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Completed

NCT Number: NCT06459401

Effects of an Overground Propulsion Neuroprosthesis in Community-dwelling Individuals After Stroke

This interventional study evaluates the effects of an overground propulsion neuroprosthesis that delivers adaptive neurostimulation assistance to the paretic plantarflexors and dorsiflexors of people post-stroke. Individuals with chronic post-stroke hemiparesis will walk with and without the neuroprosthesis overground and on a treadmill. The goal of the study is to understand how adaptive neurostimulation delivered by the neuroprosthesis affects clinical and biomechanical measures of walking function in order to guide future rehabilitation approaches for restoring walking ability after stroke.

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Key information

Conditions

Stroke Brain Diseases Cardiovascular Diseases Central Nervous System Diseases Cerebrovascular Disorders Nervous System Diseases Vascular Diseases

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Neuromotor Recovery Laboratory, Boston, Massachusetts, United States

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About this study

This interventional study evaluates the effects of an overground propulsion neuroprosthesis that delivers adaptive neurostimulation assistance to the paretic plantarflexors and dorsiflexors of people post-stroke. Individuals with chronic post-stroke hemiparesis will walk with and without the neuroprosthesis overground and on a treadmill. The goal of the study is to understand how adaptive neurostimulation delivered by the neuroprosthesis affects clinical and biomechanical measures of walking function in order to guide future rehabilitation approaches for restoring walking ability after stroke.

Ten individuals with chronic post-stroke hemiparesis will complete a single session of walking with and without the neuroprosthesis. Study evaluations will be conducted both before and after the session, without the neuroprosthesis active, and during the neuroprosthesis-supported walking.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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
  • 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 electrical stimulation
  • Metal implants directly under the stimulation sites
  • Pressure ulcers or skin wounds located near human-device interface sites
  • More than 2 unexplained falls in the previous month

Treatment and study plan

Propulsion Neuroprosthesis

Device

A neuroprosthesis is a textile-based surface neurostimulation system worn on the waist and paretic lower limb that delivers neurostimulation assistance via electroconductive pads placed on the skin over the target muscles. The neuroprosthesis provides 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.

Primary outcomes

  1. Immediate Change in Walking Speed

    Time frame: Early Neurostimulation Timing Condition (40% stance); Late Neurostimulation Timing Condition (60% stance)

    Change in walking speed from unassisted walking to walking with neurostimulation assistance at either an early or a late timing, measured at a self-selected fast pace across a straight 10-meter walkway. Early timing of plantarflexor neurostimulation was delivered at 40% of paretic limb support phase (before mid-stance). Late timing of plantarflexor neurostimulation was delivered at 60% of paretic limb support phase (after mid-stance).

  2. Immediate Change in Paretic Propulsion

    Time frame: Early Neurostimulation Timing Condition (40% stance); Late Neurostimulation Timing Condition (60% stance)

    Change in paretic propulsion from unassisted walking to walking with neurostimulation assistance at either an early or a late timing, measured at a self-selected fast pace across a straight 10-meter walkway. Early timing of plantarflexor neurostimulation was delivered at 40% of paretic limb support phase (before mid-stance). Late timing of plantarflexor neurostimulation was delivered at 60% of paretic limb support phase (after mid-stance). Paretic propulsion was calculated as the peak anterior-posterior ground reaction force of the paretic limb.

  3. Immediate Change in Propulsion Symmetry

    Time frame: Early Neurostimulation Timing Condition (40% stance); Late Neurostimulation Timing Condition (60% stance)

    Change in propulsion symmetry from unassisted walking to walking with neurostimulation assistance at either an early or a late timing, measured at a self-selected fast pace across a straight 10-meter walkway. Early timing of plantarflexor neurostimulation was delivered at 40% of paretic limb support phase (before mid-stance). Late timing of plantarflexor neurostimulation was delivered at 60% of paretic limb support phase (after mid-stance). Propulsion symmetry was calculated as the propulsion impulse of the paretic limb divided by the total propulsion impulse (paretic + nonparetic). Propulsion impulse is the area under the positive portion of the anterior-posterior ground reaction force curve.

