ABSTRACT

　The purpose of this study was to quantify changes in the foot medial longitudinal arch and the plantar load distribution during running. Plantar pressure measurement plate （Novel GmbH?, 100Hz） , motion capture system （Oxford, 100Hz） and Force plate （Kistler, 1KHz） were synchronized. Plantar load distribution was divided into five sub-area based on anatomical measurement points. Medial longitudinal arch angle was calculated as the angle between the first metatarsal distal medial, navicular tuberosity and posterior aspect of heel, and first metatarsophalangeal joint angle as the angle between the hallux proximal end of first phalanx, first metatarsal distal and proximal medial. The plantar load was observed to shift to the forefoot during push off, and the medial longitudinal arch angle showed the largest change. Thereafter, the anterior ground reaction force tended to increase with dorsiflexion of the metatarsophalangeal joint. Medial longitudinal arch is a flexible structure that absorbs plantar load during foot contact, and it was assumed that the dorsiflexion of the first metatarsophalangeal joint during push off contributed to the increase in foot stiffness to support forward propulsion from the forefoot.

DECENTE SPORTS SCIENCE Vol.44/The DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE