Gait Analysis with an Upper Limb Prosthesis in a Child with Thrombocytopenia-Absent Radius Syndrome.

The present study evaluated gait asymmetry in elite runners by quantifying the differences between ground contact times (GCTs) of the right and left foot and its continuous changes over the course of a 5-km time trial on a 400-m synthetic track. By means of the inertial sensor Axiamote, the GCT of every step was assessed. The results revealed an overall gait asymmetry of 2.6%, but no changes in gait asymmetry over the course of the 5-km time trial. On the bend, the GCTs of the left foot were significantly (p < .001) longer than the GCTs of the right foot, whereas no such differences were reported on the straight section. However, gait asymmetry remained the same for both the straight and bend Sects. (2.7 vs. 2.8%). Overall, no gender differences regarding gait asymmetry occurred. In conclusion, a low and consistent gait asymmetry between GCTs of both feet in male and female runners was observed.

Gait deficits greatly contribute to functional disability after stroke; of all stroke-related impairments, improvement of walking function is the goal most often stated by patients.1 Therefore, gait is a primary focus of physiotherapy intervention post-stroke. Most of the research on post-stroke gait focuses on velocity or endurance. By contrast, temporal and spatial symmetry (although not new to clinical practice) receive relatively less attention. To date, most studies have only reported symmetry values. Very few studies have included gait symmetry as their main focus, and fewer still have attempted to understand the underlying mechanisms of asymmetry.2 Post-stroke gait asymmetry is the main focus of the study by Beauchamp et al. in this issue of Physiotherapy Canada.3 More specifically, the investigators examined the immediate effects of cane use on the symmetry of patients with stroke in the subacute stage. According to their results, a standard cane, but not a quad cane, improves symmetry in individuals with an asymmetrical gait pattern.3 By contrast, there was no observed effect of cane use in those patients with a symmetrical gait pattern.3 The study by Beauchamp et al. illustrates two important issues relevant to clinical practice and research in stroke rehabilitation. First, it demonstrates the value of categorizing patients with stroke in finer detail than is possible using velocity or a measure of motor impairment, such as the Chedoke-McMaster Stroke Assessment (CMSA), alone. Typical gait deficits associated with stroke include decreased velocity, increased step variability, increased or decreased joint displacement, and altered EMG timing and amplitude.4 Although any given individual with stroke will likely display some unique combination of the common deviations described above, he or she is unlikely to display all the deviations. More simply, no two persons with stroke are alike. This presents a challenge for both clinicians and researchers. For clinicians, no one therapeutic approach will be appropriate for all patients. Developing a method for classification of individuals with stroke that uses a composite of key measurements (e.g., velocity, gait variability, and gait symmetry as well as motor impairment) will assist the clinician in designing physiotherapy programs tailored to the individual patient. For researchers, results can be attenuated by an averaging effect of responders and non-responders within a study sample. A priori classification of study participants can circumvent this challenge, as Beauchamp et al.’s study clearly demonstrates. Using gait symmetry as the basis for categorization, the authors were able to demonstrate the effects of cane use in a subset of the subjects they recruited, something previous studies were unable to show.3 The second important point highlighted by Beauchamp et al. is the issue of gait asymmetry itself. Considerable attention has been focused on the measurement and improvement of gait velocity post-stroke. As a clinical measure, velocity reflects overall performance; however, it is limited in its value to document post-stroke recovery. In addition, velocity provides no information on the underlying impairments contributing to gait dysfunction.5,6 Gait symmetry is a complementary measure that may reflect the quality of gait. Brandstater et al.7 suggested that symmetry may characterize post-stroke gait better than unilateral values. In addition to its value as a clinical gait measure, asymmetry is an important issue to address therapeutically because of its possible negative consequences, which include increased challenge to balance control, increased energy expenditure during walking, and negative impact on the musculoskeletal health of the non-paretic limb.8 In addition, individuals post-stroke may decrease their overall activity levels, over time, in response to any one or combination of these factors.8 In light of these possible effects, gait asymmetry should be addressed by post-stroke gait rehabilitation programs. A commonly identified barrier to taking objective, quantitative measures of gait (such as gait symmetry) in the clinical setting is cost. The Beauchamp et al. study measured spatiotemporal gait parameters using the GAITRite mat, which costs approximately $17,000. At first, this seems expensive; however, the average treadmill and body-weight support (BWS) system costs $27,000, and this equipment is more readily adopted in the clinical setting. It is more informative to discuss cost–benefit trade-offs than to rely on cost alone. Clinicians perceive a benefit to patients and their practice from the BWS treadmill, and thus the cost of purchasing the equipment is outweighed by its positive effects on patient gait. Once we have established the value of objective, quantitative gait measurements, including symmetry, to clinical practice, purchasing the equipment necessary to provide these measurements will also seem like a sound decision. Furthermore, a clinical community more focused on objective, quantitative measures of gait would further stimulate the development and commercialization of new, simple, and cost-effective measurement solutions.8 In order to establish the value of measuring and treating post-stroke gait asymmetry, more research is needed. The goal of most post-stroke gait research is to examine or improve velocity, endurance, or both. Measurement or improvement of gait symmetry is rarely the primary focus, with a few exceptions.9–11 The study by Beauchamp et al. is the latest of a small number of studies to focus on gait symmetry, potentially a more important gait outcome, given its associated negative consequences. According to their results, use of a cane may be one approach to ameliorate asymmetry in the subacute stroke population. Their findings complement research presently under way examining the feasibility of visual biofeedback during treadmill walking as another intervention to improve gait symmetry.12 There is a need for more research in this area. As outlined by Beauchamp et al., the clinically meaningful change in symmetry needs to be established.3 Other important research areas are the following: Determination of a threshold for symmetry: What degree of asymmetry is associated with the possible negative consequences outlined above? Determination of the underlying causes of asymmetry: although motor impairment is associated with gait symmetry, as Beauchamp et al. describe, it does not explain all of the variance observed in the stroke population. Furthermore, our work has revealed that individuals with the same level of motor impairment, as measured by the CMSA, can have different degrees of asymmetry.8 Understanding the underlying causes of asymmetry will assist in the development of rehabilitation programs that promote symmetrical gait. Examination of the effectiveness of rehabilitation protocols for gait symmetry.

