Gait Device Treatment Using Telehealth for Individuals With Stroke During the COVID-19 Pandemic: Nonrandomized Pilot Feasibility Study.

BACKGROUND: During the COVID-19 pandemic, rehabilitation providers and consumers adopted telehealth practices at unprecedented rates. Multiple prepandemic studies demonstrate the feasibility and comparable efficacy between in-clinic and remote treatment for certain impairments caused by stroke, such as upper extremity weakness and impaired motor function. However, less guidance has been available regarding gait assessment and treatment. Despite this limitation, safe and effective gait treatment is fundamental to optimizing health and well-being after stroke and should be considered a treatment priority, including during the COVID-19 pandemic. OBJECTIVE: This study explores the feasibility of using telehealth to deliver gait treatment using a wearable gait device, the iStride device, to stroke survivors during the 2020 pandemic. The gait device is used to treat hemiparetic gait impairments caused by stroke. The device alters the user's gait mechanics and creates a subtle destabilization of the nonparetic limb; therefore, supervision is required during its usage. Before the pandemic, treatment with the gait device had been provided in person to appropriate candidates using a combination of physical therapists and trained personnel. However, upon the emergence of the COVID-19 pandemic, in-person treatment was halted in adherence to pandemic guidelines. This study investigates the feasibility of 2 remote delivery treatment models with the gait device for stroke survivors. METHODS: Participants were recruited during the first half of 2020 after the onset of the pandemic and included 5 individuals with chronic stroke (mean age 72 years; 84 months post stroke). Four participants were previous gait device users who transitioned to the telehealth delivery model to continue their gait treatment remotely. The fifth participant performed all study-related activities, from recruitment through follow-up, remotely. The protocol included virtual training for the at-home care partner, followed by 3 months of remote treatment with the gait device. Participants were instructed to wear gait sensors during all treatment activities. To assess feasibility, we monitored the safety of the remote treatment, compliance with protocol activities, acceptability of the telehealth treatment delivery, and preliminary efficacy of the gait treatment. Functional improvement was measured using the 10-Meter Walk Test, the Timed Up and Go Test, and the 6-Minute Walk Test, and quality of life was assessed using the Stroke-Specific Quality of Life Scale. RESULTS: No serious adverse events occurred, and participants rated high acceptance of the telehealth delivery. Protocol compliance averaged 95% of treatment sessions, 100% of assessments, and 85% of sensor usage during treatment. After 3 months of treatment, the average improvement in each functional outcome exceeded the minimal clinically important difference or minimal detectable change value. CONCLUSIONS: Remote treatment delivery with the gait device appeared feasible with care partner support. Gait treatment using telehealth may be useful to offset negative immobility impacts for those requiring or preferring remote care during the pandemic or otherwise. TRIAL REGISTRATION: ClinicalTrials.gov NCT04434313; https://clinicaltrials.gov/ct2/show/NCT04434313.

A systematic literature review of ankle-foot orthosis and functional electrical stimulation foot-drop treatments for persons with multiple sclerosis.

Foot-drop is one of the most diagnosed and physically limiting symptoms persons with multiple sclerosis (pwMS) experience. Clinicians prescribe ankle-foot orthosis (AFO) and functional electrical stimulation (FES) devices to help alleviate the effects of foot drop, but it is unclear how their clinical and functional gait improvements compare given the user's level of disability, type of multiple sclerosis, walking environment, or desired physical activity. The research questions explored were what is the current state of AFO and FES research for pwMS? What are the prevailing research trends? What definitive clinical and functional device comparisons exist for pwMS? eight databases were systematically searched for relevant literature published between 2009 and 2021. The American Association of Orthotists and Prosthetists and Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines for systematic literature reviews were followed. A team of 3 researchers critically evaluated 17 articles that passed eligibility criteria. This review discusses the current state and trends of research, provides evidence statements on device effects, and recommends improvements for future studies. A meta-analysis would be informative, but study variability across the literature makes directly comparing AFO and FES device effects unreliable. This review contributes new and useful information to multiple sclerosis literature that can be used by both clinicians and researchers. Clinicians can use the provided insights to prescribe more effective, customized treatments, and other researchers can use them to evaluate and design future studies.

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.

Real-time feedback control of split-belt ratio to induce targeted step length asymmetry.

