Reliability of spatiotemporal asymmetry during overground walking for individuals following chronic stroke

Can a passive unilateral hip exosuit diminish walking asymmetry? A randomized trial

BACKGROUND

Asymmetric walking gait impairs activities of daily living in neurological patient populations, increases their fall risk, and leads to comorbidities. Accessible, long-term rehabilitation methods are needed to help neurological patients restore symmetrical walking patterns. This study aimed to determine if a passive unilateral hip exosuit can modify an induced asymmetric walking gait pattern. We hypothesized that a passive hip exosuit would diminish initial- and post-split-belt treadmill walking after-effects in healthy young adults.

METHODS

We divided 15 healthy young adults evenly between three experimental groups that each completed a baseline trial, an adaptation period with different interventions for each group, and a post-adaptation trial. To isolate the contribution of the exosuit we compared a group adapting to the exosuit and split-belt treadmill (Exo-Sb) to groups adapting to exosuit-only (Exo-only) and split-belt only (Sb-only) conditions. The independent variables step length, stance time, and swing time symmetry were analyzed across five timepoints (baseline, early- and late adaptation, and early- and late post-adaptation) using a 3 × 5 mixed ANOVA.

RESULTS

We found significant interaction and time effects on step length, stance time and swing time symmetry. Sb-only produced increased step length asymmetry at early adaptation compared to baseline (p < 0.0001) and an after-effect with increased asymmetry at early post-adaptation compared to baseline (p < 0.0001). Exo-only increased step length asymmetry (in the opposite direction as Sb-only) at early adaptation compared to baseline (p = 0.0392) but did not influence the participants sufficiently to result in a post-effect. Exo-Sb produced similar changes in step length asymmetry in the same direction as Sb-only (p = 0.0014). However, in contrast to Sb-only there was no significant after-effect between early post-adaptation and baseline (p = 0.0885).

CONCLUSION

The passive exosuit successfully diminished asymmetrical step length after-effects induced by the split-belt treadmill in Exo-Sb. These results support the passive exosuit's ability to alter walking gait patterns.

Effectiveness of an 8-week overground walking with paretic lower limb loading on spatiotemporal gait parameters and motor function among chronic stroke survivors: a protocol for randomised controlled trial

BACKGROUND

Post-stroke gait deviations contribute to significant functional disability, impaired walking ability and poor quality of life. Prior studies suggest that gait training with paretic lower limb loading may improve gait parameters and walking ability in post-stroke. However, most gait training methods used in these studies are not readily available, and studies using cheaper methods are limited.

OBJECTIVE

The purpose of this study is to describe a protocol for a randomised controlled trial on the effectiveness of an 8-week overground walking with paretic lower limb loading on spatiotemporal gait parameters and motor function among chronic stroke survivors.

METHODS

This is a two-center, single-blind, two-arm parallel randomised controlled trial. Forty-eight stroke survivors with mild to moderate disability will be recruited from two tertiary facilities and randomly assigned into two intervention arms; overground walking with paretic lower limb loading or overground walking without paretic lower limb loading in a 1:1 ratio. All interventions will be administered thrice weekly for 8 weeks. Primary outcomes will be step length and gait speed whereas the secondary outcomes will include step length symmetry ratio, stride length, stride length symmetry ratio, stride width, cadence and motor function. All outcomes will be assessed at baseline, 4, 8 and 20 weeks after the start of intervention.

DISCUSSION

This will be the first randomised controlled trial to report the effects of overground walking with paretic lower limb loading on spatiotemporal gait parameters and motor function among chronic stroke survivors from low-resource setting.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05097391. Registered on 27 October 2021.

Relative and absolute reliability of gait variables obtained from gait analysis with trunk acceleration in community-dwelling individuals with chronic stroke: a pilot study

[Purpose] This pilot study aimed to investigate the relative and absolute reliability of variables obtained from an acceleration-based gait analysis conducted at comfortable and maximal gait speeds in individuals with chronic stroke. [Participants and Methods] This study included 25 community-dwelling individuals with chronic stroke. The participants wore triaxial accelerometers, while an observed walking trial was performed at comfortable and maximal speeds on two separate days 1 week apart. Relative reliability was evaluated using the intraclass correlation coefficient, and absolute reliability was evaluated using the Bland-Altman analysis, standard error of measurement, and minimal detectable change. [Results] The intraclass correlation coefficient of gait varied according to the acceleration-based gait analysis, ranging from 0.70 to 0.99. The Bland-Altman analysis revealed no systematic bias in both comfortable and maximal gait speed conditions. Most of the minimal detectable changes were smaller at maximal gait speed than at comfortable gait speed. [Conclusion] Acceleration-based gait analysis is a reliable method, particularly in maximal gait speed conditions. It may be used to assess the effect of rehabilitation interventions in individuals with chronic stroke.

Instantaneous effect of real-time avatar visual feedback on interlimb coordination during walking post-stroke

BACKGROUND

Gait asymmetry, which is common after stroke, is typically characterized using spatiotemporal parameters of gait that do not consider the aspect of movement coordination. In this manuscript, we examined whether an avatar-based feedback provided as a single-session intervention to improve gait symmetry also improved inter-limb coordination among people with stroke and we examined the relationship between changes in coordination and step length symmetry.

METHODS

Twelve stroke participants walked on a self-paced treadmill with and without a self-avatar that replicated their locomotor movements in real time. Continuous relative phase and angular coefficient of correspondence calculated using bilateral sagittal hip movements were used to quantify temporal and spatial interlimb coordination, respectively. Spatial gait symmetry, previously shown to improve with the avatar feedback, was quantified using step length ratio between both limbs, with the largest value as numerator.

FINDINGS

Participants who improved their spatial symmetry during avatar exposure also improved their temporal coordination, while spatial coordination remained unchanged. Overall, improvements in spatial symmetry correlated positively with improvements in temporal coordination. The non-paretic hip and paretic ankle angle excursion in the sagittal plane also significantly increased during avatar exposure.

INTERPRETATION

Improvements in gait symmetry may be explained by changes in interlimb coordination. Current data and existing literature further suggest that such improvements are largely driven by adaptations in non-paretic leg movements, notably at the hip. By providing real-time information on walking movements not affordable in other ways, avatar-based feedback shows great potential to improve gait symmetry and interlimb coordination post-stroke.

Biomechanical differences between self-paced and fixed-speed treadmill walking in persons after stroke

BACKGROUND

Using self-paced treadmills for gait analysis requires less space compared to overground gait labs while a more natural walking pattern could be preserved compared to fixed-speed treadmill walking. Although self-paced treadmills have been used in stroke related intervention studies, studies comparing self-paced to fixed-speed treadmill walking in this population are scarce.

METHODS

Twenty-five persons after stroke (10 males/15 females; 53 ± 12.05 years; 40.72 ± 42.94 months post stroke) walked on a treadmill in a virtual environment (GRAIL, Motek) in two conditions (self-paced and fixed-speed). After familiarization, all participants completed two trials (3 min) at comfortable walking velocity in randomized order. A paired-sample t-test or Wilcoxon Signed Rank test was used to calculate differences between both conditions for spatiotemporal parameters. Statistical Parametric mapping was conducted using the t-tests (SPM(t)), to statistically compare the kinematic and kinetic curves.

RESULTS

The self-selected walking velocity on the treadmill was higher in the self-paced condition compared to the fixed-speed condition (p < 0.001). However, most variability and symmetry measures were similar in both conditions. Only the standard deviation of the step length at the paretic side was significant higher (p = 0.007) and step length symmetry was significantly better (p = 0.032) in the self-paced condition. Detected kinematic and kinetic differences were small (< 3°, < 0.1 Nm/kg) and stride to stride variability was comparable in both conditions.

CONCLUSION

Based on the results of the current study, self-paced walking can be used as an equivalent to fixed-speed treadmill walking in persons after stroke. Accordingly, this justifies the use of this more functional mode in clinical gait assessment and rehabilitation trials.

The reliability of gait parameters captured via instrumented walkways: a systematic review and meta-analysis

INTRODUCTION

Electronic pressure-sensitive walkways are commonly available solutions to quantitatively assess gait parameters for clinical and research purposes. Many studies have evaluated their measurement properties in different conditions with variable findings. In order to be informed about the current evidence of their reliability for optimal clinical and scientific decision making, this systematic review provided a quantitative synthesis of the test-retest reliability and minimal detectable change of the captured gait parameters across different test conditions (single and cognitive dual-task conditions) and population groups.