  4. Immediate Change in Walking Speed

    Time frame: Early Neurostimulation Timing Condition (40% stance); Preferred Neurostimulation Timing Condition (propulsion-based tuning)

    Change in walking speed from unassisted walking to walking with neurostimulation assistance at either an early timing or an individual-specific preferred timing, measured at a self-selected fast pace across a straight 10-meter walkway. Early timing of plantarflexor neurostimulation was delivered at 40% of paretic limb support phase (before mid-stance). Timing preference was determined for each participant individually based on which of the early or late timings produced greater paretic propulsion.

  5. Immediate Change in Paretic Propulsion

    Time frame: Early Neurostimulation Timing Condition (40% stance); Preferred Neurostimulation Timing Condition (propulsion-based tuning)

    Change in paretic propulsion from unassisted walking to walking with neurostimulation assistance at either an early timing or an individual-specific preferred timing, measured at a self-selected fast pace across a straight 10-meter walkway. Early timing of plantarflexor neurostimulation was delivered at 40% of paretic limb support phase (before mid-stance). Timing preference was determined for each participant individually based on which of the early or late timings produced greater paretic propulsion. Paretic propulsion was calculated as the peak anterior-posterior ground reaction force of the paretic limb.

  6. Immediate Change in Propulsion Symmetry

    Time frame: Early Neurostimulation Timing Condition (40% stance); Preferred Neurostimulation Timing Condition (propulsion-based tuning)

    Change in propulsion symmetry from unassisted walking to walking with neurostimulation assistance at either an early timing or an individual-specific preferred timing, measured at a self-selected fast pace across a straight 10-meter walkway. Early timing of plantarflexor neurostimulation was delivered at 40% of paretic limb support phase (before mid-stance). Timing preference was determined for each participant individually based on which of the early or late timings produced greater paretic propulsion. Propulsion symmetry was calculated as the propulsion impulse of the paretic limb divided by the total propulsion impulse (paretic + nonparetic). Propulsion impulse is the area under the positive portion of the anterior-posterior ground reaction force curve.

  7. Immediate Change in Walking Speed

    Time frame: Late Neurostimulation Timing Condition (60% stance); Preferred Neurostimulation Timing Condition (propulsion-based tuning)

    Change in walking speed from unassisted walking to walking with neurostimulation assistance at either a late timing or an individual-specific preferred timing, measured at a self-selected fast pace across a straight 10-meter walkway. Late timing of plantarflexor neurostimulation was delivered at 60% of paretic limb support phase (before mid-stance). Timing preference was determined for each participant individually based on which of the early or late timings produced greater paretic propulsion.

  8. Immediate Change in Paretic Propulsion

    Time frame: Late Neurostimulation Timing Condition (60% stance); Preferred Neurostimulation Timing Condition (propulsion-based tuning)

    Change in paretic propulsion from unassisted walking to walking with neurostimulation assistance at either a late timing or an individual-specific preferred timing, measured at a self-selected fast pace across a straight 10-meter walkway. Late timing of plantarflexor neurostimulation was delivered at 60% of paretic limb support phase (after mid-stance). Timing preference was determined for each participant individually based on which of the early or late timings produced greater paretic propulsion. Paretic propulsion was calculated as the peak anterior-posterior ground reaction force of the paretic limb.

  9. Immediate Change in Propulsion Symmetry

    Time frame: Late Neurostimulation Timing Condition (60% stance); Preferred Neurostimulation Timing Condition (propulsion-based tuning)

    Change in propulsion symmetry from unassisted walking to walking with neurostimulation assistance at either a late timing or an individual-specific preferred timing, measured at a self-selected fast pace across a straight 10-meter walkway. Late timing of plantarflexor neurostimulation was delivered at 60% of paretic limb support phase (before mid-stance). Timing preference was determined for each participant individually based on which of the early or late timings produced greater paretic propulsion. Propulsion symmetry was calculated as the propulsion impulse of the paretic limb divided by the total propulsion impulse (paretic + nonparetic). Propulsion impulse is the area under the positive portion of the anterior-posterior ground reaction force curve.

  10. Immediate Change in Walking Speed

    Time frame: Non-Preferred Neurostimulation Timing Condition (propulsion-based tuning); Preferred Neurostimulation Timing Condition (propulsion-based tuning)

    Change in walking speed from unassisted walking to walking with neurostimulation assistance at either a non-preferred or a preferred timing, measured at a self-selected fast pace across a straight 10-meter walkway. Timing preference was determined for each participant individually based on which of the early or late timings produced greater paretic propulsion.

