Walking faster and farther with a soft robotic exosuit: Implications for post-stroke gait assistance and rehabilitation

IEEE Open J Eng Med Biol. 2020:1:108-115. doi: 10.1109/ojemb.2020.2984429. Epub 2020 Apr 2.

Abstract

Objective: Soft robotic exosuits can improve the mechanics and energetics of walking after stroke. Building on this prior work, we evaluated the effects of the first prototype of a portable soft robotic exosuit.

Methods: Exosuit-induced changes in the overground walking speed, distance, and energy expenditure of individuals post-stroke were evaluated statistically with alpha set to 0.05 and compared to minimal clinically important difference scores.

Results: Compared to baseline walking without the exosuit worn, the <5kg exosuit did not substantially modify walking speed, distance, or energy expenditure when worn unpowered. In contrast, when the exosuit was powered on to provide an average 22.87±0.58 %bodyweight of plantarflexor force assistance during the paretic limb's stance phase and assist the paretic dorsiflexors during swing phase to reduce drop-foot, study participants walked a median 0.14±0.06 m/s faster during the 10-meter walk test and traveled 32±8 m farther during the six minute walk test.

Conclusions: Individuals post-stroke can leverage the paretic plantarflexor and dorsiflexor assistance provided by soft robotic exosuits to achieve clinically-meaningful increases in speed and distance.

Keywords: Exosuit; propulsion; soft robotics; stroke; walking distance; walking speed.