ambulation and peak torque for both groups, and the Walking Index for Spinal Cord Injury Scale [WISCI 2]. Metabolic profile measurements included the resting metabolic rate, fasting biomarkers of HbA1c, lipid panels, total testosterone CRP, IL-6, TNF-α, plasma IGF-I, IGFBP-3, and then a glucose tolerance test. Finally, urodynamic testing was conducted to assess functional bladder improvement due to ES. Results: The restoration of locomotion with ES and EAW may result in a reduction in psychosocial, cardiovascular, and metabolic bladder parameters and socioeconomic burden. The addition of the resistance training paradigm may further augment the outcomes of ES on motor function in persons with SCI. Conclusions: Percutaneous SCES appears to be a feasible and safe rehabilitation approach for the restoration of motor function in persons with SCI. The procedure may be successfully implemented with other task-specific training similar to EAW and resistance training. Full article

Obstacle circumvention is an important task for community ambulation that is challenging to replicate in research and clinical environments. Omnidirectional treadmills combined with virtual reality (ODT-VR) offer a promising solution, allowing users to change walking direction and speed while walking in large, simulated environments. However, the extent to which such a setup yields circumvention strategies representative of overground walking in the real world (OVG-RW) remains to be determined. This study examined obstacle circumvention strategies in ODT-VR versus OVG-RW and measured how they changed with practice. Fifteen healthy young individuals walked while avoiding an interferer, performing four consecutive blocks of trials per condition. Distance at onset trajectory deviation, minimum distance from the interferer, and walking speed were compared across conditions and blocks. In ODT-VR, larger clearances and slower walking speeds were observed. In contrast, onset distances and proportions of right-side circumvention were similar between conditions. Walking speed increased from the first to the second block exclusively. Results suggest the use of a cautious locomotor behavior while using the ODT-VR setup, with some key features of circumvention strategies being preserved. Although ODT-VR setups offer exciting prospects for research and clinical applications, consideration should be given to the generalizability of findings to the real world. Full article

This study assessed the effect of filter parameters on gait characteristics and the performance of machine-learning models. Overground walking trials (n = 99) with and without perturbations (slips, trips) were collected for 33 healthy older adults. Kinematics were collected by a motion capture system. Different Butterworth low-pass parameters were applied to the raw data, including three orders (2–6) and nine cutoffs (4–20 Hz). Spatiotemporal gait outcomes were then calculated to develop classification models to automatically identify the trial type (gait, gait–slip, or gait–trip) using Logistic Regression, Support Vector Classification, and Random Forest Classification. A 3 × 9 ANOVA showed main effects of order and cutoff (p < 0.01 for all) on gait characteristics during both perturbed and regular walking trials. However, the gait characteristics were different between them. The filter parameters significantly affected the performance of classification models using different classifiers, with significant main effects of the filter order (p < 0.05) and cutoff (p < 0.01) on AUC and overall accuracy for all of the models. Our results suggest that the standard Butterworth filter (fourth-order, cutoff: 6 Hz) is suitable for the development of classification models with low–medium complexity, while for models with high complexity (i.e., ensemble models), a filter with a higher order and cutoff (sixth-order, cutoff 10–12 Hz) might yield better performance. Full article

Background: Exoskeletons are used in rehabilitation centers for people with spinal cord injuries (SCI) due to the potential benefits they offer for locomotor rehabilitation. The acceptability of exoskeletons is crucial to promote rehabilitation and to ensure a successful implementation of this technology. The objective was to explore the acceptability of overground wearable powered exoskeleton used in rehabilitation among people with SCI. Methods: Fourteen individuals with SCI (9 men, mean [SD] age 47 years [14.8], a majority with traumatic and thoracic lesion (T6–T12)) who had utilized an exoskeleton in Canada or in France during their rehabilitation participated in a semi-structured interview. A thematic analysis using the theoretical framework of acceptability was carried out. Results: Participants were motivated to use an exoskeleton during their rehabilitation. They reported several perceived benefits to its use, including better walking pattern, increased endurance, and greater muscle mass. They also experienced mild pain, notable concentration demands, and fatigue. Most participants reported that using exoskeletons in their rehabilitation process was appropriate and relevant to them. Conclusions: Exoskeletons are generally well accepted by participants in this study. Adjustments in their use, such as conducting training sessions in obstacle-free environment and technological improvements to address the device’s restrictive characteristics, heaviness, and massiveness are however still needed. Full article

