A soft robotic exosuit improves walking in patients after stroke

Area of Science:

• Biomedical Engineering
• Rehabilitation Robotics
• Neurorehabilitation

Background:

• Stroke frequently causes hemiparetic gait, characterized by slow, metabolically costly walking.
• Ankle-foot orthoses offer limited benefits, with walking often remaining impaired.
• Soft wearable robots (exosuits) present a novel approach to assist paretic limb function.

Purpose of the Study:

• To evaluate the immediate effects of an exosuit on gait parameters in individuals with chronic stroke.
• To determine if exosuit assistance can improve paretic limb propulsion and ankle function.
• To assess the impact of exosuit use on the metabolic cost and asymmetry of post-stroke walking.

Main Methods:

• A controlled, treadmill-based biomechanical investigation was conducted.
• Participants in the chronic phase of stroke recovery used a soft exosuit.
• Gait parameters, including ankle dorsiflexion, forward propulsion, interlimb asymmetry, and metabolic cost, were measured.

Main Results:

• The exosuit significantly increased paretic ankle swing phase dorsiflexion by 5.33 ± 0.91°.
• Exosuit assistance led to an 11 ± 3% increase in paretic limb forward propulsion.
• Walking's energy cost decreased by 10 ± 3%, equivalent to a 32 ± 9% reduction in metabolic burden, with a 20 ± 4% reduction in interlimb asymmetry.

Conclusions:

• A lightweight, nonrestrictive exosuit can facilitate more normal walking in individuals with stroke.
• Even low levels of assistance (~12% of biological torques) are sufficient to improve gait.
• Exosuit technology holds potential for improving post-stroke mobility and independence.