Development of Pants-type Power Assisting Wear for Stand-up Motion Applying the Elastic Belts

Abstract

Elastic belts were arranged under pants to reduce the hip and knee loads during stand-up motion from chair. The elastic belts can exert assist power for hip and knee extension because the belts are elongated by forward inclining of the upper body during stand-up motion. The efficient and less interfering arrangement of the elastic belts were found that it was started from the waist, branched off at the buttocks, descended along inside and outside of the thigh, crossed at the front of the knee, descended along inside and outside of the shank, and fastened under the foot. The best branching position was at 20% of the height on the line from the patella center to the spina iliaca anterior superior. The maximum tension of the elastic belt was limited to about 160 N for males and 140 N for females by the abdominal pain. Under these conditions, the vastus load during stand-up motion was reduced by about 7%, and any interference didn't occur during sitting, walking, and going up/down stairs.