EVIDENCE ACQUISITION

A literature search was conducted in PubMed, Embase, and Scopus until November 2021 to identify articles that examined the test-retest reliability properties of the gait parameters captured by pressure-sensitive walkways (gait speed, cadence, stride length and time, double support time, base of support) in adult healthy individuals or patients. The methodological quality was rated using the Consensus-Based Standards for the Selection of Health Measurement Instruments Checklist. Data were meta-analyzed on intraclass correlation coefficient to examine the test-retest relative reliability. Quantitative synthesis was performed for absolute reliability, examined by the weighted average of minimal detectable change values.

EVIDENCE SYNTHESIS

A total of 44 studies were included in this systematic review. The methodological quality was adequate in half of the included studies. The main finding was that pressure-sensitive walkways are reliable tools for objective assessment of spatial and temporal gait parameters both in single-and cognitive dual-task conditions. Despite few exceptions, the review identified intraclass correlation coefficient higher than 0.75 and minimal detectable change lower than 30%, demonstrating satisfactory relative and absolute reliability in all examined populations (healthy adults, elderly, patients with cognitive impairment, spinocerebellar ataxia type 14, Huntington's disease, multiple sclerosis, Parkinson's disease, rheumatoid arthritis, spinal cord injury, stroke or vestibular dysfunction).

CONCLUSIONS

Current evidence suggested that, despite different populations and testing protocols used in the included studies, the test-retest reliability of the examined gait parameters was acceptable under single and cognitive dual-task conditions. Further high-quality studies with powered sample sizes are needed to examine the reliability findings of the currently understudied and unexplored pathologies and test conditions.

Reliability of IMU-Based Gait Assessment in Clinical Stroke Rehabilitation

Background: Gait is often impaired in people after stroke, restricting personal independence and affecting quality of life. During stroke rehabilitation, walking capacity is conventionally assessed by measuring walking distance and speed. Gait features, such as asymmetry and variability, are not routinely determined, but may provide more specific insights into the patient’s walking capacity. Inertial measurement units offer a feasible and promising tool to determine these gait features. Objective: We examined the test–retest reliability of inertial measurement units-based gait features measured in a two-minute walking assessment in people after stroke and while in clinical rehabilitation. Method: Thirty-one people after stroke performed two assessments with a test–retest interval of 24 h. Each assessment consisted of a two-minute walking test on a 14-m walking path. Participants were equipped with three inertial measurement units, placed at both feet and at the low back. In total, 166 gait features were calculated for each assessment, consisting of spatio-temporal (56), frequency (26), complexity (63), and asymmetry (14) features. The reliability was determined using the intraclass correlation coefficient. Additionally, the minimal detectable change and the relative minimal detectable change were computed. Results: Overall, 107 gait features had good–excellent reliability, consisting of 50 spatio-temporal, 8 frequency, 36 complexity, and 13 symmetry features. The relative minimal detectable change of these features ranged between 0.5 and 1.5 standard deviations. Conclusion: Gait can reliably be assessed in people after stroke in clinical stroke rehabilitation using three inertial measurement units.

The gait profile score characterises walking performance impairments in young stroke survivors

BACKGROUND

The Gait Profile Score (GPS) provides a composite measure of the quality of joint movement during walking, but the relationship between this measure and metabolic cost, temporal (e.g. walking speed) and spatial (e.g. stride length) parameters in stroke survivors has not been reported.

RESEARCH QUESTION

The aims of this study were to compare the GPS (paretic, non-paretic, and overall score) of young stroke survivors to the healthy able-bodied control and determine the relationship between the GPS and metabolic cost, temporal (walking speed, stance time asymmetry) and spatial (stride length, stride width, step length asymmetry) parameters in young stroke survivors to understand whether the quality of walking affects walking performance in stroke survivors.

METHODS

Thirty-nine young stroke survivors aged between 18 and 65years and 15 healthy age-matched able-bodied controls were recruited from six hospital sites in Wales, UK. Joint range of motion at the pelvis, hip, knee and ankle, and temporal and spatial parameters were measured during walking on level ground at self-selected speed with calculation of the Gait Variable Score and then the GPS.

RESULTS

GPS for the paretic leg (9.40° (8.60-10.21) p < 0.001), non-paretic leg (11.42° (10.20-12.63) p < 0.001) and overall score (11.18° (10.26-12.09) p < 0.001)) for stroke survivors were significantly higher than the control (4.25° (3.40-5.10), 5.92° (5.11 (6.73)). All parameters with the exception of step length symmetry ratio correlated moderate to highly with the GPS for the paretic, non-paretic, and/or overall score (ρ = <-0.732 (p < 0.001)).

SIGNIFICANCE

The quality of joint movement during walking measured via the GPS is directly related to the speed and efficiency of walking, temporal (stance time symmetry) and spatial (stride length, stride width) parameters in young stroke survivors.

Longitudinal Changes in Temporospatial Gait Characteristics during the First Year Post-Stroke

Given the paucity of longitudinal data in gait recovery after stroke, we compared temporospatial gait characteristics of stroke patients during subacute (<2 months post-onset, T0) and at approximately 6 and 12 months post-onset (T1 and T2, respectively) and explored the relationship between gait characteristics at T0 and the changes in gait speed from T0 to T1. Forty-six participants were assessed at T0 and a subsample of twenty-four participants were assessed at T2. Outcome measures included Fugl-Meyer lower-extremity motor score, 14 temporospatial gait parameters, and symmetry indices of 5 step parameters. Except for step width, all temporospatial parameters improved from T0 to T1 (p ≤ 0.0001). Additionally, significant improvements in symmetry were found for the initial double-support time and single-support time (p ≤ 0.0001). As a group, no significant differences were found between T1 and T2 in any of the temporospatial measures. However, the individual analysis revealed that 42% (10/24) of the subsample showed a significant increase in gait speed (Welch’s t-test, p ≤ 0.002). Yet, only 5/24 (21%) of the participants improved speed from T1 to T2 according to speed-based minimum detectable change criteria. The increase in gait speed from T0 to T1 was negatively correlated with gait speed and stride length and positively correlated with the symmetry indices of stance and single-support times at T0 (p ≤ 0.002). Temporospatial gait parameters and stance time symmetry improved over the first 6 months after stroke with an apparent plateau thereafter. A greater increase in gait speed during the first 6 months post-stroke is associated with initially slower walking, shorter stride length, and more pronounced asymmetry in stance and single-support times. The improvement in lower-extremity motor function and bilateral improvements in step parameters collectively suggest that gait changes over the first 6 months after stroke are likely due to a combination of neurological recovery, compensatory strategies, and physical therapy received during that time.

Design and Initial Validation of a Multiple Degree-of-Freedom Joint for an Ankle-Foot Orthosis

This paper presents the novel design of a Multi-Degree-Of-Freedom joint (M-DOF) for an Ankle-Foot Orthosis (AFO) that aims to improve upon the commercially available Double Action Joint (DAJ). The M-DOF is designed to maintain the functionality of the DAJ, while increasing dorsiflexion stiffness and introducing inversion/eversion. This increase in range of motion is designed to produce greater engagement from lower limb muscles during gait. The M-DOF was experimentally validated with one able-bodied and one stroke subject. Across walking speeds, the M-DOF AFO minimally affected the able-bodied subject's joint kinematics. The stroke subject's ankle dorsiflexion/plantarflexion and knee flexion were not heavily altered when wearing the M-DOF AFO, compared to the DAJ AFO. The new DOF allowed by the M-DOF AFO increased the inversion/eversion of the ankle by ~3°, without introducing any new compensations compared to their gait with the DAJ AFO.

Dynamic balance recovery in chronic acquired brain injury participants following a perturbation training

Acquired brain injury (ABI) is defined as a damage to the brain that occurs after birth. Subjects post-ABI frequently suffer from dynamic balance impairments that persist years after the injury. This study aimed to investigate the effect of a perturbation method using mechatronic shoes that introduce unexpected balance perturbations on the recovery of dynamic balance and gait velocity in chronic ABI participants. In an intervention trial, 35 chronic ABI participants (stroke and traumatic brain injury) participated in 22 sessions of perturbation training, twice a week for 3 months. Dynamic balance was assessed pre- and post-training using Community Balance and Mobility Scale (CB&M). Gait velocity was also assessed in the stroke participants using the 10 Meter Walking Test (10MWT). Dynamic balance improved significantly post-training (P = 0.001). This improvement was greater than the improvement that was observed in a sub-group that was tested twice before training (P = 0.04). Sixteen participants (45.7%) out of 35 met or exceeded minimal detectable change (MDC) of the CB&M Scale. Self-paced velocity also improved significantly (P = 0.02) but only two participants (9.5%) out of 21 exceeded the MDC of 10MWT post-stroke. Our results suggest that unexpected balance perturbation training using mechatronic shoes leads to an improvement in dynamic balance and gait velocity in chronic ABI participants. The advantage of perturbation training using mechatronic shoes with respect to conventional balance training should be further examined.

