Document Type



Recently, many types of insole in the market claim their effectiveness for improving sports performance without having clear evidence. The present study aimed to clarify how the shape of shoe insoles and the foot alignment affect the maximum muscle strength (back strength). Thirty two healthy university athletes (height: 171.7±4.54cm, mass: 70.3±5.95kg) participated in this study, and measured their 3D foot shape and back strength in 3 conditions (barefoot and two types of insole which has different structures). The back strength was significantly increased when wearing an insole with specific hind foot support (DELTA) than those of the other two conditions. Moreover, DELTA insole was found to restrict foot pronation, and add the height on foot longitudial arch.