Study aim: Backpack carriage is a daily necessity for school-going children, but excessive loads and prolonged carrying durations may disrupt gait mechanics, potentially leading to musculoskeletal strain. The present study aimed to analyse the effect of progressive backpack weights and carrying durations on the contact time during the walking gait of school-aged boys. Additionally, it assessed the symmetry between left and right foot contact times under varying conditions. Material and methods: A total of 85 healthy male students (mean age = 11.06 ± 0.76 years, height 143.50 ± 5.11 cm, body weight 36.00 ± 4.05 kg) from Delhi National Capital Region participated in the study. Contact time was recorded using the Zebris FDM pressure plate under five backpack weights (0%, 8%, 12%, 16%, and 20% of body weight) and five intervals (0, 5, 10, 15, and 20 minutes). A 5 × 5 repeated measures design was used. Descriptive statistics, paired-sample t-tests and two-way repeated measures ANOVA were employed to evaluate the effects of backpack weight and duration. Results: Progressive backpack weights up to 12% of body weight increased contact time, reflecting biomechanical adjustments to maintain stability. However, loads of 16% and above caused fatigue, disrupting gait patterns. Prolonged carrying durations intensified these effects, leading to greater variability and asymmetry in contact time, particularly under heavier loads. Significant differences in contact time between the left and right foot were observed (p &lt; 0.05), indicating uneven weight distribution and compensatory gait strategies. ANOVA findings confirmed a significant main effect of backpack weight, a significant interaction between weight and duration, and a statistically significant main effect of duration for the left foot. Conclusions: The findings suggest that excessive backpack weight and prolonged carrying duration significantly alter foot contact time and gait symmetry, which may contribute to musculoskeletal stress in school-aged children. A threshold effect emerged, where both backpack weight and duration—independently and interactively—disrupted natural gait stability, particularly in the non-dominant limb. The study supports limiting backpack weight to 10–12% of body weight and reducing prolonged carriage duration. Future studies should incorporate multifactorial models and longitudinal tracking to better understand the long-term impact of load-induced gait adaptations.