INTRODUCTION: Split-belt treadmill training has been used to assist with gait rehabilitation following stroke. This method modifies a patient's step length asymmetry by adjusting left and right tread speeds individually during training. However, current split-belt training approaches pay little attention to the individuality of patients by applying set tread speed ratios (e.g., 2:1 or 3:1). This generalization results in unpredictable step length adjustments between the legs. To customize the training, this study explores the capabilities of a live feedback system that modulates split-belt tread speeds based on real-time step length asymmetry. MATERIALS AND METHODS: Fourteen healthy individuals participated in two 1.5-h gait training sessions scheduled 1 week apart. They were asked to walk on the Computer Assisted Rehabilitation Environment (CAREN) split-belt treadmill system with a boot on one foot to impose asymmetrical gait patterns. Each training session consisted of a 3-min baseline, 10-min baseline with boot, 10-min feedback with boot (6% asymmetry exaggeration in the first session and personalized in the second), 5-min post feedback with boot, and 3-min post feedback without boot. A proportional-integral (PI) controller was used to maintain a specified step-length asymmetry by changing the tread speed ratios during the 10-min feedback period. After the first session, a linear model between baseline asymmetry exaggeration and post-intervention asymmetry improvement was utilized to develop a relationship between target exaggeration and target post-intervention asymmetry. In the second session, this model predicted a necessary target asymmetry exaggeration to replace the original 6%. This prediction was intended to result in a highly symmetric post-intervention step length. RESULTS AND DISCUSSION: Eleven out of 14 participants (78.6%) developed a successful relationship between asymmetry exaggeration and decreased asymmetry in the post-intervention period of the first session. Seven out of the 11 participants (63.6%) in this successful correlation group had second session post-intervention asymmetries of < 3.5%. CONCLUSIONS: The use of a PI controller to modulate split-belt tread speeds demonstrated itself to be a viable method for individualizing split-belt treadmill training.

Time Delay Affects Thermal Discrimination.

Time order errors have been investigated in several fields, and the time delay between subsequent stimuli in discrimination tasks is one example of such errors. However, the effect of these types of errors in thermal discrimination tasks is understudied. To evaluate the effect of inter-stimulus interval (ISI) on thermal perception, we used a discrimination task with a staircase method between two non-zero thermal stimuli. We found that JND ISI=0s was 3.10 and increased by 11.9% and 21.2% at JND ISI=3s and JND ISI=9s, respectively. Statistical analysis revealed that ISI was a statistically significant effect ( ) on thermal perception in our task. Future studies on thermal perception should keep the ISI consistent and report the time.

The Role of Spatial and Modality Cues on Visual and Haptic Memory.

This study investigates the ability to remember a sequence of stimuli in two basic conditions: haptic and visual. Participants rely on a combination of modal and/or spatial information to perform a memory task. For this purpose, an experimental setup was developed based on the "Simon Says" memory game. Individuals receive a series of sensory stimuli and need to remember the sequence and repeat it. The stimuli in visual conditions are colored or white lights, and the stimuli in haptic conditions are vibration, hot, cold, and skin stretch. Results demonstrate that participants retained longer sequences in spatial conditions compared to the modal conditions. It is also demonstrated that participants performed better in visual conditions compared to haptic conditions. Participants were able to retain more complex spatial patterns and remember them faster in visual conditions compared to haptic conditions. A spatial difficulty ranking system was developed, indicating how easily each spatial pattern can be retained visually and haptically.

Human-Human Connected Dyads Learning a Visuomotor Rotation in a Targeted Reaching Task.

Little is known about how two people physically coupled together (a dyad) can accomplish tasks. In a pilot study we tested how healthy inexperienced and experienced dyads learn to repeatedly reach to a target and stop while challenged with a 30 degree visuomotor rotation. We employed the Pantograph investigational device that haptically couples partners movements while providing cursor feedback, and we measured the amount and speed of learning to test a prevailing hypothesis: dyads with no experience learn faster than an experienced person coupled with a novice. We found significant straightening of movements for dyads in terms of amount of learning (2.662±0.102 cm and 2.576±0.024 cm for the novice-novice and novice-experienced groups) at rapid rates (time constants of 17.83 ± 2.85 and 18.17.17±6.72 movements), which was nearly half the learning time as solo individuals' studies. However, we found no differences between the novice-novice and experienced-novice groups, though retrospectively our power was only 3 percent. This pilot study demonstrates new opportunities to investigate the advantages of partner-facilitated learning with solely haptic communication which and can lead to insights on control in human physical interactions and can guide the design of future human-robot-human interaction systems.

Using genetic algorithms to uncover individual differences in how humans represent facial emotion.

Emotional facial expressions critically impact social interactions and cognition. However, emotion research to date has generally relied on the assumption that people represent categorical emotions in the same way, using standardized stimulus sets and overlooking important individual differences. To resolve this problem, we developed and tested a task using genetic algorithms to derive assumption-free, participant-generated emotional expressions. One hundred and five participants generated a subjective representation of happy, angry, fearful and sad faces. Population-level consistency was observed for happy faces, but fearful and sad faces showed a high degree of variability. High test-retest reliability was observed across all emotions. A separate group of 108 individuals accurately identified happy and angry faces from the first study, while fearful and sad faces were commonly misidentified. These findings are an important first step towards understanding individual differences in emotion representation, with the potential to reconceptualize the way we study atypical emotion processing in future research.

