Stroke
Conditions
Keywords
Exosuit, Neuroprosthesis, Soft Robotics, Wearable Robots, Gait Rehabilitation, Propulsion, Functional Electrical Stimulation (FES), Stroke, Neuromuscular Control
Brief summary
The objective of this study is to understand whether certain post-stroke patient subsets, identified from clinical, biomechanical, and neuromuscular characteristics, preferentially respond to different walking rehabilitation interventions that augment paretic limb propulsion (e.g., soft robotic exosuits or electrical stimulation neuroprostheses). The results of this work could improve post-stroke gait recovery outcomes by informing clinical decision-making to better match patients with rehabilitation devices tailored to their specific gait characteristics.
Detailed description
Stroke is a leading cause of long-term disability that results in slow, asymmetrical, and inefficient walking. Personalized treatments matching patients to the treatments with which they are most likely to respond are not typical but are necessary to maximize recovery. Post-stroke hemiparesis is commonly associated with reduced paretic limb propulsion that leads to slower, less efficient walking patterns. Our team has developed and tested two rehabilitation technologies targeting paretic propulsion: i) a soft robotic exosuit that uses cables to mechanically assist ankle dorsiflexion and plantarflexion during walking; ii) a neuroprosthesis that uses functional electrical stimulation (FES) to activate the dorsiflexor and plantarflexor muscles during walking. Both technologies aim to safely improve walking speed and paretic propulsion. The objective of this study is to evaluate if certain post-stroke patient subsets, identified from baseline clinical, biomechanical, and neuromuscular characteristics, preferentially respond to propulsion rehabilitation using soft robotic exosuits or electrical stimulation neuroprostheses. Twenty participants with chronic (\>6 months) stroke will complete one baseline gait evaluation in the laboratory and two gait training sessions: i) an exosuit day and ii) a neuroprosthesis day. Each visit will include walking with/without the respective technology. The primary aim of this study is to identify predictors of a therapeutic response (i.e., improvement in walking speed) to determine whether certain patient subsets preferentially respond to the exosuit or the neuroprosthesis. We will evaluate baseline clinical, biomechanical, and neuromuscular abilities as potential predictors of a response. We hypothesize that a subset of individuals will respond preferentially to each intervention and that baseline measures of gait function will predict responders to each intervention. A secondary aim of this study is to determine the rehabilitation mechanism underlying improved walking speed after walking with the propulsion exosuit and the neuroprosthesis. Improvements in walking speed can be achieved through recovery (e.g., increased propulsion symmetry) or compensation (e.g., increased nonparetic propulsion). We will independently evaluate the underlying biomechanical changes contributing to improvements in speed and metabolic cost. We hypothesize that both the exosuit and neuroprosthesis will promote improved speed via recovery of paretic propulsion.
Interventions
DEVICESoft robotic exosuit
A soft robotic exosuit is a textile-based system worn on the waist and paretic lower limb that provides assistive torques via cables connecting the front and back of the ankle to anchor points on the shank. The exosuit provides dorsiflexion assistance during swing phase for foot clearance and plantarflexion assistance during stance phase for propulsion delivered synchronously based on integrated sensors detecting the wearer's gait pattern.
A neuroprosthesis is a textile-based, surface electrical stimulation system worn on the waist and paretic lower limb that delivers stimulation assistance via electroconductive pads placed on the skin over the target muscles. The neuroprosthesis provides coordinated dorsiflexor stimulation during swing phase for foot clearance and plantarflexor stimulation during stance phase for propulsion, delivered synchronously based on integrated sensors detecting the wearer's gait pattern.
Sponsors
Harvard University
American Heart Association
National Institute for Biomedical Imaging and Bioengineering (NIBIB)
Boston University Charles River Campus
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
All participants will complete a baseline evaluation followed by two training days in a randomly assigned order. The training days are randomized between i) propulsion neuroprosthesis, ii) soft robotic exosuit.
