Developing a Gait Enhancing Mobile Shoe to Alter Over-Ground Walking Coordination

One-year retention of gait speed improvement in stroke survivors after treatment with a wearable home-use gait device

Background

Gait impairments after stroke are associated with numerous physical and psychological consequences. Treatment with the iStride® gait device has been shown to facilitate improvements to gait function, including gait speed, for chronic stroke survivors with hemiparesis. This study examines the long-term gait speed changes up to 12 months after treatment with the gait device.

Methods

Eighteen individuals at least one-year post-stroke completed a target of 12, 30-minute treatment sessions with the gait device in their home environment. Gait speed was measured at baseline and five follow-up sessions after the treatment period: one  week, one  month, three months, six months, and 12 months. Gait speed changes were analyzed using repeated-measures ANOVA from baseline to each follow-up time frame. Additional analysis included comparison to the minimal clinically important difference (MCID), evaluation of gait speed classification changes, and review of subjective questionnaires.

Results

Participants retained an average gait speed improvement >0.21 m/s compared to baseline at all post-treatment time frames. Additionally, 94% of participants improved their gait speed beyond the MCID during one or more post-treatment measurements, and 88% subjectively reported a gait speed improvement.

Conclusion

Treatment with the gait device may result in meaningful, long-term gait speed improvement for chronic stroke survivors with hemiparetic gait impairments.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT03649217, identifier NCT03649217.

Wearable gait device for stroke gait rehabilitation at home

BACKGROUND

Hemiparesis is a common disabling consequence of stroke that leads to abnormal gait patterns marked by asymmetries in step length, stance, and swing phases. Asymmetric gait patterns are correlated with decreased gait velocity and increased susceptibility to falls that can lead to serious injuries and hospitalizations.

OBJECTIVE

In this single group, before and after study, treatment with the iStride^TM gait device, designed to improve the gait patterns of individuals with hemiparesis, is adapted to the home environment. Previously tested in clinical settings, this study investigates if using the iStride^TM gait device within the home environment can provide safe and effective gait treatment for individuals with hemiparetic gait impairments caused by stroke.

METHODS

Twelve 30-minute sessions of walking on the device were administered in each participant's home environment. Twenty-one participants who were more than one-year post-stroke received the treatment. The Ten-Meter Walk Test, Timed Up and Go Test, Berg Balance Scale, Functional Gait Assessment, and Stroke Specific Quality of Life Scale were performed before and one week after treatment. Safety, treatment plan compliance, and subjective responses were also recorded during the study period.

RESULTS

Results demonstrate statistically significant improvement on all five outcome measures from before treatment to one week after the last treatment session (p < 0.01) using two-tailed paired t-tests. 76% of participants improved beyond the small meaningful change or minimal detectable change on three or more outcome measures. 67% of participants improved clinically in gait speed and on at least one of the fall risk assessment inventories. 81% of the participants were able to perform the treatment in their home without assistance before the end of week three.

CONCLUSIONS

The results indicate that the iStride^TM gait device can facilitate effective, safe, and home-accessible gait treatment opportunities for individuals with hemiparesis from stroke.

Human Gait Analysis Metric for Gait Retraining

The combined gait asymmetry metric (CGAM) provides a method to synthesize human gait motion. The metric is weighted to balance each parameter's effect by normalizing the data so all parameters are more equally weighted. It is designed to combine spatial, temporal, kinematic, and kinetic gait parameter asymmetries. It can also combine subsets of the different gait parameters to provide a more thorough analysis. The single number quantifying gait could assist robotic rehabilitation methods to optimize the resulting gait patterns. CGAM will help define quantitative thresholds for achievable balanced overall gait asymmetry. The study presented here compares the combined gait parameters with clinical measures such as timed up and go (TUG), six-minute walk test (6MWT), and gait velocity. The comparisons are made on gait data collected on individuals with stroke before and after twelve sessions of rehabilitation. Step length, step time, and swing time showed a strong correlation to CGAM, but the double limb support asymmetry has nearly no correlation with CGAM and ground reaction force asymmetry has a weak correlation. The CGAM scores were moderately correlated with TUG and strongly correlated to 6MWT and gait velocity.