  11. Immediate Change in Paretic Propulsion

    Time frame: Non-Preferred Neurostimulation Timing Condition (propulsion-based tuning); Preferred Neurostimulation Timing Condition (propulsion-based tuning)

    Change in paretic propulsion from unassisted walking to walking with neurostimulation assistance at either a non-preferred or a preferred timing, measured at a self-selected fast pace across a straight 10-meter walkway. Timing preference was determined for each participant individually based on which of the early or late timings produced greater paretic propulsion. Paretic propulsion was calculated as the peak anterior-posterior ground reaction force of the paretic limb.

  12. Immediate Change in Propulsion Symmetry

    Time frame: Non-Preferred Neurostimulation Timing Condition (propulsion-based tuning); Preferred Neurostimulation Timing Condition (propulsion-based tuning)

    Change in propulsion symmetry from unassisted walking to walking with neurostimulation assistance at either a non-preferred or a preferred timing, measured at a self-selected fast pace across a straight 10-meter walkway. Timing preference was determined for each participant individually based on which of the early or late timings produced greater paretic propulsion. Propulsion symmetry was calculated as the propulsion impulse of the paretic limb divided by the total propulsion impulse (paretic + nonparetic). Propulsion impulse is the area under the positive portion of the anterior-posterior ground reaction force curve.

  13. Walking Speed at Non-Preferred Timing

    Time frame: Unassisted Walking Condition; Assisted Walking Condition

    Walking speed with or without neurostimulation assistance measured at a self-selected fast pace across a straight 10-meter walkway.

  14. Paretic Propulsion at Non-Preferred Timing

    Time frame: Unassisted Walking Condition; Assisted Walking Condition

    Paretic propulsion with or without neurostimulation assistance measured at a self-selected fast pace across a straight 10-meter walkway. Paretic propulsion was calculated as the peak anterior-posterior ground reaction force of the paretic limb.

  15. Propulsion Symmetry at Non-Preferred Timing

    Time frame: Unassisted Walking Condition; Assisted Walking Condition

    Propulsion symmetry with or without neurostimulation assistance measured at a self-selected fast pace across a straight 10-meter walkway. Paretic propulsion was calculated as the peak anterior-posterior ground reaction force of the paretic limb. Propulsion symmetry was calculated as the propulsion impulse of the paretic limb divided by the total propulsion impulse (paretic + nonparetic). Propulsion impulse is the area under the positive portion of the anterior-posterior ground reaction force curve.

  16. Walking Speed at Preferred Timing

    Time frame: Unassisted Walking Condition; Assisted Walking Condition

    Walking speed with or without neurostimulation assistance measured at a self-selected fast pace across a straight 10-meter walkway.

  17. Paretic Propulsion at Preferred Timing

    Time frame: Unassisted Walking Condition; Assisted Walking Condition

    Paretic propulsion with or without neurostimulation assistance measured at a self-selected fast pace across a straight 10-meter walkway. Paretic propulsion was calculated as the peak anterior-posterior ground reaction force of the paretic limb.

  18. Propulsion Symmetry at Preferred Timing

    Time frame: Unassisted Walking Condition; Assisted Walking Condition

    Propulsion symmetry with or without neurostimulation assistance measured at a self-selected fast pace across a straight 10-meter walkway. Paretic propulsion was calculated as the peak anterior-posterior ground reaction force of the paretic limb. Propulsion symmetry was calculated as the propulsion impulse of the paretic limb divided by the total propulsion impulse (paretic + nonparetic). Propulsion impulse is the area under the positive portion of the anterior-posterior ground reaction force curve.

  19. Unassisted Fast Walking Speed

    Time frame: Pre-Intervention; Post-Intervention

    Walking speed without neurostimulation assistance measured at a self-selected fast pace using the 10-Meter Walk Test.

  20. Unassisted Paretic Propulsion at Fast Speed

    Time frame: Pre-Intervention; Post-Intervention

    Paretic propulsion during walking without neurostimulation assistance at a self-selected fast pace during the 10-Meter Walk Test. Paretic propulsion was calculated as the peak anterior-posterior ground reaction force of the paretic limb.