Efficacy of a Novel Exoskeletal Robot for Locomotor Rehabilitation in Stroke Patients: A Multi-center, Non-inferiority, Randomized Controlled Trial

Objective: To investigate the efficacy and safety of a novel lower-limb exoskeletal robot, BEAR-H1 (Shenzhen Milebot Robot Technology), in the locomotor function of subacute stroke patients. Methods: The present study was approved by the ethical committee of the First Affiliated Hospital of Nanjing Medical University (No. 2019-MD-43), and registration was recorded on the Chinese Clinical Trial Registry with a unique identifier: ChiCTR2100044475. A total of 130 patients within 6 months of stroke were randomly divided into two groups: the robot group and the control group. The control group received routine training for walking, while in the robot group, BEAR-H1 lower-limb exoskeletal robot was used for locomotor training. Both groups received two sessions daily, 5 days a week for 4 weeks consecutively. Each session lasted 30 min. Before treatment, after treatment for 2 weeks, and 4 weeks, the patients were assessed based on the 6-minute walking test (6MWT), functional ambulation scale (FAC), Fugl-Meyer assessment lower-limb subscale (FMA-LE), and Vicon gait analysis. Results: After a 4-week intervention, the results of 6MWT, FMA-LE, FAC, cadence, and gait cycle in the two groups significantly improved (P < 0.05), but there was no significant difference between the two groups (P > 0.05). The ratio of stance phase to that of swing phase, swing phase symmetry ratio (SPSR), and step length symmetry ratio (SLSR) was not significantly improved after 4 weeks of training in both the groups. Further analyses revealed that the robot group exhibited potential benefits, as the point estimates of 6MWT and Δ6MWT (post-pre) at 4 weeks were higher than those in the control group. Additionally, within-group comparison showed that patients in the robot group had a significant improvement in 6MWT earlier than their counterparts in the control group. Conclusions: The rehabilitation robot in this study could improve the locomotor function of stroke patients; however, its effect was no better than conventional locomotor training.

Functional capacity and walking speed reserve in individuals with chronic stroke: A cross-sectional study

INTRODUCTION

Individuals with stroke experience residual walking disabilities, as the inability to increase walking speed (walking speed reserve - WSR), and frequently present decreasing in functional capacity. The relation between functional capacity and walking ability may contribute to more specific functional management of stroke.

OBJECTIVE

To investigate the association between WSR and functional capacity in individuals with chronic stroke and compare functional capacity between individuals who can increase walking speed or not.

METHODS

Cross-sectional study, where functional capacity was assessed with the Duke Activity Status Index (DASI), in metabolic equivalent (METS). WSR was assessed through the difference between fast and self-selected speed (in m/s). The individuals were assigned into two groups: able (WSR ≥ 0.2 m/s) and unable (WSR<0.2 m/s) to increase speed. Pearson's correlation and t test were used for analysis.

RESULTS

Fifty-five individuals (functional capacity 23 ± 13 METS and WSR 0.3 ± 0.2 m/s) were included. The association between functional capacity and WSR was positive and statistically significant, with moderate magnitude (r = 0.56) (p < .001). Individuals who were unable to increase their walking speed have less functional capacity (17.5 versus 31.3) (p = .003).

CONCLUSION

Functional capacity has a positive association with WSR in individuals with chronic stroke. The individuals who are unable to increase walking speed present lower functional capacity.

Targeted verbal cues can immediately alter gait following stroke

Background: Physical therapists use verbal cueing extensively during gait rehabilitation. Nevertheless, little is known about the ability of individuals post-stroke to make immediate changes to targeted spatiotemporal gait parameters from verbal commands. Additionally, adequate muscle strength may be necessary to promote positive alterations in gait.Objectives: To determine the influence of targeted verbal cues on spatiotemporal gait parameters for individuals with chronic stroke. Further, we assessed the potential of a relationship between cue-induced gait modifications and paretic lower limb strength.Methods: Using a within-subjects design, twenty-seven adults with chronic stroke walked over a pressure mat with verbal cues to walk at (1) comfortable and (2) fast speeds, with increased (3) arm swing, (4) foot height, (5) step length, (6) push off, and (7) cadence. We also assessed lower extremity strength using a hand-held dynamometer. We measured gait speed, step length, stance time, and cadence for comparisons between conditions and performed correlational analyses to assess the influence of strength on gait alterations.Results: Specific cues elicited increased walking speed, cadence, step lengths and paretic limb stance time. Only greater paretic hip and knee flexion strength was related to the ability to increase cadence when cued to do so (r > 0.41).Conclusion: With targeted verbal cueing, clinicians can improve step length, gait speed, stance time and cadence for individuals with chronic stroke. Lower extremity strength does not appear to be related to the ability to alter gait with verbal cueing in individuals with chronic stroke.

Ankle Power Generation Has a Greater Influence on Walking Speed Reserve Than Balance Following Traumatic Brain Injury

OBJECTIVE

Reduced walking speed is common following traumatic brain injury (TBI). Walking speed reserve (WSR) refers to the ability to increase walking speed on demand and is calculated as the difference between self-selected and fast walking speeds. Walking speed reserve is important for adaptive functional mobility in the community. Predictors of WSR following TBI are yet to be determined. The aim of the study was to identify whether static balance or ankle power generation (APG) was a stronger predictor of WSR following TBI.

SETTING

A major metropolitan rehabilitation hospital.

PARTICIPANTS

A total of 92 individuals receiving inpatient physiotherapy for mobility limitations following TBI were recruited.

DESIGN

A cross-sectional study.

METHODS

Walking speed (self-selected and fast), APG, and a summed single-leg stance scores were measured. The ability to increase walking speed on demand by 0.20 m/s or more defined WSR. Correlations, logistic regression, and receiver operating characteristic (ROC) curve analyses were performed to investigate independent relationships between WSR, APG, and static balance.

RESULTS

Fifty participants (54.3%) had a WSR of 0.20 m/s or more. The strongest predictor of WSR was APG (odds ratio [OR] = 3.34; 95% CI, 1.50-7.43) when compared with static balance (OR = 1.03; 95% CI, 1.01-1.06). The ROC curve demonstrated that APG could accurately discriminate between individuals with a WSR from those without (AUC [area under the ROC curve] = 0.79; 95% CI, 0.70-0.88). The APG cutoff score identified on the curve that maximized combined sensitivity (92.0%) and specificity (54.8%) was 0.75 W/kg.

CONCLUSION

Following TBI, APG was a stronger predictor of WSR than static balance. Clinicians should consider interventions that preferentially target APG in order to increase WSR for community mobility.

Cerebellar Transcranial Direct Current Stimulation for Motor Learning in People with Chronic Stroke: A Pilot Randomized Controlled Trial

Cerebellar transcranial direct current stimulation (ctDCS) is a non-invasive brain stimulation technique that alters neural plasticity through weak, continuous, direct currents delivered to the cerebellum. This study aimed to evaluate the feasibility of conducting a randomized controlled trial (RCT) delivering three consecutive days of ctDCS during split-belt treadmill training (SBTT) in people with chronic stroke. Using a double-blinded, parallel-group RCT design, eligible participants were randomly allocated to receive either active anodal ctDCS or sham ctDCS combined with SBTT on three consecutive days. Outcomes were assessed at one-week follow-up, using step length symmetry as a measure of motor learning and comfortable over-ground walking speed as a measure of walking capacity. The feasibility of the RCT protocol was evaluated based on recruitment, retention, protocol deviations and data completeness. The feasibility of the intervention was assessed based on safety, adherence and intervention fidelity. Of the 26 potential participants identified over four months, only four were enrolled in the study (active anodal ctDCS n = 1, sham ctDCS n = 3). Both the inclusion criteria and the fidelity of the SBTT relied upon the accurate estimation of step length asymmetry. The method used to determine the side of the step length asymmetry was unreliable and led to deviations in the protocol. The ctDCS intervention was well adhered to, safe, and delivered as per the planned protocol. Motor learning outcomes for individual participants revealed that treadmill step length symmetry remained unchanged for three participants but improved for one participant (sham ctDCS). Comfortable over-ground walking speed improved for two participants (sham ctDCS). The feasibility of the planned protocol and intervention was limited by intra-individual variability in the magnitude and side of the step length asymmetry. This limited the sample and compromised the fidelity of the SBTT intervention. To feasibly conduct a full RCT investigating the effect of ctDCS on locomotor adaptation, a reliable method of identifying and defining step length asymmetry in people with stroke is required. Future ctDCS research should either optimize the methods for SBTT delivery or utilize an alternative motor adaptation task.