Movement and loading asymmetry are associated with an increased risk of musculoskeletal injury, disease progression, and suboptimal recovery. Osteopathic structural screening can be utilized to determine areas of somatic dysfunction that could contribute to movement and loading asymmetry. Osteopathic manipulation treatments (OMTs) targeting identified somatic dysfunctions can correct structural asymmetries and malalignment, restoring the ability for proper compensation of stresses throughout the body. Little is currently known about the ability for OMTs to reduce gait asymmetries, thereby reducing the risk of injury, accelerated disease progression, and suboptimal recovery. To demonstrate whether osteopathic screening and treatment could alter movement and loading asymmetry during treadmill walking. Forty-two healthy adults (20 males, 22 females) between the ages of 18 and 35 were recruited for this prospective intervention. Standardized osteopathic screening exams were completed by a single physician for each participant, and osteopathic manipulation was performed targeting somatic dysfunctions identified in the screening exam. Three-dimensional (3-D) biomechanical assessments, including the collection of motion capture and force plate data, were performed prior to and following osteopathic manipulation to quantify gait mechanics. Motion capture and loading data were processed utilizing Qualisys Track Manager and Visual 3D software, respectively. Asymmetry in the following temporal, kinetic, and kinematic measures was quantified utilizing a limb symmetry index (LSI): peak vertical ground reaction force, the impulse of the vertical ground reaction force, peak knee flexion angle, step length, stride length, and stance time. A 2-way repeated-measures analysis of variance model was utilized to evaluate the effectsof time (pre/post manipulation) and sex (male/female) on each measure of gait asymmetry. Gait asymmetry in the peak vertical ground reaction force (-0.6%, p=0.025) and the impulse of the vertical ground reaction force (-0.3%, p=0.026) was reduced in males following osteopathic manipulation. There was no difference in gait asymmetry between time points in females. Osteopathic manipulation did not impact asymmetry in peak knee flexion angle, step length, stride length, or stance time. Among the participants, 59.5% (25) followed the common compensatory pattern, whereas 40.5% (17) followed the uncommon compensatory pattern. One third (33.3%, 14) of the participants showed decompensation at the occipitoatlantal (OA) junction, whereas 26.2% (11), one third (33.3%, 14), and 26.2% (11) showed decompensation at the cervicothoracic (CT), thoracolumbar (TL), and lumbosacral (LS) junctions, respectively. Somatic dysfunction at the sacrum, L5, right innominate, and left innominate occurred in 88.1% (37), 69.0% (29), 97.6% (41), and 97.6% (41) of the participants, respectively. Correcting somatic dysfunction can influence gait asymmetry in males; the sex-specificity of the observed effects of osteopathic manipulation on gait asymmetry is worthy of further investigation. Osteopathic structural examinations and treatment of somatic dysfunctions may improve gait symmetry even in asymptomatic individuals. These findings encourage larger-scale investigations on the use of OMT to optimize gait, prevent injury and the progression of disease, and aid in recovery after surgery.

Background and objectives: Cerebral palsy (CP) is the most frequent childhood motor disability. Achieving ambulation or standing in children with CP has been a major goal of physical therapy. Recently, robot-assisted gait training using the Hybrid Assistive Limb® (HAL) has been effective in improving walking ability in patients with CP. However, previous studies have not examined in detail the changes in gait pattern after HAL training for patients with spastic CP, including gait symmetry. This study aimed to evaluate the immediate effect of HAL training on the walking ability and the changes in gait pattern and gait symmetry in patients with spastic CP. Materials and Methods: We recruited 19 patients with spastic CP (13 male and six female; mean age, 15.7 years). Functional ambulation was assessed using the 10-Meter Walk Test and gait analysis in the sagittal plane before and after a single 20-min HAL intervention session. Results: The walking speed and stride length significantly increased after HAL intervention compared to the pre-intervention values. Two-dimensional gait analysis showed improvement in equinus gait, increase in the flexion angle of the swing phase in the knee and hip joints, and improvement in gait symmetry. Immediate improvements in the walking ability and gait pattern were noted after HAL training in patients with spastic CP. Conclusions: The symmetry of the joint angle of the lower limb, including the trunk, accounts for the improvement in walking ability after HAL therapy.

