Reducing the metabolic energy of walking and running using an unpowered hip exoskeleton

Journal of NeuroEngineering and Rehabilitation

Xiaolin Huang¹  Di Hu²  Tiancheng Zhou²  Caihua Xiong²  Wenbin Chen²  Juanjuan Zhang³ 

[1] Department of Rehabilitation Medicine, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, 430074, Wuhan, Hubei, China;Institute of Rehabilitation and Medical Robotics, State Key Lab of Digital Manufacturing Equipment and Technology, Huazhong University of Science and Technology, 430074, Wuhan, Hubei, China;Institute of Robotics and Automation Information System and the Tianjin Key Laboratory of Intelligent Robotics, Nankai University, 300071, Tianjin, China;

关键词: Metabolic reduction;    Human walking and running;    Hip unpowered exoskeleton;    Hip flexion;    Human response;   

DOI  :  10.1186/s12984-021-00893-5

来源: Springer

【 摘 要 】

BackgroundWalking and running are the most common means of locomotion in human daily life. People have made advances in developing separate exoskeletons to reduce the metabolic rate of walking or running. However, the combined requirements of overcoming the fundamental biomechanical differences between the two gaits and minimizing the metabolic penalty of the exoskeleton mass make it challenging to develop an exoskeleton that can reduce the metabolic energy during both gaits. Here we show that the metabolic energy of both walking and running can be reduced by regulating the metabolic energy of hip flexion during the common energy consumption period of the two gaits using an unpowered hip exoskeleton.MethodsWe analyzed the metabolic rates, muscle activities and spatiotemporal parameters of 9 healthy subjects (mean ± s.t.d; 24.9 ± 3.7 years, 66.9 ± 8.7 kg, 1.76 ± 0.05 m) walking on a treadmill at a speed of 1.5 m s−1 and running at a speed of 2.5 m s−1 with different spring stiffnesses. After obtaining the optimal spring stiffness, we recruited the participants to walk and run with the assistance from a spring with optimal stiffness at different speeds to demonstrate the generality of the proposed approach.ResultsWe found that the common optimal exoskeleton spring stiffness for walking and running was 83 Nm Rad−1, corresponding to 7.2% ± 1.2% (mean ± s.e.m, paired t-test p < 0.01) and 6.8% ± 1.0% (p < 0.01) metabolic reductions compared to walking and running without exoskeleton. The metabolic energy within the tested speed range can be reduced with the assistance except for low-speed walking (1.0 m s−1). Participants showed different changes in muscle activities with the assistance of the proposed exoskeleton.ConclusionsThis paper first demonstrates that the metabolic cost of walking and running can be reduced using an unpowered hip exoskeleton to regulate the metabolic energy of hip flexion. The design method based on analyzing the common energy consumption characteristics between gaits may inspire future exoskeletons that assist multiple gaits. The results of different changes in muscle activities provide new insight into human response to the same assistive principle for different gaits (walking and running).

【 授权许可】

CC BY