Superposition principle applies to human walking with two simultaneous interventions.

Gait rehabilitation therapies provide adjusted sensory inputs to modify and retrain walking patterns in an impaired gait. Asymmetric walking is a common gait abnormality, especially among stroke survivors. Physical therapy interventions using adaptation techniques (such as treadmill training, auditory stimulation, visual biofeedback, etc.) train gait toward symmetry. However, a single rehabilitation therapy comes up short of affecting all aspects of gait performance. Multiple-rehabilitation therapy applies simultaneous stimuli to affect a wider range of gait parameters and create flexible training regiments. Understanding gait responses to individual and jointly applied stimuli is important for developing improved and efficient therapies. In this study, 16 healthy subjects participated in a four-session experiment to study gait kinetics and spatiotemporal outcomes under training. Each session consisted of two stimuli, treadmill training and auditory stimulation, with symmetric or asymmetric ratios between legs. The study hypothesizes a linear model for gait response patterns. We found that the superposition principle largely applies to the gait response under two simultaneous stimuli. The linear models developed in this study fit the actual data from experiments with the r-squared values of 0.95 or more.

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 iStrideTM 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 iStrideTM 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 iStrideTM gait device can facilitate effective, safe, and home-accessible gait treatment opportunities for individuals with hemiparesis from stroke.

Haptic Coupling in Dyads Improves Motor Learning in a Simple Force Field.

In dyadic motor learning, pairs of people learn the same motion while their limbs are loosely coupled together using haptic devices. Such coupled learning has been shown to outperform solo learning (including robot-guided learning) for simple one-degree-of-freedom tasks. However, results from more complex tasks are limited and sometimes conflicting. We thus evaluated coupled learning in a two-degree-of-freedom tracking task where participants also had to compensate for a simple force field. Participant pairs were split into two groups: an experiment group that experienced a compliant haptic coupling between participants' hands and a control group that did not. The study protocol consisted of 70 repetitions of 18.9-second tracking trials: 10 initial solo trials with no coupling, 50 "learning" trials (where participants in the experiment group were coupled), and 10 final solo trials with no coupling. The experiment group (coupled) improved their solo tracking performance both in the presence (p = 0.008) and absence (p <; 0.001) of the force field; however, the control group (no coupling) only improved their solo performance in the absence of the force field (p <; 0.001) but not in the presence of the field (p = 0.81). This suggests that dyadic motor learning can outperform solo learning for two-dimensional tracking motions in the presence of a simple force field, though the mechanism by which learning is improved is not yet clear.Clinical Relevance-As motor learning is critical for applications such as motor rehabilitation, dyadic training could be used to achieve a better overall outcome and a faster learning speed in these applications compared to solo training.

Novel passive ankle-foot prosthesis mimics able-bodied ankle angles and ground reaction forces.

BACKGROUND: During gait, the human ankle both bends with ease and provides push-off forces that facilitate forward motion. The ankle is crucial for support, stabilization, and adapting to different slopes and terrains. Individuals with lower limb amputation require an ankle-foot prosthesis for basic mobility. METHODS: Inspired by the role of the ankle-foot in an able-bodied gait, the 3D printed Compliant and Articulating Prosthetic Ankle (CAPA) foot was designed. It consists of four articulating components connected by torsion springs and produces forces that are dependent on the ankle angle. Using the Computer Assisted Rehabilitation Environment, able-bodied individuals walked wearing a prosthetic simulator with the Solid Ankle Cushioned Heel foot, Renegade® AT, and multiple versions of the CAPA. These versions test compliant vs. stiff, small vs. large rocker radius, and pretension vs. none. We hypothesized that the CAPA would have larger ankle range of motion, push-off forces, and braking forces. FINDINGS: Compared to existing prostheses, the novel prosthesis exhibits greater and significantly different ankle range of motion and sagittal plane ground reaction forces than existing prostheses during gait. Nine out of ten individuals prefer the novel prosthesis to the existing prostheses, and there is a statistically significant difference in difficulty level ratings. INTERPRETATION: By providing a personalizable and passive alternative to existing designs, the CAPA could improve the quality of life for the growing number of individuals living with limb loss in the United States and around the world.

Walking assistance using crutches: A state of the art review.