Walking test procedures influence speed measurements in individuals with chronic stroke

BACKGROUND

Walking speed measurements are clinically important, but varying test procedures may influence measurements and impair clinical utility. This study assessed the concurrent validity of walking speed in individuals with chronic stroke measured during the 10-m walk test with variations in 1) the presence of an electronic mat, 2) the speed measurement device, and 3) the measurement distance relative to the total test distance.

METHODS

Twenty-five individuals with chronic stroke performed walking tests at comfortable and maximal walking speeds under three conditions: 1) 10-m walk test (without electronic mat) measured by stopwatch, 2) 10-m walk test (partially over an electronic mat) measured by software, and 3) 10-m walk test (partially over an electronic mat) measured by stopwatch. Analyses of systematic bias, proportional bias, and absolute agreement were performed to determine concurrent validity between conditions.

FINDINGS

Walking speeds were not different between measurements (P ≥ 0.11), except maximal walking speed was faster when speed was measured with software vs. stopwatch (P = 0.002). Absolute agreement between measurements was excellent (ICC ≥ 0.97, P < 0.001). There was proportional bias between software vs. stopwatch (R² ≥ 0.19, P ≤ 0.03) and between tests with vs. without the electronic mat (R² = 0.27, P = 0.008). Comparisons between conditions revealed that walking speed and concurrent validity may be influenced by walking test distance, presence of an electronic mat, speed measurement device, and relative measurement distance.

INTERPRETATION

Walking test procedures influence walking speed and concurrent validity between measurements. Waking test procedures should be as similar as possible with normative data or between repeated measurements to optimize validity.

Treadmill-Based Locomotor Training With Robotic Pelvic Assist and Visual Feedback: A Feasibility Study

BACKGROUND AND PURPOSE

Gait asymmetries are common after stroke, and often persist despite conventional rehabilitation. Robots provide training at a greater practice frequency than conventional approaches. However, prior studies of have found the transfer of learned skills outside of the device to be inadequate. The tethered pelvic assist device (TPAD) promotes weight shifting, yet allows users to independently navigate spatiotemporal aspects of gait. The purpose of this study was to evaluate feasibility and preliminary efficacy of a 5-day intervention combining TPAD training with visual feedback and task-specific overground training to promote improved force and stance symmetry in individuals after stroke.

METHODS

After baseline assessments, 11 participants chronically after stroke received 1 hour of practice for 5 consecutive days. Training sessions included visual feedback during TPAD treadmill training followed by overground gait training. Safety, perceived exertion, and adherence were recorded as measures of feasibility. Load and stance symmetry were reassessed after the intervention (posttraining) and again 1 week later.

RESULTS

No adverse events were reported. Mean (SD) perceived exertion (3.61 (0.23)) was low and did not significantly change throughout the intervention. Overall adherence was 96.4%. Load asymmetry was not significantly reduced on the treadmill from baseline to posttraining (P = 0.075). Overground stance symmetry significantly improved on posttraining (F = 8.498, P = 0.002), but was not sustained at follow-up. (See the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A311, which summarizes the study background, methods, and results.) DISCUSSION AND CONCLUSIONS:: Results demonstrate this combined interventional approach was feasible and improved stance symmetry overground, yet further work should consider increasing training intensity and/or duration to induce gains lasting through follow-up.

Minimal Detectable Change for Gait Speed Depends on Baseline Speed in Individuals With Chronic Stroke

BACKGROUND AND PURPOSE

Given the heterogeneity of mobility outcomes after stroke, the purpose of this study was to examine how the minimal detectable change (MDC) for gait speed varies based on an individual's baseline walking speed.

METHODS

Seventy-six participants with chronic stroke and able to walk without therapist assistance participated in 2 visits to record overground self-selected comfortable gait speed (CGS) and fast gait speed (FGS). Based on the CGS at visit 1, participants were assigned to 1 of 3 speed groups: low (<0.4 m/s; n = 32), moderate (0.4-0.8 m/s; n = 29), and high functioning group (>0.8 m/s; n = 15). Participants were then reclassified using updated gait speed cutoffs of 0.49 and 0.93 m/s. For each group, we determined test-retest reliability between visits, and the MDC for CGS and FGS.

RESULTS

Gait speed significantly increased from visit 1 to visit 2 for each group (P < 0.001). The reliability for CGS declined with increasing gait speed, and MDC95 values increased with increasing gait speed (low: 0.10 m/s; moderate: 0.15 m/s; and high: 0.18 m/s). Similar findings were observed for FGS, and when participants were recoded using alternative thresholds.

DISCUSSION AND CONCLUSIONS

Slower walkers demonstrated greater consistency in walking speed from day to day, which contributed to a smaller MDC95 than faster walkers. These data will help researchers and clinicians adjust their expectations and goals when working with individuals with chronic stroke. Expectations for changing gait speed should be based on baseline gait speed, and will allow for more appropriate assessments of intervention outcomes. AVAILABLE: for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A253).

Use of real-time visual feedback during overground walking training on gait symmetry and velocity in patients with post-stroke hemiparesis: randomized controlled, single-blind study

This study aimed to determine the efficacy of using real-time visual feedback during overground walking training to improve walking function in patients with post-stroke hemiparesis. Twenty-four patients with post-stroke hemiparesis who were able to walk independently under less impact of synergy pattern on the affected lower limbs (Brunnstrom stage IV or V) were randomly assigned to either the experimental group or the control group. All subjects performed overground walking for 30 min, three times a week for 6 weeks, with real-time visual feedback (weight load to the affected lower limb) provided during training for subjects in the experimental group. Outcome measures comprised the timed up-and-go test and gait parameters (step length, stride length, single and double support times, step and stride length ratios, and single support time ratio). In between-group comparison, the changes between pre-test and post-test scores in all parameters were significantly greater in the experimental group than in the control group (P < 0.05), except for double support time and step length ratio. Furthermore, post-test values of all parameters were significantly more improved in the experimental group than in the control group (P < 0.05). Our findings suggest that real-time visual feedback may be an advantageous therapeutic adjunct to reinforce the effects of overground walking training in patients with post-stroke hemiparesis.

Genetic polymorphisms for BDNF, COMT, and APOE do not affect gait or ankle motor control in chronic stroke: A preliminary cross-sectional study

Background: Motor deficits after stroke are a primary cause of long-term disability. The extent of functional recovery may be influenced by genetic polymorphisms. Objectives: Determine the effect of genetic polymorphisms for brain-derived neurotrophic factor (BDNF), catechol-O-methyltransferase (COMT), and apolipoprotein E (APOE) on walking speed, walking symmetry, and ankle motor control in individuals with chronic stroke. Methods: 38 participants with chronic stroke were compared based upon genetic polymorphisms for BDNF (presence [MET group] or absence [VAL group] of a Met allele), COMT (presence [MET group] or absence [VAL group] of a Met allele), and APOE (presence [ε4+ group] of absence [ε4- group] of ε4 allele). Comfortable and maximal walking speed were measured with the 10-m walk test. Gait spatiotemporal symmetry was measured with the GAITRite electronic mat; symmetry ratios were calculated for step length, step time, swing time, and stance time. Ankle motor control was measured as the accuracy of performing an ankle tracking task. Results: No significant differences were detected (p ≥ 0.11) between the BDNF, COMT, or APOE groups for any variables. Conclusions: In these preliminary findings, genetic polymorphisms for BDNF, COMT, and APOE do not appear to affect walking speed, walking symmetry, or ankle motor performance in chronic stroke.

Reliability, measurement error and minimum detectable change in mobility measures: a cohort study of community-dwelling adults aged 50 years and over in Ireland

OBJECTIVE

To estimate the effects of repeat assessments, rater and time of day on mobility measures and to estimate their variation between and within participants in a population-based sample of Irish adults aged ≥50 years.

DESIGN

Test-retest study in a population representative sample.

SETTING

Academic health assessment centre of The Irish Longitudinal Study on Ageing (TILDA).

PARTICIPANTS

128 community-dwelling adults from the Survey for Health, Ageing and Retirement in Europe (SHARE) Ireland study who agreed to take part in the SHARE-Ireland/TILDA collaboration.

INTERVENTIONS

Not applicable.