Movement asymmetries during walking are common after anterior cruciate ligament (ACL) injury and reconstruction and may influence the early development of posttraumatic osteoarthritis. Preoperative neuromuscular training (like perturbation training, which is neuromuscular training requiring selective muscle activation in response to surface perturbations) improves gait asymmetries and functional outcomes among people who are ACL-deficient, but the effect of postoperative perturbation training on gait mechanics after ACL reconstruction is unknown. Among men undergoing ACL reconstruction, we sought to compare strength, agility, and secondary prevention (SAP) treatment with SAP plus perturbation training (SAP+PERT) with respect to (1) gait mechanics; and (2) elimination of gait asymmetries 1 and 2 years after ACL reconstruction. Forty men were randomized into a SAP group or a SAP+PERT group after ACL reconstruction and before returning to preinjury activities. Participants were required to achieve ≥ 80% quadriceps muscle strength symmetry, minimal knee effusion, full ROM, no reports of pain, andcompletion of a running progression (all between 3 and 9 months postoperatively) before enrollment. Of 94 potentially eligible athletic male patients evaluated < 9 months after ACL reconstruction, 54 were excluded for prespecified reasons. Participants underwent motion analysis during overground walking at 1 and 2 years postoperatively. Variables of interest included (1) sagittal and frontal plane hip and knee angles and moments at peak knee flexion angle; (2) sagittal plane hip and knee angles and moments at peak knee extension angle; (3) sagittal plane hip and knee excursion during weight acceptance; and (4) sagittal plane hip and knee excursion during midstance. We also calculated the proportion of athletes in each group who walked with clinically meaningful interlimb asymmetry in sagittal plane hip and knee variables and compared these proportions using odds ratios. There was no differential loss to followup between groups. There were no differences between the SAP or SAP+PERT groups for the biomechanical gait variables. The involved limb's knee excursion during midstance for the SAP (mean ± SD: 1 year: 15° ± 5°; 2 years: 16° ± 5°) and SAP+PERT (1 year: 16° ± 5°; 2 years: 15° ± 4°) athletes was not different between groups at 1 year (mean difference: -1°; 95% confidence interval [CI], -5° to 2°; p = 0.49) or 2 years (mean difference: 1°; 95% CI, -2° to 4°; p = 0.54). There were no differences between SAP and SAP+PERT athletes regarding the elimination of gait asymmetries, and gait asymmetries persisted to a large degree in both groups 1 and 2 years postoperatively. At 1 year, 11 of 18 SAP and 11 of 20 SAP+PERT athletes walked with truncated knee excursions during weight acceptance (odds ratio: 0.8, p = 0.70) and midstance (SAP 12 of 18, SAP+PERT 12 of 20; odds ratio: 0.8, p = 0.67), whereas at 2 years postoperatively, truncated knee excursions during weight acceptance (SAP seven of 17, SAP+PERT eight of 19; odds ratio: 1.0, p = 0.96) and midstance (SAP five of 17, SAP+PERT 11 of 19; odds ratio: 3.3, p = 0.09) remained prevalent. We found that a comprehensive, progressive return-to-sport training program with or without perturbation was not effective at restoring interlimb symmetry among men 1 or 2 years after ACL reconstruction. Although gait asymmetries improved from 1 to 2 years postoperatively, meaningful asymmetries persisted in both groups. To restore gait symmetry after ACL reconstruction, additional interventions likely are necessary. Level II, therapeutic study.

