# Hybrid neuroprosthesis with power assist for walking in SCI

> **NIH VA I01** · LOUIS STOKES CLEVELAND VA MEDICAL CENTER · 2020 · —

## Abstract

The objective of this project is to design, fabricate and evaluate a new, muscle-driven ambulatory assist
system suitable for clinical testing in the home and community environments that maximizes the functional
mobility of individuals with motor complete thoracic level spinal cord injury (SCI). Paralysis from SCI causes
rapid degeneration of almost every major organ system. Commercially available externally powered robotic
exoskeletons can begin to address such immobility in rehabilitation and supervised settings, but do nothing to
counteract the disuse atrophy of the large lower extremity muscles and ensuing cardiovascular deconditioning.
The maximal walking speeds and distances achieved with these devices fall far short of those necessary for
safe and effective ambulation in the community. As a result, veterans with SCI are still unable to access many
physical locations and life opportunities important for unrestricted reintegration into society.
 The “hybrid” approach we propose is radically different from wearable walking robots. Our “muscle first”
strategy derives the primary motive power for walking and other maneuvers by eliciting relatively short bursts
of high intensity contractions from the otherwise paralyzed muscles with electrical stimulation. Internalizing the
primary power sources means the external components only have to lock/unlock the joints or shape the
ballistic limb trajectories generated by the contracting muscles, thus eliminating the need for heavy motors at
each joint and enabling users to reap the considerable physiological benefits of exercising their lower extremity
muscles. The implanted neuromuscular component of our hybrid system is also continuously available for
spontaneous exercise and short duration standing and stepping even without donning the external component.
 Stimulated contractions of the hip, knee and ankle muscles routinely generate sufficient power to maintain
full weight bearing for several minutes, as well as to accomplish stepping motions for short distances without
the need for powered exoskeletons. However, hip flexion can be inconsistent with stimulation alone, especially
when attempting to climb steps or walk up ramps. We propose to augment stimulated contractions with a
mechanical subsystem consisting of small, lightweight and efficient brace-mounted motors located at the hips.
When powered by the contracting muscles, this novel configuration will stabilize the hips during stance, freely
rotate during swing, and provide the low-level torques required to consistently achieve the desired limb
movements in spite of variations in walking surfaces or stimulated responses. Since the motors only need to
provide the incremental torques necessary to augment the stimulated hip muscles and shape the limb
trajectories, the entire external structure can be significantly smaller, lighter, and quieter than commercially
available powered exoskeletons based on a “motor-first” strategy. Active knee extension ...

## Key facts

- **NIH application ID:** 10230983
- **Project number:** 5I01RX002275-05
- **Recipient organization:** LOUIS STOKES CLEVELAND VA MEDICAL CENTER
- **Principal Investigator:** RONALD J TRIOLO
- **Activity code:** I01 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2020
- **Award amount:** —
- **Award type:** 5
- **Project period:** 2016-10-01 → 2021-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10230983

## Citation

> US National Institutes of Health, RePORTER application 10230983, Hybrid neuroprosthesis with power assist for walking in SCI (5I01RX002275-05). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10230983. Licensed CC0.

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