OUTCOME MEASURES

Participants performed timed up-and-go (TUG), repeated chair stands (RCS) and walking speed tests administered by one of two raters. Repeat assessments were conducted 1-4 months later. Participants were randomised with respect to a change in time (morning, afternoon) and whether the rater was changed between assessments. Within and between-participant variance for each measure was estimated using mixed-effects models. Intraclass correlation (ICC), SE of measurement and minimum detectable change (MDC) were reported.

RESULTS

Average performance did not vary between baseline and repeat assessments in any test, except RCS. The rater significantly affected performance on all tests except one, but time of day did not. Reliability varied from ICC=0.66 (RCS) to ICC=0.88 (usual gait speed). MDC was 2.08 s for TUG, 4.52 s for RCS and ranged from 19.49 to 34.73 cm/s for walking speed tests. There was no evidence for lower reliability of gait parameters with increasing time between assessments.

CONCLUSIONS

Reliability varied for each test when measurements are obtained over 1-4 months with most variation due to rater effects. Usual and motor dual task gait speed demonstrated highest reliability.

Effects of Load Addition During Gait Training on Weight-Bearing and Temporal Asymmetry After Stroke: A Randomized Clinical Trial

OBJECTIVE

The aim of the study was to evaluate the effects of adding load to restrain the nonparetic lower limb during gait training on weight-bearing and temporal asymmetry after stroke.

DESIGN

Thirty-eight subjects were randomized into treadmill training with load (5% of body weight) on the nonparetic limb (experimental group) and treadmill training without load (control group). Interventions lasted 30 mins/d for 2 wks (9 sessions). Both groups performed home-based exercises and were instructed to increase the use of paretic limb in daily life situations. Ground reaction force was obtained by a force plate during standing position (static) and gait (dynamic). Temporal gait parameters were assessed by a motion system analysis. Outcome measures were evaluated at baseline, posttraining, and after a 40-day follow-up.

RESULTS

The experimental group increased static ground reaction force of the paretic limb at posttraining (P = 0.037) and the control group increased dynamic ground reaction force of the paretic limb at posttraining (P = 0.021), both with maintenance at follow-up. Neither group showed a change in the swing time symmetry ratio after training (P = 0.190).

CONCLUSIONS

Treadmill training associated with behavioral strategies/home-based exercises seemed to be useful to minimize weight-bearing asymmetry, but not to improve temporal gait asymmetry. Load addition did not show additional benefits.

Return to Employment After Stroke in Young Adults: How Important Is the Speed and Energy Cost of Walking?

Supplemental Digital Content is available in the text.

A quarter of individuals who experience a stroke are under the age of 65 years (defined as young adults), and up to 44% will be unable to return to work poststroke, predominantly because of walking difficulties. No research study has comprehensively analyzed walking performance in young adult’s poststroke. The primary aim of this study is to investigate how a stroke in young adults affects walking performance (eg, walking speed and metabolic cost) compared with healthy age-matched controls. The secondary aim is to determine the predictive ability of walking performance parameters for return to employment poststroke.

Test-retest reliability and minimal detectable change for measures of balance and gait in adults with cerebral palsy

BACKGROUND

Walking and balance often begin to deteriorate in ambulant adults with cerebral palsy (CP) in early adulthood. The decline in walking and balance imposes a more sedentary lifestyle, increases falls risk, negatively affects health, participation, and quality of life, and ultimately results in increased disability. Available research is not sufficient to guide interventions to improve walking and balance in this population. To advance research in this area, there is a need for measures of gait and balance with proven psychometrics for adults with CP.

RESEARCH QUESTION

The goal of this study was to determine test-retest reliability and minimal detectable change (MDC) values and to assess score distribution for the Balance Evaluation Systems Test (BESTest) and the Four Square Step Test (FSST) as measures of balance, for the Activities-specific Balance Confidence (ABC) Scale and the Modified Fall Efficacy Scale (MFES) as measures of balance confidence, and for over-ground spatiotemporal gait parameters at comfortable gait speed (CGS) and fast gait speed (FGS).

METHODS

Twenty ambulant adults with CP (mean age 32.7 years), GMFCS-E&R Levels I and II, were tested twice within an average of 10 days. Test-retest reliability was evaluated using intra-class correlation coefficients (ICC_2,1), and MDC₉₅ values were calculated using standard error of measurement values.

RESULTS

The test-retest reliability of most outcome measures was good to excellent. ICC values were: BESTest = 0.99, BESTest sections 0.88 to 0.98, FSST = 0.91, ABC=0.86, MFES = 0.9, CGS = 0.88, and FGS = 0.98. MDC values were: BESTest total = 4.9%, BESTest sections 8.7%-21.2%, FSST = 3.7 s, ABC = 18%, MFES = 1 point, CGS = 0.26 m/s, and FGS = 0.14 m/s. Most outcome scores were broadly distributed over scales ranges.

SIGNIFICANCE

Adults with CP demonstrated stable test-retest performance on the selected measures. These measures could be useful to assess balance and gait of adults with CP. The MDC values can help evaluate whether observed changes exceed the expected random test-retest variations.

Proposal of a new conceptual gait model for patients with Parkinson's disease based on factor analysis

BACKGROUND

Gait impairment is a risk factor for falls in patients with Parkinson's disease (PD). Gait can be conveniently assessed by electronic walkways, but there is need to select which spatiotemporal gait variables are useful for assessing gait in PD. Existing models for gait variables developed in healthy subjects and patients with PD show some methodological shortcomings in their validation through exploratory factor analysis (EFA), and were never confirmed by confirmatory factor analysis (CFA). The aims of this study were (1) to create a new model of gait for PD through EFA, (2) to analyze the factorial structure of our new model and compare it with existing models through CFA.

RESULTS

From the 37 variables initially considered in 250 patients with PD, 10 did not show good-to-excellent reliability and were eliminated, while further 19 were eliminated after correlation matrix and Kaiser-Meyer-Olkin measure. The remaining eight variables underwent EFA and three factors emerged: pace/rhythm, variability, and asymmetry. Structural validity of our new model was then examined with CFA, using the structural equation modeling. After some modifications, suggested by the Modification Indices, we obtained a final model that showed an excellent fit. In contrast, when the structure of previous models of gait was analyzed, no model achieved convergence with our sample of patients.

CONCLUSIONS

Our model for spatiotemporal gait variables of patients with PD is the first to be developed through an accurate EFA and confirmed by CFA. It contains eight gait variables divided into three factors and shows an excellent fit. Reasons for the non-convergence of other models could be their inclusion of highly inter-correlated or low-reliability variables or could be possibly due to the fact that they did not use more recent methods for determining the number of factors to extract.

Immediate effects of a novel walking assist device with auxiliary illuminator on patients after acute strokes

Background:

Many patients after acute stage of stroke are present with abnormal gait pattern due to weakness or hypertonicity of the affected limbs. Facilitation of normal gait is a primary goal of rehabilitation on these patients.

Objective:

We aimed to investigate whether walking assist device with auxiliary illuminator (quad-cane with laser) providing visual feedback during ambulation could improve parameters of gait cycle immediately among patients with subacute and chronic stroke.

Methods:

This was a cross-sectional study and 30 participants (male 23, female 7, group 1) with mean age 60.20±11.12 years were recruited. Among them, 22 used ankle-foot orthosis [(AFO), group 2] and 8 did not use AFO (group 3) at usual walking. All the participants walked along a strait corridor with even surface for 20 m without and with using a quad-cane with laser, respectively. A gait analyzer (Reha-Watch1 system) was used to measure the changes of the parameters of gait cycle, including stride length, cadence, gait speed, stance phase, swing phase, duration of single support and double support, the angle between toes and the ground at the time of toe-off (the toe-off angle) and the angle between calcaneus and the ground at the time of heel-strike (the heel-strike angle), before and with the use of a quad-cane with laser.

Results:

The increase in the heel-strike angle reached a significant difference in groups 1 2, and 3 (p=0.02,<0.01, and =0.05, respectively). However, the stride length, the gait speed, the cadence, percentage of the stance phase, swing phase, single-support phase, and double-support phase in a gait cycle, and the toe-off angle showed no significant change with the use of quad-cane with laser.

Conclusion:

Patients after acute stroke had an immediate and significant increase in the heel-stroke angle by using a quad-cane with laser during ambulation, which might help the patients to reduce knee hyperextension moment and lessen the pressure of heel at loading phase.