Thanks to the progress in the robotic and mechatronic fields, upper limb prostheses became more and more dexterous, getting closer to closing the gap between the natural limb and the medical device replacing it. However, the standard prosthesis controller spread on the market is still limited in the number of functions it can efficiently control and constitute a bottleneck in prosthesis use. Two leading solutions are currently under research to tackle this discrepancy: machine learning algorithms and autonomous controllers. Myo-controllers based on machine learning algorithms enable the user to control a high but still limited number of functions directly. On the other hand, autonomous controllers are based on a diversification of the sensor modalities to integrate the context and the user's intention in control and automatise part of the grasping process, relieving the user from the physical and potentially cognitive workload associated with it. This thesis focuses on the impact of the combination of these two solutions. Therefore, two studies investigated the gain of performance gain and the range of applicability of an association of a semi-autonomous system to a machine learning myo-controller for upper limb prostheses. This dissertation introduces first a method to preshape the prosthesis based on the prediction of the user’s intended grasping strategy. This method system supports the user in real-time by preshaping the prosthetic device's hand and wrist during a reaching phase of a prehensile action. This result is achieved by merging data from inertial measurement units, computer vision, and positions and pressure sensors to reproduce artificial proprioception, artificial exteroception, and short-term memory. The autonomous controller developed was designed to support the user in dynamic objects-crowded conditions. In a second phase, it has been assessed whether a semi-autonomous system associated with a machine learning myo-controller could improve the performance compared to the same machine learning controller alone. To assess this system, eight able-bodied and two amputee participants performed a newly developed test featuring a sequence of re-localisation tasks in a scene with multiple objects. The two amputee participants completed a standard rehabilitation test as well. The results revealed that the semi-autonomous system increased the time performance and reduced the physical effort for the total duration of the trial, and more specifically, in the preshaping phase of the task. The semi-autonomous system also reduced the need to control the prosthetic wrist manually. Eventually, the last part of this dissertation focuses on the interactions between the autonomous controller and the user. It investigates the impact, through the addition of artificial error on the autonomous system output, of different shared control modalities which define the application, according to the user’s commands, of the decisions of the autonomous controller on the prosthesis. Ten able-bodied participants performed a dual-task combining a reach-and-grasp task and an auditory reaction task. Time performance, physical and cognitive workload were recorded. This test implemented different control-sharing modalities at different levels of error. The results revealed that the shared control modalities significantly impact the task performance and the physical effort required to complete the task. The effect of the level of added errors on the three different outcomes varies between the control-sharing modalities. These results, therefore, provide valuable information to design and compare semi-autonomous upper limb prosthesis systems. In conclusion, by demonstrating the benefit of semi-autonomous systems and the investigation of their application conditions, this thesis advances the development of a new generation of prosthesis controllers that automatize parts of the actuation of the prosthesis. This research enlarges the current control bottleneck, which prevents prosthesis users from taking full advantage of their highly developed device. Therefore, it can contribute to increasing the support and the autonomy that upper limb prostheses can provide to their users in daily life.

Previous research on elderly people has suggested that footwear may improve neuromuscular control of motion. If footwear does in fact improve neuromuscular control, then such an influence might already be present in young, healthy adults. A feature that is often used to assess neuromuscular control of motion is the level of gait asymmetry. The objectives of the study were (a) to develop a comprehensive asymmetry index (CAI) that is capable of detecting gait asymmetry changes caused by external boundary conditions such as footwear, and (b) to use the CAI to investigate whether footwear influences gait asymmetry during running in a healthy, young cohort. Kinematic and kinetic data were collected for both legs of 15 subjects performing five barefoot and five shod over-ground running trials. Thirty continuous gait variables including ground reaction forces and variables of the hip, knee, and ankle joints were computed for each leg. For each individual, the differences between the variables for the right and left leg were calculated. Using this data, a principal component analysis was conducted to obtain the CAI. This study had two main outcomes. First, a sensitivity analysis suggested that the CAI had an improved sensitivity for detecting changes in gait asymmetry caused by external boundary conditions. The CAI may, therefore, have important clinical applications such as monitoring the progress of neuromuscular diseases (e.g. stroke or cerebral palsy). Second, the mean CAI for shod running (131.2 ± 48.5; mean ± standard deviation) was significantly lower (p = 0.041) than the CAI for barefoot running (155.7 ± 39.5). This finding suggests that in healthy, young adults gait asymmetry is reduced when running in shoes compared to running barefoot, which may be a result of improved neuromuscular control caused by changes in the afferent sensory feedback.

Background: Children with cerebral palsy (CP) often present with substantial motor impairments that affect both gait and postural control. A comprehensive multidimensional assessment of abnormal gait patterns is essential to establish a theoretical foundation for individualized rehabilitation strategies. Methods: Fifteen children with spastic hemiplegia (SH), 13 children with spastic diplegia (SD), and 30 typically developing (TD) children participated in an 8-minute upright walking task. Temporal gait parameters and kinematic angle parameters were recorded. Gait symmetry was quantified using the phase symmetry index (ID ps ), F-step size symmetry index (ID sp ), and asymmetry index (ASI). Gait variability was evaluated through sample entropy (SampEn), gait variability index (GVI), and gait deviation index (GDI). In addition, continuous relative phase (CRP) analysis was used to quantify the inter-joint coordination of ankle-knee, ankle-hip, and knee-hip joint pairs. Statistical analysis was performed using 1-way analysis of variance (ANOVA). Results: The TD group demonstrated significantly superior gait symmetry compared with both the SD and SH groups. The bilateral GDI index in TD group was significantly greater than that in SD and SH groups. Significant differences in SampEn for temporal parameters and kinematic angle were primarily observed between TD group and SD group. Except the SampEn for the left foot roll angle and ankle joint, all other statistically significant SampEn for metrics showed higher values in the children with cerebral palsy (CP) than in TD group; the mean absolute relative phase (MARP) value of the left ankle-knee joint pair in SD group showed a significant decrease during the initial swing phase (ISw). Conclusions: The results indicated that children with CP exhibited more complex temporal structures and kinematic variations in gait cycle. The foot-ankle showed a more rigid gait pattern, with discrepancies in ankle-knee coordination, suggesting the critical role of the foot-ankle in walking. These findings can assist clinicians in assessing children’s motor control capabilities and compensatory strategies, providing quantitative evidence for establishing individualized training objectives.

