Recently, about 60% of worker suffers from low back pain in Japan. Hard working such as lifting and carrying provides a load to waist joint, and worker gets low back pain. So, we developed a power assist suit to reduce the load of waist joint. This assist suit has various futures; endoskeleton, high output and flexibility, because this device moves using two pneumatic actuators. This device generates active and passive assistive force. These forces can assist human motions according as situations. First of all, we analyzed the human motion by motion capturing software. The analysis results are substituted into human link model, and load of human body is estimated. Thus, we decided design and operation method of the assist suit using analysis results and a static assist suit model. The motion of wearer is “lifting up motion” and “carrying motion” in evaluation experiments, because these motions are frequently performed in manufacturing plant work. Each assistive force assists these motions, and effectiveness of assist suit was confirmed from decrease of electromyography (EMG) in wearing.
