In this study, the power assist suit which has two McKibben type pneumatic artificial muscles filled with low-pressure air on the back side of a full harness type safety belt (passive-type assist suit) was extended so that it can enhance the assist ability to lift heavy objects by providing a compressed air to the artificial muscles (active-type assist suit). In addition, the lumbar load model was derived to evaluate the assist suit for holding a heavy object with half-sitting posture. First, the labor-saving effect of the passive-type assist suit for lifting and taking down the heavy object was verified through the oxygen consumption via analysis of expired gas and muscle activity calculated from surface electromyogram. Second, improvement of the assist effect of the active-type assist suit compared with the passive-type assist suit for lifting and taking down the heavy object was verified through muscle activity. Third, decrease of the lumbar disc load by wearing the passive-type assist suit was verified through static analysis based on the derived lumbar load model and evaluation experiments of holding the heavy object with half-sitting posture.

The tactile sensation of the human foot is one of the most sensitive parts of the human skin sensation and is known to be used during various locomotion. Force-tactile presentation for the sole of the foot is considered to be effective in reproducing kinesthetic sensations. If it is possible to actually present the force sense faithfully, it is no longer necessary to learn to match the pseudo information presentation with his/her senses, so the performers have previously applied a vertical floor reaction force equivalent to that during exercise. However, there is no study about a plantar haptic display that can apply distributed ground reaction force on the four points of the sole as large as the force that human is applied during walking or running. We have developed a presentation device that applies to the bottom. In addition, we verified whether various motions can be identified only by the sole force sensation and confirmed.