Objective and accurate evaluation of patients who underwent lower limb operation is important in determining a proper rehabilitation process according to the patient's recovery status. Gait symmetry analysis is a common protocol that is used to evaluate lower limb function; however, most studies have focused only on the terminal symmetry of lower limb during gait motion and were unable to provide information about detailed motions of the whole leg. To more accurately analyze mutual symmetry of the left and right leg during gait motion, measurement of motions of the whole left and right leg including the pelvis, hip, knee, and ankle is required. Eight patients (mean [standard deviation]: age = 22.87 [6.05] years; height = 167.81 [5.86] cm; weight = 629.52 [133.63] Newtons) who underwent limbsalvage surgery and eight normal volunteers (age = 28.87 [3.79] years; height = 167 [8.36] cm; weight = 657.46 [157.02] Newtons) participated in this study. Using motion capture cameras arranged around each subject, real-time gait motion of each participant was recorded and moving trajectories of 12 submotion elements were extracted. Mutual symmetry of the motion between the left and right leg was then calculated using a Pearson correlation method, while a nonparametric Mann-Whitney test was performed for group comparison. Experimental results showed that the moving trajectories of the left and right leg were similar in the normal group (r = 0.8114[0.22]) but were critically different in the patient group (r = 0.624286[0.15]). In addition, there was statistically significant difference (p = 0.0162) in gait symmetry between the normal group and the patient group (95% confidence level). We conclude that the proposed protocol can provide a useful evaluation tool for patient recovery condition and that it could be helpful in establishing an effective postoperative treatment protocol for lower limb patients.

Purpose: Upper limb prostheses are part of a rapidly changing market place. Despite development in device design, surveys report low levels of uptake and dissatisfaction with current prosthetic design. In this study, we present the results of a survey conducted with people with upper limb difference in Australia on their use of current prostheses and preferences in a prosthetic in order to inform future prosthetic hand design.Methods: An online survey was conducted on upper limb amputees, with 27 respondents that completed the survey. The survey was a mixture of open-ended questions, ranking design features and quantitative questions on problems experienced and desired attributes of future prosthesis designs.Results: Common key issues and concerns were isolated in the survey related to the weight, manipulation and dexterity, aesthetics, sensory feedback and financial cost; each of which could be addressed by additive manufacturing and soft robotics techniques.Conclusions: The adaptability of additive manufacturing and soft robotics to the highlighted concerns of participants shows that further research into these techniques is a feasible method to improve patient satisfaction and acceptance in prosthetic hands.Implications for rehabilitationEven with recent developments and advances in prosthetic design, the needs and desires of prosthetic users are not being met with current products.The desires and needs of those with upper limb difference are diverse.Using additive manufacturing to produce prosthetics allows for mass customization of prosthetics to meet these diverse needs while reducing costs.A soft robotic approach to prosthetics can help meet the desires of reducing weight and costs, while maintaining functionality.

It is well documented that there is a strong relationship between gait asymmetry and the freezing of gait (FOG) in Parkinson’s Disease. The purpose of this pilot study was to find a “virtual reality (VR)- based” gait manipulation strategy to improve gait symmetry by equalizing step length. Fifteen male PD patients (mean age of 67.6 years) with FOG were assessed on a GAITRite® walkway. Natural gait was compared with walking conditions during “VR-based” gait modulation tasks that aimed at equalizing gait symmetry using visual or proprioceptive signals. Compared to natural gait, VR manipulation tasks significantly increased step width and swing time variability for both body sides. Within the VR conditions, only the task with “proprioceptive-visual dissociation” by artificial backward shifting of the foot improved spatial asymmetry significantly with comparable step lengths of both sides. Specific, hypothesis-driven VR tasks represent an efficient tool to manipulate gait features as gait symmetry in PD potentially preventing FOG. This pilot study offers promising “VR-based” approaches for rehabilitative training strategies to achieve gait symmetry and prevent FOG.