Novel gait training alters functional brain connectivity during walking in chronic stroke patients: a randomized controlled pilot trial

Background

A recent study has demonstrated that a turning-based treadmill program yields greater improvements in gait speed and temporal symmetry than regular treadmill training in chronic stroke patients. However, it remains unknown how this novel and challenging gait training shapes the cortico-cortical network and cortico-spinal network during walking in chronic stroke patients. The purpose of this study was to examine how a novel type of gait training, which is an unfamiliar but effective task for people with chronic stroke, enhances brain reorganization.

Methods

Subjects in the experimental and control groups received 30 min of turning-based treadmill training and regular treadmill training, respectively. Cortico-cortical connectivity and cortico-muscular connectivity during walking and gait performance were assessed before and after completing the 12-session training.

Results

Eighteen subjects (n = 9 per group) with a mean age of 52.5 ± 9.7 years and an overground walking speed of 0.61 ± 0.26 m/s consented and participated in this study. There were significant group by time interactions for gait speed, temporal gait symmetry, and cortico-cortical connectivity as well as cortico-muscular connectivity in walk-related frequency (24–40 Hz) over the frontal-central-parietal areas. Compared with the regular treadmill training, the turning-based treadmill training resulted in greater improvements in these measures. Moreover, the increases in cortico-cortical connectivity and cortico-muscular connectivity while walking were associated with improvements in temporal gait symmetry.

Conclusions

Our findings suggest this novel turning-based treadmill training is effective for enhancing brain functional reorganization underlying cortico-cortical and corticomuscular mechanisms and thus may result in gait improvement in people with chronic stroke.

Trial registration

ACTRN12617000190303. Registered 3 February 2017, retrospectively registered.

The Presence of a Paretic Propulsion Reserve During Gait in Individuals Following Stroke

BACKGROUND

The residual hemiparesis after stroke results in a unilateral reduction in propulsive force during gait. Prior work has suggested the presence of a propulsive reserve in the paretic limb.

OBJECTIVE

The purpose of this study was to quantify the paretic propulsive reserve in individuals poststroke and to determine the biomechanical mechanism underlying the generation of additional paretic propulsive limb force.

METHODS

Ten individuals with chronic hemiparesis poststroke walked on a treadmill against an impeding force (ascending 0% to 10% body weight [BW], in 2.5% BW increments, followed by descending 10% to 0% BW, also in 2.5% BW increments) applied to the body's center of mass. The resulting propulsive forces were measured bilaterally and compared between impeding force levels. We then assessed potential mechanisms (trailing limb angle and plantarflexion moment) underlying the changes in propulsion.

RESULTS

Overall, peak paretic propulsive force increased by 92% and the paretic propulsive impulse increased by 225%, resulting in a significant increase in the paretic limb's contribution to propulsion. Participants continued to produce increased paretic propulsion on removal of the impeding force. The trailing limb angle contributed significantly to the increase in paretic propulsion, whereas the plantarflexion moment did not.

CONCLUSIONS

Participants exhibited a robust propulsive reserve on the paretic limb, suggesting that there is untapped potential that can be exploited through rehabilitation to improve gait recovery. The increase in propulsive symmetry indicates that a greater response was observed by the paretic limb rather than increased compensation by the nonparetic limb.

The effect of unilateral blood flow restriction on temporal and spatial gait parameters

Blood flow restriction walking (BFR-W) is becoming more frequently used in aerobic and strength training and it has been proposed that BFR-W can be used in clinical populations. BFR-W may change gait stability yet few studies have assessed gait changes during or following BFR-W. The aim of this study was to assess if spatial-temporal gait parameters change during and following BFR-W. Twenty-four participants completed two walking sessions (>48-hours apart); 1) Unilateral BFR-W applied at the dominant thigh, 2) walking without BFR. In each session participants performed a 5-min warmup, 15-min walking intervention and 10-min active recovery. The warmup and active recovery were performed without BFR on both days. Measurements were attained at baseline, during the intervention and post-intervention using the GAITRite®. Linear mixed models were applied to each measured variable. Fixed factors were timepoint (warmup, intervention, and active recovery), condition (BFR-W and control walking) and condition × timepoint. Random factors were subject and subject × condition. Participants took shorter (3.2-cm (mean difference), CI_95%: 0.8–5.6-cm) and wider strides (1.4-cm, CI_95%: 0.9–1.9-cm) during BFR-W. For single leg measures, participants took shorter steps (2.8-cm, CI_95%: 1.7–4.0-cm) with a faster single support time (7.5-ms, CI_95%: 2.9–12.0-ms) on the non-dominant (unoccluded) leg during BFR-W compared to the non-dominant leg during control walking. There were no differences in step length and single support time between the dominant (occluded) leg during BFR-W compared to the dominant leg during control walking. There were no significant changes in velocity, cadence or double support time between BFR-W and control walking (P > 0.05). BFR-W caused small transient changes to several gait parameters. These changes should be considered when using BFR-W in clinical populations.

A wearable resistive robot facilitates locomotor adaptations during gait

BACKGROUND

Robotic-resisted treadmill walking is a form of task-specific training that has been used to improve gait function in individuals with neurological injury, such as stroke, spinal cord injury, or cerebral palsy. Traditionally, these devices use active elements (e.g., motors or actuators) to provide resistance during walking, making them bulky, expensive, and less suitable for overground or in-home rehabilitation. We recently developed a low-cost, wearable robotic brace that generates resistive torques across the knee joint using a simple magnetic brake. However, the possible effects of training with this device on gait function in a clinical population are currently unknown.

OBJECTIVE

The purpose of this study was to test the acute effects of resisted walking with this device on kinematics, muscle activation patterns, and gait velocity in chronic stroke survivors.

METHODS

Six stroke survivors wore the resistive brace and walked on a treadmill for 20 minutes (4×5 minutes) at their self-selected walking speed while simultaneously performing a foot trajectory-tracking task to minimize stiff-knee gait. Electromyography, sagittal plane gait kinematics, and overground gait velocity were collected to evaluate the acute effects of the device on gait function.

RESULTS

Robotic-resisted treadmill training resulted in a significant increase in quadriceps and hamstring EMG activity during walking. Significant aftereffects (i.e., improved joint excursions) were also observed on the hip and knee kinematics, which persisted for several steps after training. More importantly, training resulted in significant improvements in overground gait velocity. These results were consistent in all the subjects tested.

CONCLUSION

This study provides preliminary evidence indicating that robotic-resisted treadmill walking using our knee brace can result in meaningful biomechanical aftereffects that translate to overground walking.

Randomized controlled trial of robot-assisted gait training with dorsiflexion assistance on chronic stroke patients wearing ankle-foot-orthosis

BACKGROUND

Robot-assisted ankle-foot-orthosis (AFO) can provide immediate powered ankle assistance in post-stroke gait training. Our research team has developed a novel lightweight portable robot-assisted AFO which is capable of detecting walking intentions using sensor feedback of wearer's gait pattern. This study aims to investigate the therapeutic effects of robot-assisted gait training with ankle dorsiflexion assistance.

METHODS

This was a double-blinded randomized controlled trial. Nineteen chronic stroke patients with motor impairment at ankle participated in 20-session robot-assisted gait training for about five weeks, with 30-min over-ground walking and stair ambulation practices. Robot-assisted AFO either provided active powered ankle assistance during swing phase in Robotic Group (n = 9), or torque impedance at ankle joint as passive AFO in Sham Group (n = 10). Functional assessments were performed before and after the 20-session gait training with 3-month Follow-up. Primary outcome measure was gait independency assessed by Functional Ambulatory Category (FAC). Secondary outcome measures were clinical scores including Fugl-Meyer Assessment (FMA), Modified Ashworth Scale (MAS), Berg Balance Scale (BBS), Timed 10-Meter Walk Test (10MWT), Six-minute Walk Test (SMWT), supplemented by gait analysis. All outcome measures were performed in unassisted gait after patients had taken off the robot-assisted AFO. Repeated-measures analysis of covariance was conducted to test the group differences referenced to clinical scores before training.

RESULTS

After 20-session robot-assisted gait training with ankle dorsiflexion assistance, the active ankle assistance in Robotic Group induced changes in gait pattern with improved gait independency (all patients FAC ≥ 5 post-training and 3-month follow-up), motor recovery, walking speed, and greater confidence in affected side loading response (vertical ground reaction force + 1.49 N/kg, peak braking force + 0.24 N/kg) with heel strike instead of flat foot touch-down at initial contact (foot tilting + 1.91°). Sham Group reported reduction in affected leg range of motion (ankle dorsiflexion - 2.36° and knee flexion - 8.48°) during swing.

