Design and evaluation of motion-sensing waist-assist injury-prevention clothing

Industrial work often involves repetitive load handling, sustained trunk flexion, and asymmetric postures that increase lumbar loading and injury risk, highlighting the need for practical mitigation strategies. This study developed motion-sensing waist-assist injury-prevention clothing and evaluated both assistive and sensing performance. Three configurations sharing a vest-based upper structure were designed with different lower-limb anchoring conditions: nonassisted, thigh-anchored, and ankle-anchored. Material performance was verified to ensure suitability for repeated industrial use. Task-based surface electromyography (EMG) results showed reduced erector spinae muscle (ESM) activation in assisted designs, with the ankle-anchored configuration demonstrating the most consistent and substantial reductions. Wearer evaluations indicated that anchoring interfaces were the primary source of localized discomfort. For motion sensing, a thin (<1 mm) carbon nanotube (CNT)-based textile sensor was integrated into the optimized design. During repeated flexion–extension movements at 25°, 45°, and 90°, the system achieved stable and reliable motion recognition with repeatable resistance responses. Overall, the results demonstrate the feasibility of integrating passive elastic assistance and CNT-based textile sensing into a lightweight and low-profile wearable platform for industrial applications.