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
* Diagnosis of a stroke event occurring at least 6 months ago * Observable gait deficits * Independent ambulation for at least 30 meters (using an assistive device as needed but without a rigid brace or ankle foot orthosis) * Passive ankle dorsiflexion range of motion to neutral with the knee extended * Ability to follow a 3-step command * Resting heart rate between 40-100 bpm * Resting blood pressure between 90/60 and 170/90 mmHg * NIH Stroke Scale Question 1b score \> 1 and Question 1c score \> 0 * HIPAA authorization to allow communication with healthcare provider * Medical clearance by a physician
Exclusion criteria
* Severe aphasia or inability to communicate with investigators * Neglect or hemianopia * Score of \>1 on question 1b and \>0 on question 1c on the NIH Stroke Scale * Serious comorbidities that may interfere with ability to participate in the research (e.g., musculoskeletal, cardiovascular, pulmonary) * Pacemakers or similar electrical implants that could be affected by the FES * Pressure ulcers or skin wounds located near human-device interface sites * More than 2 unexplained falls in the previous month * Actively receiving physical therapy for walking
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Unassisted Energy Efficiency on Treadmill (Neuroprosthesis Day) | Periprocedural (Before); Periprocedural (After) | Energy efficiency during walking on the treadmill without assistance on the training day with the propulsion neuroprosthesis at a speed determined by the average walking speed during the 6-Minute Walk Test on the Baseline Evaluation. Energy efficiency is measured using indirect calorimetry on a breath-by-breath basis and is calculated as the negative net energy cost of walking with respect to standing rest. |
| Unassisted Overground Comfortable Walking Speed (Neuroprosthesis Day) | Periprocedural (Before); Periprocedural (After) | Walking speed without assistance measured at a self-selected comfortable pace using the 10-Meter Walk Test on the training day with the propulsion neuroprosthesis. |
| Unassisted Paretic Propulsion on Treadmill (Neuroprosthesis Day) | Periprocedural (Before); Periprocedural (After) | Paretic propulsion during walking on the treadmill without assistance on the training day with the propulsion neuroprosthesis at a speed determined by the average walking speed during the 6-Minute Walk Test on the Baseline Evaluation. Paretic propulsion was calculated as the peak anterior-posterior ground reaction force of the paretic limb. |
| Unassisted Overground Fast Walking Speed (Neuroprosthesis Day) | Periprocedural (Before); Periprocedural (After) | Walking speed without assistance measured at a self-selected fast pace using the 10-Meter Walk Test on the training day with the propulsion neuroprosthesis. |
| Unassisted Overground Comfortable Walking Speed (Exosuit Day) | Periprocedural (Before); Periprocedural (After) | Walking speed without assistance measured at a self-selected comfortable pace using the 10-Meter Walk Test on the training day with the soft robotic exosuit. |
| Unassisted Overground Fast Walking Speed (Exosuit Day) | Periprocedural (Before); Periprocedural (After) | Walking speed without assistance measured at a self-selected fast pace using the 10-Meter Walk Test on the training day with the soft robotic exosuit. |
| Unassisted Paretic Propulsion on Treadmill (Exosuit Day) | Periprocedural (Before); Periprocedural (After) | Paretic propulsion during walking on the treadmill without assistance on the training day with the soft robotic exosuit at a speed determined by the average walking speed during the 6-Minute Walk Test on the Baseline Evaluation. Paretic propulsion was calculated as the peak anterior-posterior ground reaction force of the paretic limb. |
| Unassisted Energy Efficiency on Treadmill (Exosuit Day) | Periprocedural (Before); Periprocedural (After) | Energy efficiency during walking on the treadmill without assistance on the training day with the soft robotic exosuit at a speed determined by the average walking speed during the 6-Minute Walk Test on the Baseline Evaluation. Energy efficiency is measured using indirect calorimetry on a breath-by-breath basis and is calculated as the negative net energy cost of walking with respect to standing rest. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Unassisted Overground Paretic Trailing Limb Angle at Fast Speed (Neuroprosthesis Day) | Periprocedural (Before); Periprocedural (After) | Paretic trailing limb angle during walking without assistance at a self-selected fast pace during the 10-Meter Walk Test on the training day with the propulsion neuroprosthesis. Paretic trailing limb angle is the peak angle that the paretic limb makes during terminal stance phase with respect to vertical. Trailing limb angle is measured from the fifth metatarsal head to the greater trochanter with respect to vertical. |