CONCLUSIONS

Robot-assisted gait training with ankle dorsiflexion assistance could improve gait independency and help stroke patients developing confidence in weight acceptance, but future development of robot-assisted AFO should consider more lightweight and custom-fit design.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02471248 . Registered 15 June 2015 retrospectively registered.

Cortical disconnection of the ipsilesional primary motor cortex is associated with gait speed and upper extremity motor impairment in chronic left hemispheric stroke

Advances in neuroimaging have enabled the mapping of white matter connections across the entire brain, allowing for a more thorough examination of the extent of white matter disconnection after stroke. To assess how cortical disconnection contributes to motor impairments, we examined the relationship between structural brain connectivity and upper and lower extremity motor function in individuals with chronic stroke. Forty-three participants [mean age: 59.7 (±11.2) years; time poststroke: 64.4 (±58.8) months] underwent clinical motor assessments and MRI scanning. Nonparametric correlation analyses were performed to examine the relationship between structural connectivity amid a subsection of the motor network and upper/lower extremity motor function. Standard multiple linear regression analyses were performed to examine the relationship between cortical necrosis and disconnection of three main cortical areas of motor control [primary motor cortex (M1), premotor cortex (PMC), and supplementary motor area (SMA)] and motor function. Anatomical connectivity between ipsilesional M1/SMA and the (1) cerebral peduncle, (2) thalamus, and (3) red nucleus were significantly correlated with upper and lower extremity motor performance (P ≤ 0.003). M1-M1 interhemispheric connectivity was also significantly correlated with gross manual dexterity of the affected upper extremity (P = 0.001). Regression models with M1 lesion load and M1 disconnection (adjusted for time poststroke) explained a significant amount of variance in upper extremity motor performance (R²  = 0.36-0.46) and gait speed (R²  = 0.46), with M1 disconnection an independent predictor of motor performance. Cortical disconnection, especially of ipsilesional M1, could significantly contribute to variability seen in locomotor and upper extremity motor function and recovery in chronic stroke. Hum Brain Mapp 39:120-132, 2018. © 2017 Wiley Periodicals, Inc.

Stepping to the Beat: Feasibility and Potential Efficacy of a Home-Based Auditory-Cued Step Training Program in Chronic Stroke

Background

Hemiparesis after stroke typically results in a reduced walking speed, an asymmetrical gait pattern and a reduced ability to make gait adjustments. The purpose of this pilot study was to investigate the feasibility and preliminary efficacy of home-based training involving auditory cueing of stepping in place.

Methods

Twelve community-dwelling participants with chronic hemiparesis completed two 3-week blocks of home-based stepping to music overlaid with an auditory metronome. Tempo of the metronome was increased 5% each week. One 3-week block used a regular metronome, whereas the other 3-week block had phase shift perturbations randomly inserted to cue stepping adjustments.

Results

All participants reported that they enjoyed training, with 75% completing all training blocks. No adverse events were reported. Walking speed, Timed Up and Go (TUG) time and Dynamic Gait Index (DGI) scores (median [inter-quartile range]) significantly improved between baseline (speed = 0.61 [0.32, 0.85] m⋅s⁻¹; TUG = 20.0 [16.0, 39.9] s; DGI = 14.5 [11.3, 15.8]) and post stepping training (speed = 0.76 [0.39, 1.03] m⋅s⁻¹; TUG = 16.3 [13.3, 35.1] s; DGI = 16.0 [14.0, 19.0]) and was maintained at follow-up (speed = 0.75 [0.41, 1.03] m⋅s⁻¹; TUG = 16.5 [12.9, 34.1] s; DGI = 16.5 [13.5, 19.8]).

Conclusion

This pilot study suggests that auditory-cued stepping conducted at home was feasible and well-tolerated by participants post-stroke, with improvements in walking and functional mobility. No differences were detected between regular and phase-shift training with the metronome at each assessment point.

The role of movement errors in modifying spatiotemporal gait asymmetry post stroke: a randomized controlled trial

OBJECTIVE

Current rehabilitation to improve gait symmetry following stroke is based on one of two competing motor learning strategies: minimizing or augmenting symmetry errors. We sought to determine which of those motor learning strategies best improves overground spatiotemporal gait symmetry.

DESIGN

Randomized controlled trial.

SETTING

Rehabilitation research lab.

SUBJECTS

In all, 47 participants (59 ± 12 years old) with chronic hemiparesis post stroke and spatiotemporal gait asymmetry were randomized to error augmentation, error minimization, or conventional treadmill training (control) groups.

INTERVENTIONS

To augment or minimize asymmetry on a step-by-step basis, we developed a responsive, "closed-loop" control system, using a split-belt instrumented treadmill that continuously adjusted the difference in belt speeds to be proportional to the patient's current asymmetry.

MAIN MEASURES

Overground spatiotemporal asymmetries and gait speeds were collected prior to and following 18 training sessions.

RESULTS

Step length asymmetry reduced after training, but stance time did not. There was no group × time interaction. Gait speed improved after training, but was not affected by type of asymmetry, or group. Of those who trained to modify step length asymmetry, there was a moderately strong linear relationship between the change in step length asymmetry and the change in gait speed.

CONCLUSION

Augmenting errors was not superior to minimizing errors or providing only verbal feedback during conventional treadmill walking. Therefore, the use of verbal feedback to target spatiotemporal asymmetry, which was common to all participants, appears to be sufficient to reduce step length asymmetry. Alterations in stance time asymmetry were not elicited in any group.

Efficacy of Aquatic Treadmill Training on Gait Symmetry and Balance in Subacute Stroke Patients

Objective

To determine the efficacy of aquatic treadmill training (ATT) as a new modality for stroke rehabilitation, by assessing changes in gait symmetry, balance function, and subjective balance confidence for the paretic and non-paretic leg in stroke patients.

Methods

Twenty-one subacute stroke patients participated in 15 intervention sessions of aquatic treadmill training. The Comfortable 10-Meter Walk Test (CWT), spatiotemporal gait parameters, Berg Balance Scale (BBS), and Activities-specific Balance Confidence scale (ABC) were assessed pre- and post-interventions.

Results

From pre- to post-intervention, statistically significant improvements were observed in the CWT (0.471±0.21 to 0.558±0.23, p<0.001), BBS (39.66±8.63 to 43.80±5.21, p<0.001), and ABC (38.39±13.46 to 46.93±12.32, p<0.001). The step-length symmetry (1.017±0.25 to 0.990±0.19, p=0.720) and overall temporal symmetry (1.404±0.36 to 1.314±0.34, p=0.218) showed improvement without statistical significance.

Conclusion

ATT improves the functional aspects of gait, including CWT, BBS and ABC, and spatiotemporal gait symmetry, though without statistical significance. Further studies are required to examine and compare the potential benefits of ATT as a new modality for stroke therapy, with other modalities.

Validity and repeatability of inertial measurement units for measuring gait parameters

Inertial measurement units (IMUs) are small wearable sensors that have tremendous potential to be applied to clinical gait analysis. They allow objective evaluation of gait and movement disorders outside the clinic and research laboratory, and permit evaluation on large numbers of steps. However, repeatability and validity data of these systems are sparse for gait metrics. The purpose of this study was to determine the validity and between-day repeatability of spatiotemporal metrics (gait speed, stance percent, swing percent, gait cycle time, stride length, cadence, and step duration) as measured with the APDM Opal IMUs and Mobility Lab system. We collected data on 39 healthy subjects. Subjects were tested over two days while walking on a standard treadmill, split-belt treadmill, or overground, with IMUs placed in two locations: both feet and both ankles. The spatiotemporal measurements taken with the IMU system were validated against data from an instrumented treadmill, or using standard clinical procedures. Repeatability and minimally detectable change (MDC) of the system was calculated between days. IMUs displayed high to moderate validity when measuring most of the gait metrics tested. Additionally, these measurements appear to be repeatable when used on the treadmill and overground. The foot configuration of the IMUs appeared to better measure gait parameters; however, both the foot and ankle configurations demonstrated good repeatability. In conclusion, the IMU system in this study appears to be both accurate and repeatable for measuring spatiotemporal gait parameters in healthy young adults.

Gait training with Hybrid Assistive Limb enhances the gait functions in subacute stroke patients: A pilot study

BACKGROUND

The robotic Hybrid Assistive Limb (HAL) provides motion according to the wearer's voluntary activity. HAL training effects on walking speed and capacity have not been clarified in subacute stroke.

OBJECTIVES

To determine improvement in walking ability by HAL and the most effective improvement measure for use in future large-scale trials.