Relearning functional and symmetric walking after stroke using a wearable device: a feasibility study

BACKGROUND

Gait impairment is a common consequence of stroke and typically involves a hemiparetic or asymmetric walking pattern. Asymmetric gait patterns are correlated with decreased gait velocity and efficiency as well as increased susceptibility to serious falls and injuries.

RESEARCH QUESTION

This paper presents an innovative device worn on a foot for gait rehabilitation post stroke. The device generates a backward motion to the foot, which is designed to exaggerate the existing step length asymmetry while walking over ground. We hypothesize this motion will decrease gait asymmetry and improve functional walking in individuals with chronic stroke.

METHODS

Six participants with chronic stroke, more than one year post stroke, received four weeks of gait training with three sessions per week. Each session included 30 min of walking over ground using the wearable device. Gait symmetry and functional walking were assessed before and after training.

RESULTS

All participants improved step length symmetry, and four participants improved double limb support symmetry. All participants improved on all three functional outcomes (gait velocity, Timed Up and Go Test, and 6-Minute Walk Test), and five participants improved beyond the minimal detectable change or meaningful change in at least one functional outcome.

CONCLUSION

The results indicate that the presented device may help improve stroke patients' walking ability and warrant further study. A gait training approach using this new device may enable and expand long-term continuous gait rehabilitation outside the clinic following stroke.

TRIAL REGISTRATION

NCT02185404. Registered July 9, 2014, https://clinicaltrials.gov/ct2/show/NCT02185404.

A Perturbation Mechanism for Investigations of Phase-Dependent Behavior in Human Locomotion

Bipedal locomotion is a popular area of study across multiple fields (e.g., biomechanics, neuroscience and robotics). Different hypotheses and models have tried explaining how humans achieve stable locomotion. Perturbations that produce shifts in the nominal periodic orbit of the joint kinematics during locomotion could inform about the manner in which the human neuromechanics represent the phase of gait. Ideally, this type of perturbation would modify the progression of the human subject through the gait cycle without deviating from the nominal kinematic orbits of the leg joints. However, there is a lack of publicly available experimental data with this type of perturbation. This paper presents the design and validation of a perturbation mechanism and an experimental protocol capable of producing phase-shifting perturbations of the gait cycle. The effects of this type of perturbation on the gait cycle are statistically quantified and analyzed in order to show that a clean phase shift in the gait cycle was achieved. The data collected during these experiments will be publicly available for the scientific community to test different hypotheses and models of human locomotion.

Comparison of the passive dynamics of walking on ground, tied-belt and split-belt treadmills, and via the Gait Enhancing Mobile Shoe (GEMS)

This research compares walking over ground, on a split-belt treadmill, on a tied-belt treadmill, and on the Gait Enhancing Mobile Shoe (GEMS) in both humans and simulated on a passive dynamic model. Passive Dynamic Walkers (PDW) have been researched for decades, yet only recently has the model been used significantly in gait rehabilitation. We aim to identify how well the two-dimensional PDW can be used as a kinematic approximation tool for gait analysis. In this work, the PDW was scaled according to an anthropomorphic human model. For comparison, measurements were taken of humans walking in the same four environments. For normal walking, the PDW was found to be a good approximation for symmetric and rhythmic hip position, foot position, and velocity profiles. Tied-belt and split-belt treadmill model estimations revealed that the PDW's lack of dorsiflexion, joint stiffness, and joint damping limited the comparison, however trends between the human and the model agreed. The kinematics of the GEMS showed good agreement in interlimb interactions indicating that the PDW can be used as a good kinematic predictor for the GEMS.