Biomechanical and Physiological Evaluation of Multi-Joint Assistance With Soft Exosuits

• Published in: IEEE transactions on neural systems and rehabilitation engineering Vol. 25; no. 2; pp. 119 - 130
• Main Authors: Ding, Ye, Galiana, Ignacio, Asbeck, Alan T., De Rossi, Stefano Marco Maria, Bae, Jaehyun, Santos, Thiago Ribeiro Teles, de Araujo, Vanessa Lara, Lee, Sangjun, Holt, Kenneth G., Walsh, Conor
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.02.2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Actuation; Actuators; Adult; Ankle; Artificial Limbs; Assistive robotics; Biomechanics; Cable shielding; Elastic Modulus; Equipment Design; Equipment Failure Analysis; Exoskeleton Device; Force; Gait; Gait - physiology; Hip; human-robot interaction; Humans; Kinematics; Leg - physiology; Legged locomotion; Metabolism; Muscles; Neurological Rehabilitation - instrumentation; Physiological effects; Plantar flexion; Reproducibility of Results; Robotics - instrumentation; Sensitivity and Specificity; soft exosuits; Surgical implants; Velocity; Walking; Walking - physiology
• ISSN: 1534-4320; 1558-0210; 1558-0210
• DOI: 10.1109/TNSRE.2016.2523250

To understand the effects of soft exosuits on human loaded walking, we developed a reconfigurable multi-joint actuation platform that can provide synchronized forces to the ankle and hip joints. Two different assistive strategies were evaluated on eight subjects walking on a treadmill at a speed of 1.25 m/s with a 23.8 kg backpack: 1) hip extension assistance and 2) multi-joint assistance (hip extension, ankle plantarflexion and hip flexion). Results show that the exosuit introduces minimum changes to kinematics and reduces biological joint moments. A reduction trend in muscular activity was observed for both conditions. On average, the exosuit reduced the metabolic cost of walking by 0.21±0.04 and 0.67±0.09 W/kg for hip extension assistance and multi-joint assistance respectively, which is equivalent to an average metabolic reduction of 4.6% and 14.6%, demonstrating that soft exosuits can effectively improve human walking efficiency during load carriage without affecting natural walking gait. Moreover, it indicates that actuating multiple joints with soft exosuits provides a significant benefit to muscular activity and metabolic cost compared to actuating single joint.