Metatarsophalangeal joint kinetics in normal walking

Foot provides body weight supports with dynamic stabilities during human walking by storing and releasing energy. Many researchers have been performed to understand the mechanism of foot during walking, assuming that the foot is a single segment; however, the human foot consists of many bones and joints. Especially, metatarsophalangeal (MP) joint, which is one of the largest joints in the foot, plays a crucial role during gait. To analyze the MP joint during normal walking ground reaction forces and foot pressure were measured simultaneously. The measured data were applied to our twosegment foot model for understanding the role of the MP joint. The maximum MP joint moment was 0.13 ± 0.04 Nm/kg at pre-swing. Compared to the previous studies, results of this study showed smooth joint moments from foot-flat the toe-off. A considerable energy absorption of approximately 6.56%GC•J/kg was found at the MP joint during 30 ~ 60% of the gait cycle. In the future study, this method will be applied for patients who have foot disease such as hallux valgus and plantar fasciitis for demonstrating mechanism of these diseases.