Soft Exosuit Based on Fabric Muscle to Assist Shoulder Joint Movements in Patients With Neuromuscular Diseases

Neuromuscular diseases, such as Duchenne muscular dystrophy, can cause severe muscle weakness, compromising the ability to perform activities of daily living (ADLs). This article presents a lightweight, garment-like soft shoulder exosuit (SSE) that assists shoulder elevation using fabric-type artificial muscles woven from thin shape memory alloy springs. The SSE weighs only 440 g, operates silently, and conforms to the body of the wearer for comfortable, long-term daily use. Its seamless, garment-like design enables discreet and comfortable wear in daily life and allows the suit to be folded and stored in the same manner as regular clothing when not in use. A single actuator passively adapts to shoulder motions and generates active lift assistance through Joule heating. To evaluate its effectiveness, experiments were conducted on eight individuals with Duchenne muscular dystrophy. The active range of motion in shoulder abduction significantly improved by 57.45%, and upper limb functional performance increased by 19.37% in Performance of Upper Limb 2.0 and 13.28% in the Box and Block Test. No adverse events were reported during use. These findings demonstrate the potential of the SSE to reduce muscular effort and restore upper limb function during ADLs, supporting its applicability as a safe, wearable assistive solution for individuals with severe shoulder impairment.