Biomechanical gait impairments, such as reduced paretic propulsion, are common post-stroke. Studies have used biofeedback to increase paretic propulsion and reduce propulsion asymmetry, but it is unclear if these changes impact overall gait asymmetry. There is an implicit assumption that reducing propulsion asymmetry will improve overall gait symmetry, as paretic propulsion has been related to numerous biomechanical impairments. However, no work has investigated the impact of reducing propulsion asymmetry on overall gait asymmetry. We aimed to understand how within-session changes in propulsion asymmetry affect overall gait asymmetry, operationalized as the combined gait asymmetry metric (CGAM). We hypothesized that decreasing propulsion asymmetry would reduce CGAM. Methods. Participants completed twenty minutes of biofeedback training designed to increase paretic propulsion. We calculated the change in propulsion asymmetry magnitude and the change in CGAM (ΔCGAM) during biofeedback relative to baseline. Then, we fit a robust linear mixed-effects model with ΔCGAM as the outcome and a fixed effect for . Results. We found a positive association between and ΔCGAM (β = 2.6, p = 0.002). The average was - 0.09, suggesting that, on average, we would expect a CGAM change of 0.2, which is 0.5% of the average baseline CGAM value. Conclusions. Reducing propulsive asymmetry using biofeedback is unlikely to produce substantial reductions in overall gait asymmetry, suggesting that biofeedback-based approaches to reduce propulsion asymmetry may need to be combined with other interventions to improve overall gait asymmetry. Clinical Trial Registration. NCT04411303.

Introduction Upper-limb prostheses have undergone substantial technological improvements in the last two decades, but user complaints and abandonment rates have hardly changed. This may follow from the use of laboratory-based tests when assessing new technology instead of measuring prosthesis use in at-home situations. Serious games might be used to assess prosthesis use at home. Objectives The aim of this study was to assess the feasibility, validity, and reliability of using serious games to measure myocontrol in at-home situations. Study Design The design of this study is a cohort study with repeated measurements. Methods All 10 participants (five males; seven transradial and three transhumeral defects) used pattern recognition (PR) to control their prosthesis. Two serious games were included in the PR software: Simon Says and In-The-Zone. Participants were instructed to use their prosthesis as they normally would for 2 weeks with the additional instruction to play at least 18 serious games (±90 minutes in total). Outcome measures for aspects of prosthesis use were wear time, months of prosthesis use, and user experiences, and serious games outcomes were success rate and completion time. Results For feasibility, all but one participant completed the minimum of 18 games, and user experiences were mostly positive. For validity, no relationships were found between the aspects of prosthesis use and performance in the serious games. For reliability, test-retest reliability for success rate was high (intraclass correlation [ICC], 0.79), but low for completion time (ICC, 0.18) in both games. Conclusions Feasibility and reliability of using serious games as an assessment instrument for prosthesis control in at-home situations appeared to be good; however, validity could not be established. The serious games should be improved to increase validity. Furthermore, more outcome measures that reveal aspects of prosthesis use should be considered. Clinical Relevance Statement Assessing myocontrol in at-home situations by using serious games is feasible and reliable, but validity needs further attention.

Following stroke, people commonly demonstrate locomotor impairments including reduced walking speed and spatiotemporal asymmetry. Rehabilitation programs have been effective in increasing gait speed, but spatiotemporal asymmetry has been more resistant to change. The inability to modify gait patterns for improved symmetry may be related, in part, to impairments in lower extremity sensation. Assessment of lower extremity sensory impairments in people post stroke, including cutaneous and proprioceptive sensation, has been insufficiently studied. Conventional rehabilitation programs, including body weight-supported walking or robotic assistance, that modify sensory feedback intended to alter lower extremity movement patterns have shown limited success in improving gait symmetry. Rehabilitation programs that amplify specific gait asymmetries have demonstrated the potential to ultimately produce more symmetric gait, presumably by allowing individuals post stroke to more readily perceive their gait asymmetry. The effectiveness of such error augmentation paradigms, however, may be influenced by lower extremity sensation and the ability of the central nervous system to be aware of altered lower extremity movement. The purpose of this review is to critically examine the literature on lower extremity sensory function and its influence on gait adaptation in people post stroke.