Normal and abnormal function of the first ray.

The first ray is the most important structure of the forefoot in its contribution to normal locomotion. Because first ray dysfunction is encountered in clinical practice with the development of hallux valgus, metatarsus primus varus, and hallux rigidus, there has been a belief that there is a mechanical basis for these conditions. Since publications in the 1930s, there has been significant research focused on the first ray. This article discusses the subtleties of normal and abnormal mechanics of the first ray to promote a better understanding for foot and ankle practitioners when treating these various disorders.