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

Louis N Awad,Pawel Kudzia,Terry D Ellis,Conor J Walsh,Dheepak Arumukhom Revi

doi:10.1109/ojemb.2020.2984429

Louis N Awad, Pawel Kudzia + Show 3 more

Open Access

https://doi.org/10.1109/ojemb.2020.2984429

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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 and compared to minimal clinically important difference scores. Results: Compared to walking without the exosuit worn, the n}{}< 5 kg exosuit did not substantially modify speed, distance, or energy expenditure when worn unpowered. In contrast, when powered on to provide an average 22.87 n}{}pm 0.58 %bodyweight of paretic plantarflexor force assistance during stance phase and assist the paretic dorsiflexors during swing phase to reduce drop-foot, study participants walked a median 0.14 n}{}pm 0.06 m/s faster during the 10-meter walk test and traveled 32 n}{}pm 8 m farther during the six minute walk test (n}{}P < 0.05). 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.

Highlights

Portable robotic exoskeletons are the state of the art in wearable robotics [1]
We have studied the effects of exosuits on the mechanics and energetics of post-stroke walking, demonstrating that exosuits can actively assist the paretic limb during treadmill walking to improve ground clearance, increase propulsion symmetry, reduce gait compensations, and reduce the
Three of the six study participants approached a clinically meaningful reduction in walking distance during the first unpowered exosuit test conducted on day 1 (Fig. 1(A), Right); this penalty was not statistically significant nor was present on day 2. These findings suggest that there was some acclimation to walking with the exosuit unpowered across days and, together, indicate that an unpowered exosuit has a minimal effect on walking distance when compared to walking without an exosuit worn

Summary

Introduction

Portable robotic exoskeletons are the state of the art in wearable robotics [1]. These remarkable machines have enabled people who are unable to walk, to walk again. Exosuits use a variety of approaches to deliver assistance during walking. Our prior work leveraged the interaction of cable-based transmissions and functional textile anchors to deliver mechanical power generated by actuators worn at the waist to a user’s limbs during targeted phases of the gait cycle [9]. We have studied the effects of exosuits on the mechanics and energetics of post-stroke walking, demonstrating that exosuits can actively assist the paretic limb during treadmill walking to improve ground clearance, increase propulsion symmetry, reduce gait compensations, and reduce the

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Conclusion