The mechanics of normal and hallux valgus feet--a quantitative study.

Accurate measurements of the vertical load under areas of the foot were made with a computerized instrumentation system. In a study of 148 normal feet, the normal force distribution and its variation with age was quantified. This showed the hallux to be important in sharing the load on the first ray. comparative studies of feet with hallux valgus before and after Keller's operation showed the changes that accompany reduced hallux loading. A model of the foot was used to calculate the force across the metatarsophalangeal joint and the forces and moments acting on the metatarsals.