METHODS

Sixteen first-ever hemiplegic stroke patients completed at least 20 sessions over 5 weeks. Per session, the experimental group received no more than 20 min of gait training with HAL (HT) and 40 min of conventional physiotherapy, whereas the control group received at least 60 min of conventional physiotherapy. Primary outcome was maximum walking speed (MWS).

RESULTS

The change in MWS from baseline at week 5 was 11.6±10.6 m/min (HAL group) and 2.2±4.1 m/min (control group) (adjusted mean difference = 9.24 m/min, 95% confidence interval 0.48-18.01, P = 0.040). In HAL subjects there were significant increases in Self-selected walking speed (SWS; a secondary outcome) and in step length (a secondary outcome) at MWS and SWS compared with controls.

CONCLUSIONS

HT improved walking speed in hemiplegic sub-acute stroke patients. In future, randomized controlled trials are needed to confirm the utility of HT.

Outcomes of Botulinum Toxin Type A for equinovarus deformity in patients with CVA: A case series

BACKGROUND

There is evidence that Botulinum Toxin-A (BTX-A) reduces focal spasticity associated with equinovarus to improve gait in patients poststroke. However, there is little research examining whether gait improvements are maintained after the effectiveness period of BTX-A injections. The purpose of this observational study was to determine whether there was a difference in gait parameters in three patients before BTX-A injection versus four and ten weeks after.

CASE SERIES

Three women, ages 63, 60, and 42 postischemic stroke with hemiparesis and equinovarus underwent measurements for: plantar flexor spasticity, ankle dorsiflexion ROM, temporal-spatial gait parameters, and gait endurance. All participants improved in ankle ROM. At week 10, spasticity had returned to initial measurement levels in participants A and C. Base of support and step length symmetry ratios did not improve following injections. Participants A and B, who received physical therapy during the study, showed modest gains in gait endurance and velocity.

CONCLUSION

Although BTX-A injections improved spasticity, this improvement did not translate to gait outcomes. Addition of physical therapy interventions appeared to improve gait outcomes in this case series. We suggest future randomized control studies to compare effects of physical therapy alone to BTX-A combined with physical therapy on gait outcomes.

Gait Training With Visual Feedback and Proprioceptive Input to Reduce Gait Asymmetry in Adults With Cerebral Palsy: A Case Series

PURPOSE

The purpose of this case series was to investigate the feasibility of using visual feedback on gait asymmetry during gait retraining and whether this leads to reduced asymmetry, improvement in gait speed, cost of walking, and dynamic balance in ambulant adults with cerebral palsy (CP).

METHODS

Five adults with CP, who were ambulatory and had step length or stance time asymmetry, trained for 18 sessions on a split-belt treadmill with concurrent visual feedback from a virtual environment. Training also included overground gait training to encourage transfer of learning.

RESULTS

All participants reduced gait asymmetry and improved on outcomes at posttest and follow-up.

CONCLUSIONS

Outcome measures and training protocols were feasible in this sample of convenience of adults with CP who were ambulatory and who did not have visual impairment. The adults with CP in this study demonstrated individual improvements in gait and balance following training.

Inter-session agreement and reliability of the Global Gait Asymmetry index in healthy adults

There has been a growing effort in restoring gait symmetry in clinical conditions associated with pronounced gait asymmetry. A prerequisite to achieve this is that the chosen approach can accurately assess symmetry and detect/impose changes that exceed the natural day to day variability. Global symmetry indices are superior to local and discrete indices because they capture the patient's overall gait symmetry. However, their repeatability is unknown. This study assessed the inter-session agreement and reliability of the Global Gait Asymmetry index. Twenty-three healthy individuals participated in two 3D gait analyses, performed approximately one week apart. The 95% limits of agreement, standard error of measurement, smallest detectable change, and intraclass correlation coefficient were analysed. The obtained values showed this index has poor agreement and reliability between sessions. Therefore, it cannot be used to assess the patient's progress overtime nor to compare symmetry levels among groups.

Efficacy of two injection-site localisation techniques for botulinum toxin injections: a single-blind, crossover, randomised trial protocol among adults with hemiplegia due to stroke

INTRODUCTION

Botulinum toxin injections are an effective treatment for limb spasticity following stroke. Different tracking techniques are used for this purpose: palpation, electrostimulation, electromyography and ultrasound. Yet very few studies have compared these different techniques, and none has successfully proved the superior efficacy of ultrasound-guided injections compared to another tracking method. The primary objective of our study was therefore to compare the efficacy of botulinum toxin injections depending on the tracking technique used: ultrasound versus electrostimulation.

METHODS AND ANALYSIS

This is a clinical, single-centre, prospective, interventional, single-blind, crossover, randomised trial. In total, 30 patients aged between 18 and 80 years presenting with triceps surae spasticity (evaluated >1 on the modified Ashworth scale) associated with hemiplegia sequelae due to stroke will be included. The patients will be selected among those who attend for consultation the Physical Medicine and Rehabilitation Department of the Clermont-Ferrand University Hospital. One group will receive the abobotulinumtoxinA (BoNT-A) injection guided by electrostimulation then ultrasound, and the second group's botulinum toxin injections will be guided by ultrasound then electrostimulation. For each patient, the duration of study participation is 5 months. The primary end point is variation in passive ankle dorsiflexion range of motion at slow and high speeds (Tardieu scale) with the knee straight.

ETHICS AND DISSEMINATION

This study received ethics approval form the CPP of Rhônes-Alpes region. Results will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT01935544; pre-results.

Test-Retest Reliability and Concurrent Validity of a Single Tri-Axial Accelerometer-Based Gait Analysis in Older Adults with Normal Cognition

Objective

We investigated the concurrent validity and test-retest reliability of spatio-temporal gait parameters measured with a single tri-axial accelerometer (TAA), determined the optimal number of steps required for obtaining acceptable levels of reliability, and compared the validity and reliability of the estimated gait parameters across the three reference axes of the TAA.

Methods

A total of 82 cognitively normal elderly participants walked around a 40-m long round walkway twice wearing a TAA at their center of body mass. Gait parameters such as cadence, gait velocity, step time, step length, step time variability, and step time asymmetry were estimated from the low pass-filtered signal of the TAA. The test-retest reliability and concurrent validity with the GAITRite^® system were evaluated for the estimated gait parameters.

Results

Gait parameters using signals from the vertical axis showed excellent reliability for all gait parameters; the intraclass correlation coefficient (ICC) was 0.79–0.90. A minimum of 26 steps and 14 steps were needed to achieve excellent reliability in step time variability and step time asymmetry, respectively. A strong level of agreement was seen for the basic gait parameters between the TAA and GAITRite^Ⓡ (ICC = 0.91–0.96).

Conclusions

The measurement of gait parameters of elderly individuals with normal cognition using a TAA placed on the body’s center of mass was reliable and showed superiority over the GAITRite^Ⓡ with regard to gait variability and asymmetry. The TAA system was a valid tool for measuring basic gait parameters. Considering its wearability and low price, the TAA system may be a promising alternative to the pressure sensor walkway system for measuring gait parameters.

Randomized comparison trial of gait training with and without compelled weight-shift therapy in individuals with chronic stroke

Objective:

To compare the effects of gait training combined with compelled weight-shift therapy and gait training alone on velocity and gait symmetry in patients with chronic stroke.

Design:

Single-blind randomized controlled trial.

Participants:

Patients ( N=28) with chronic stroke and stance asymmetry toward the non-paretic side.

Interventions:

Six weeks of gait training combined with compelled weight-shift therapy via a shoe lift applied under the non-paretic leg (experimental group, n=14) or gait training alone (control group, n=14).

Main measures:

Percentage of total body weight carried by the paretic limb, gait velocity and gait spatiotemporal symmetry ratios including step symmetry, stance symmetry, swing symmetry and overall temporal symmetry.

Results:

When comparing the two groups, weight bearing on the affected side increased more significantly in experimental group than in control group (40.14±3.77, 38.28±4.06) after the end of treatment and also after a three-month follow-up (44.42±3.5, 38.5±3.77) (P<0.05). Among the experimental and control groups, there were no significant differences of gait velocity (cm/s) after six weeks of treatment (49.82±16.82, 42.66±18.75) and also after a three-month follow-up (50.94±16.27, 41.66±17.58) ( P>0.05). There were no significant differences of gait spatiotemporal symmetry ratios including step symmetry, stance symmetry, swing symmetry and overall temporal symmetry between the two groups after six weeks of treatment and also at three-month follow-up ( P>0.05).

Conclusions:

This study did not confirm that the effect of gait training combined with compelled body weight shift therapy was better than gait training alone on improving velocity and gait symmetry in patients with chronic stroke.