Background: Accurate linear sprint modelling is essential for evaluating athletes’ performance, particularly in terms of force, power, and velocity capabilities. Radar sensors have emerged as a critical tool in capturing precise velocity data, which is fundamental for generating reliable force-velocity (FV) profiles. This study focuses on the fitting of radar sensor data to various sprint modelling techniques to enhance the accuracy of these profiles. Forty-seven university-level athletes (M = 23, F = 24; 1.75 ± 0.1 m; 79.55 ± 12.64 kg) participated in two 40 m sprint trials, with radar sensors collecting detailed velocity measurements. This study evaluated five different modelling approaches, including three established methods, a third-degree polynomial, and a sigmoid function, assessing their goodness-of-fit through the root mean square error (RMSE) and coefficient of determination (r²). Additionally, FV metrics (P_max, F₀, V₀, FV_slope, and DRF) were calculated and compared using ANOVA. Results: Significant differences (p < 0.001) were identified across the models in terms of goodness-of-fit and most FV metrics, with the sigmoid and polynomial functions demonstrating superior fit to the radar-collected velocity data. Conclusions: The results suggest that radar sensors, combined with appropriate modelling techniques, can significantly improve the accuracy of sprint performance analysis, offering valuable insights for both researchers and coaches. Care should be taken when comparing results across studies employing different modelling approaches, as variations in model fitting can impact the derived metrics. Full article

Background and Purpose: activities-based locomotor training (AB-LT) is a restorative therapeutic approach to the treatment of movement deficits in people with non-progressive neurological conditions, including cerebral palsy (CP). Transcutaneous spinal stimulation (TSS) is an emerging tool in the rehabilitation of individuals with sensorimotor deficits caused by neurological dysfunction. This non-invasive technique delivers electrical stimulation over the spinal cord, leading to the modulation of spinal sensorimotor networks. TSS has been used in combination with AB-LT and has been shown to improve muscle activation patterns and enhance motor recovery. However, there are no published studies comparing AB-LT + TSS to AB-LT alone in children with CP. The purpose of this case study was to compare the impact of AB-LT alone versus AB-LT combined with TSS on functional movement and quality of life in a child with CP. Methods: A 13-year-old male with quadriplegic CP participated in this pilot study. He was classified in the Gross Motor Function Classification System (GMFCS) at Level III. He completed 20 sessions of AB-LT (5x/week), then a 2-week washout period, followed by 20 sessions of body-AB-LT + TSS. Treatment sessions consisted of 1 h of locomotor training with body weight support and manual facilitation and 30 min of overground play-based activities. TSS was applied using the RTI Xcite^®, with stimulation at the T11 and L1 vertebral levels. Assessments including the Gross Motor Function Measure (GMFM), 10-m walk test (10 MWT), and Pediatric Balance Scale (PBS) were performed, while spatiotemporal gait parameters were assessed using the Zeno Walkway^®. All assessments were performed at three time points: before and after AB-LT, as well as after AB-LT + TSS. OUTCOMES: After 19/20 sessions of AB-LT alone, the participant showed modest improvements in the GMFM scores (from 86.32 to 88), 10 MWT speed (from 1.05 m/s to 1.1 m/s), and PBS scores (from 40 to 42). Following the AB-LT combined with TSS, scores improved to an even greater extent compared with AB-LT alone, with the GMFM increasing to 93.7, 10 MWT speed to 1.43 m/s, and PBS to 44. The most significant gains were observed in the GMFM and 10 MWT. Additionally, improvements were noted across all spatiotemporal gait parameters, particularly at faster walking speeds. Perhaps most notably, the child transitioned from the GMFCS level III to level II by the end of the study. Discussion: Higher frequency and intensity interventions aimed at promoting neuroplasticity to improve movement quality in children with CP are emerging as a promising alternative to traditional physical therapy approaches. This case study highlights the potential of TSS to augment neuroplasticity-driven treatment approaches, leading to improvements in neuromotor function in children with CP. These findings suggest that TSS could be a valuable addition to rehabilitation strategies, warranting further research to explore its efficacy in larger populations. Full article