| Unassisted Paretic Trailing Limb Angle on Treadmill (Neuroprosthesis Day) | Periprocedural (Before); Periprocedural (After) | Paretic trailing limb angle during walking on the treadmill without assistance on the training day with the propulsion neuroprosthesis at a speed determined by the average walking speed during the 6-Minute Walk Test on the Baseline Evaluation. Paretic trailing limb angle is the peak angle that the paretic limb makes during terminal stance phase with respect to vertical. Trailing limb angle is measured from the fifth metatarsal head to the greater trochanter with respect to vertical. |
| Unassisted Overground Paretic Propulsion at Fast Speed (Neuroprosthesis Day) | Periprocedural (Before); Periprocedural (After) | Paretic propulsion during walking without assistance at a self-selected fast pace during the 10-Meter Walk Test on the training day with the propulsion neuroprosthesis. Paretic propulsion was calculated as the peak anterior-posterior ground reaction force of the paretic limb. |
| Unassisted Overground Paretic Propulsion at Comfortable Speed (Exosuit Day) | Periprocedural (Before); Periprocedural (After) | Paretic propulsion during walking without assistance at a self-selected comfortable pace during the 10-Meter Walk Test on the training day with the soft robotic exosuit. Paretic propulsion was calculated as the peak anterior-posterior ground reaction force of the paretic limb. |
| Unassisted Overground Paretic Trailing Limb Angle at Comfortable Speed (Exosuit Day) | Periprocedural (Before); Periprocedural (After) | Paretic trailing limb angle during walking without assistance at a self-selected comfortable pace during the 10-Meter Walk Test on the training day with the soft robotic exosuit. Paretic trailing limb angle is the peak angle that the paretic limb makes during terminal stance phase with respect to vertical. Trailing limb angle is measured from the fifth metatarsal head to the greater trochanter with respect to vertical. |
| Unassisted Overground Paretic Propulsion at Fast Speed (Exosuit Day) | Periprocedural (Before); Periprocedural (After) | Paretic propulsion during walking without assistance at a self-selected fast pace during the 10-Meter Walk Test on the training day with the soft robotic exosuit. Paretic propulsion was calculated as the peak anterior-posterior ground reaction force of the paretic limb. |
| Unassisted Overground Paretic Trailing Limb Angle at Fast Speed (Exosuit Day) | Periprocedural (Before); Periprocedural (After) | Paretic trailing limb angle during walking without assistance at a self-selected fast pace during the 10-Meter Walk Test on the training day with the soft robotic exosuit. Paretic trailing limb angle is the peak angle that the paretic limb makes during terminal stance phase with respect to vertical. Trailing limb angle is measured from the fifth metatarsal head to the greater trochanter with respect to vertical. |
| Unassisted Paretic Trailing Limb Angle on Treadmill (Exosuit Day) | Periprocedural (Before); Periprocedural (After) | Paretic trailing limb angle during walking on the treadmill without assistance on the training day with the soft robotic exosuit at a speed determined by the average walking speed during the 6-Minute Walk Test on the Baseline Evaluation. Paretic trailing limb angle is the peak angle that the paretic limb makes during terminal stance phase with respect to vertical. Trailing limb angle is measured from the fifth metatarsal head to the greater trochanter with respect to vertical. |
| Unassisted Overground Paretic Propulsion at Comfortable Speed (Neuroprosthesis Day) | Periprocedural (Before); Periprocedural (After) | Paretic propulsion during walking without assistance at a self-selected comfortable pace during the 10-Meter Walk Test on the training day with the propulsion neuroprosthesis. Paretic propulsion was calculated as the peak anterior-posterior ground reaction force of the paretic limb. |
| Unassisted Overground Paretic Trailing Limb Angle at Comfortable Speed (Neuroprosthesis Day) | Periprocedural (Before); Periprocedural (After) | Paretic trailing limb angle during walking without assistance at a self-selected comfortable pace during the 10-Meter Walk Test on the training day with the propulsion neuroprosthesis. Paretic trailing limb angle is the peak angle that the paretic limb makes during terminal stance phase with respect to vertical. Trailing limb angle is measured from the fifth metatarsal head to the greater trochanter with respect to vertical. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Stroke Chronicity | Baseline (Day 1) | Length of time since onset of stroke. |
| Plantarflexor Central Drive | Baseline (Day 1) | Plantarflexor central drive captures the percentage of the plantarflexor muscle's total force-generating capacity that can be voluntarily controlled by an individual with a neurological injury. Central drive is calculated as the ratio of the maximum voluntary isometric contraction (MVIC) to the maximum force generating ability (MFGA). |
| Fugl-Meyer Assessment of Motor Recovery After Stroke | Baseline (Day 1) | Score on the Fugl-Meyer Assessment - Lower Extremity (FMA-LE). The FMA-LE includes a series of short activities that are assessed by a physical therapist to evaluate post-stroke recovery. |
| Six-Minute Walk Test Distance | Baseline (Day 1) | Distance walked during the Six-Minute Walk Test (6MWT), a clinical assessment measuring walking endurance. |
Countries
United States
Outcome results
None listed