  21. Unassisted Propulsion Symmetry at Fast Speed

    Time frame: Pre-Intervention; Post-Intervention

    Propulsion symmetry during walking without neurostimulation assistance at a self-selected fast pace during the 10-Meter Walk Test. Propulsion symmetry was calculated as the propulsion impulse of the paretic limb divided by the total propulsion impulse (paretic + nonparetic). Propulsion impulse is the area under the positive portion of the anterior-posterior ground reaction force curve.

  22. Unassisted Comfortable Walking Speed

    Time frame: Pre-Intervention; Post-Intervention

    Walking speed without neurostimulation assistance measured at a self-selected comfortable pace using the 10-Meter Walk Test.

  23. Unassisted Paretic Propulsion at Comfortable Speed

    Time frame: Pre-Intervention; Post-Intervention

    Paretic propulsion during walking without neurostimulation assistance at a self-selected comfortable pace during the 10-Meter Walk Test. Paretic propulsion was calculated as the peak anterior-posterior ground reaction force of the paretic limb.

  24. Unassisted Propulsion Symmetry at Comfortable Speed

    Time frame: Pre-Intervention; Post-Intervention

    Propulsion symmetry during walking without neurostimulation assistance at a self-selected comfortable pace during the 10-Meter Walk Test. Propulsion symmetry was calculated as the propulsion impulse of the paretic limb divided by the total propulsion impulse (paretic + nonparetic). Propulsion impulse is the area under the positive portion of the anterior-posterior ground reaction force curve.

Secondary outcomes

  1. Onset Timing of Plantarflexor Neurostimulation

    Time frame: Early Neurostimulation Timing Condition (40% stance); Late Neurostimulation Timing Condition (60% stance)

    The timepoint in the gait cycle when plantarflexor neurostimulation turns on. Early timing of plantarflexor neurostimulation was set at 40% of paretic limb support phase (before mid-stance). Late timing of plantarflexor neurostimulation was set at 60% of paretic limb support phase (after mid-stance). Actual delivery of neurostimulation may vary based on the inertial sensor based real-time control and sensing of gait features.

  2. Preferred Neurostimulation Timing

    Time frame: Preferred Neurostimulation Timing Condition (propulsion-based tuning)

    Timing preference was determined for each participant individually based on which of the early or late timings produced greater paretic propulsion. Early timing of plantarflexor neurostimulation was delivered at 40% of paretic limb support phase (before mid-stance). Late timing of plantarflexor neurostimulation was delivered at 60% of paretic limb support phase (after mid-stance).

  3. Dorsiflexion Angle (No Dorsiflexor Impairment)

    Time frame: Pre-Intervention; Non-Preferred Neurostimulation Timing Condition (propulsion-based tuning); Preferred Neurostimulation Timing Condition (propulsion-based tuning)

    Dorsiflexion angle during walking at a self-selected fast pace across a straight 10-meter walkway for the subset of participants without paretic dorsiflexor impairment. Timing preference was determined for each participant individually based on which of the early or late timings produced greater paretic propulsion. Dorsiflexion angle is the positive angle between the foot and the shank from a neutral 90-degree position, measured using optical motion capture.

  4. Dorsiflexion Angle (With Dorsiflexor Impairment)

    Time frame: Pre-Intervention; Non-Preferred Neurostimulation Timing Condition (propulsion-based tuning); Preferred Neurostimulation Timing Condition (propulsion-based tuning)

    Dorsiflexion angle during walking at a self-selected fast pace across a straight 10-meter walkway for the subset of participants with paretic dorsiflexor impairment. Timing preference was determined for each participant individually based on which of the early or late timings produced greater paretic propulsion. Dorsiflexion angle is the positive angle between the foot and the shank from a neutral 90-degree position, measured using optical motion capture. Negative dorsiflexion angle indicates plantarflexion of the foot, downwards from a neutral 90-degree position.