Crutches are one of the most common ambulatory assistive devices. Using crutches encourages more physical activity than many other assistive devices, which has long-term health benefits. Recent advances have led to improvements in performance, but using crutches remains slower than normal walking, are energetically inefficient, cause additional strain on upper extremities, and often result in abrasions on the skin. Further improvements to address these deficiencies are needed but require an understanding of the crutch users' disabilities, different crutch gait patterns, associated biomechanics, and how the crutch design interacts with the user. It is important that research studies and designs take into account parameters from multiple ways of measuring performance in order for impaired users to achieve effective crutch walking. Many existing studies of crutches only analyze a subset of quantitative variables, so the overall impact of a design or modification is not fully assessed or comparable to other designs. Another important aspect is the user; each crutch type has specific characteristics that need to match the user's ability, physical fitness, and gait pattern. Pain and injuries on upper extremities should also be considered as an important factor in long-term users. A search was done to find research papers and related patents focusing on crutch design and usage. Papers that studied one or more of the following topics were included: effects of crutches on the gait parameter, types of crutch walking patterns, improving walking efficiency through crutch design, and identifying the important components when studying a gait. This review paper summarizes the effects of existing crutch types and gives guidelines for how future studies should comprehensively evaluate design changes. This paper includes an overview of crutch gait walking patterns, users, the components and measurements of crutch studies, and advancements of crutch designs.

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.

Accuracy of Dynamic Force Compensation Varies With Direction and Speed.

This study investigates physical responses to force perturbations while tracking a moving target. The results show accuracy depends on the direction of a force perturbation and speed of the task, but generally not on hand. There are also differences in responses when the force is first applied and when it is removed.

Comparing Gait with Multiple Physical Asymmetries Using Consolidated Metrics.

Physical changes such as leg length discrepancy, the addition of a mass at the distal end of the leg, the use of a prosthetic, and stroke frequently result in an asymmetric gait. This paper presents a metric that can potentially serve as a benchmark to categorize and differentiate between multiple asymmetric bipedal gaits. The combined gait asymmetry metric (CGAM) is based on modified Mahalanobis distances, and it utilizes the asymmetries of gait parameters obtained from motion capture and force data recorded during human walking. The gait parameters that were used in this analysis represent spatio-temporal, kinematic, and kinetic parameters. This form of a consolidated metric will help researchers identify overall gait asymmetry by showing them if the overall gait symmetry is improving and avoid the case where one parameter's symmetry is improving while another is getting worse. The CGAM metric successfully served as a measure for overall symmetry with eleven different gait parameters and successfully showed differences among gait with multiple physical asymmetries. The results showed that mass at the distal end had a larger magnitude on overall gait asymmetry compared to leg length discrepancy. It also showed that the combined effects are varied based on the cancelation effect between gait parameters. The metric was also successful in delineating the differences of prosthetic gait and able-bodied gait at three different walking velocities.

Tactile Morse Code Using Locational Stimulus Identification.

This research investigated several haptic interfaces designed to reduce mistakes in Morse code reception. Results concluded that a bimanual setup, discriminating dots/dashes by left/right location, reduced the amount of errors to only 56.6 percent of the errors compared to a unimanual setup that used temporal discrimination to distinguish dots and dashes.

Combined effects of leg length discrepancy and the addition of distal mass on gait asymmetry.

Asymmetries in gait often arise due to some form of physical impairment. For example, a leg length discrepancy (LLD) or the change of limb mass can result in asymmetric gait patterns. Although adding mass and LLD have been studied separately, this research studies how gait patterns change as a result of asymmetrically altering both leg length and mass at a leg's distal end. Spatio-temporal and kinetic gait measures are used to study the combined asymmetric effects of placing LLD and mass on the opposite and same side. There were statistically significant differences for the amount of mass and leg length added for all five parameters. Contrary to our hypothesis, there was no significant interaction between the amount of mass and leg length added. There were cases in all perturbations where a combination of mass and LLD make a gait parameter more symmetric than a single effect. These cases exhibit the potential for configurations with lower overall asymmetries even though each parameter has a slight asymmetry as opposed to driving one parameter to symmetry and other parameters to a larger asymmetry.

Quantifying the benefit of the Kinetic Crutch Tip.

This research focuses on the difference between the Kinetic Crutch Tip (KCT) and a Standard Rubber Tip. Additionally, the effect of KCT stiffness on the crutch gait cycle and the reaction forces were investigated. This study also examined the maximum backward angle that a crutch is able to move forward without any external forces as well as the ratio of positive to negative horizontal forces were considered. The results were obtained in two ways: one by having subjects walk on the crutches and another to reduce the variability of human walking by measuring the resulting motion only using weights attached to the crutch tip. The results of this measurement indicate an increase in maximum backward angle for Kinetic Crutch Tips. This increase in the rotation angle shows an improvement in forward motion of the crutch.