  5. Immediate Change in Dorsiflexion Angle

    Time frame: Non-Preferred Neurostimulation Timing Condition (propulsion-based tuning); Preferred Neurostimulation Timing Condition (propulsion-based tuning)

    Change in dorsiflexion angle from unassisted walking to walking with neurostimulation assistance at either a non-preferred or a preferred timing, measured at a self-selected fast pace across a straight 10-meter walkway. Timing preference was determined for each participant individually based on which of the early or late timings produced greater paretic propulsion. Dorsiflexion angle is the positive angle between the foot and the shank from a neutral 90-degree position, measured using optical motion capture.

  6. Immediate Change in Plantarflexor Power

    Time frame: Non-Preferred Neurostimulation Timing Condition (propulsion-based tuning); Preferred Neurostimulation Timing Condition (propulsion-based tuning)

    Change in plantarflexor power from unassisted walking to walking with neurostimulation assistance at either a non-preferred or a preferred timing, measured at a self-selected fast pace across a straight 10-meter walkway. Timing preference was determined for each participant individually based on which of the early or late timings produced greater paretic propulsion. Plantarflexor power is the peak rate of change in the rotation force of the foot towards the ground, measured using optical motion capture.

  7. Dorsiflexion Angle at Non-Preferred Timing

    Time frame: Unassisted Walking Condition; Assisted Walking Condition

    Dorsiflexion angle with or without neurostimulation assistance measured at a self-selected fast pace across a straight 10-meter walkway. Dorsiflexion angle is the positive angle between the foot and the shank from a neutral 90-degree position, measured using optical motion capture.

  8. Plantarflexor Power at Non-Preferred Timing

    Time frame: Unassisted Walking Condition; Assisted Walking Condition

    Plantarflexor power with or without neurostimulation assistance measured at a self-selected fast pace across a straight 10-meter walkway. Plantarflexor power is the peak rate of change in the rotation force of the foot towards the ground, measured using optical motion capture.

  9. Dorsiflexion Angle at Preferred Timing

    Time frame: Unassisted Walking Condition; Assisted Walking Condition

    Dorsiflexion angle with or without neurostimulation assistance measured at a self-selected fast pace across a straight 10-meter walkway. Dorsiflexion angle is the positive angle between the foot and the shank from a neutral 90-degree position, measured using optical motion capture.

  10. Plantarflexor Power at Preferred Timing

    Time frame: Unassisted Walking Condition; Assisted Walking Condition

    Plantarflexor power with or without neurostimulation assistance measured at a self-selected fast pace across a straight 10-meter walkway. Plantarflexor power is the peak rate of change in the rotation force of the foot towards the ground, measured using optical motion capture.

  11. Unassisted Dorsiflexion Angle at Fast Speed

    Time frame: Pre-Intervention; Post-Intervention

    Dorsiflexion angle during walking without neurostimulation assistance at a self-selected fast pace during the 10-Meter Walk Test. Dorsiflexion angle is the positive angle between the foot and the shank from a neutral 90-degree position, measured using optical motion capture.

  12. Unassisted Plantarflexor Power at Fast Speed

    Time frame: Pre-Intervention; Post-Intervention

    Plantarflexor power during walking without neurostimulation assistance at a self-selected fast pace during the 10-Meter Walk Test. Plantarflexor power is the peak rate of change in the rotation force of the foot towards the ground, measured using optical motion capture.

  13. Unassisted Dorsiflexion Angle at Comfortable Speed

    Time frame: Pre-Intervention; Post-Intervention

    Dorsiflexion angle during walking without neurostimulation assistance at a self-selected comfortable pace during the 10-Meter Walk Test. Dorsiflexion angle is the positive angle between the foot and the shank from a neutral 90-degree position, measured using optical motion capture.

  14. Unassisted Plantarflexor Power at Comfortable Speed

    Time frame: Pre-Intervention; Post-Intervention

    Plantarflexor power during walking without neurostimulation assistance at a self-selected comfortable pace during the 10-Meter Walk Test. Plantarflexor power is the peak rate of change in the rotation force of the foot towards the ground, measured using optical motion capture.

Sponsors and collaborators

Lead sponsor

Boston University Charles River Campus

Other

Collaborators

  • American Heart Association
  • Harvard University
  • National Institute for Biomedical Imaging and Bioengineering (NIBIB)

Registry information

Important dates

Study start
2021
Primary completion
2022
Study completion
2022
First posted
Jun 14, 2024
Registry last updated
Oct 20, 2025

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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