Functional hallux rigidus and the Achilles-calcaneus-plantar system

Functional hallux rigidus is a clinical condition in which the mobility of the first metatarsophalangeal joint is normal under non-weight-bearing conditions, but its dorsiflexion is blocked when first metatarsal is made to support weight. In mechanical terms, functional hallux rigidus implies a pattern of interfacial contact through rolling, whereas in a normal joint contact by gliding is established. Patients with functional hallux rigidus should only be operated on if the pain or disability makes it necessary. Gastrocnemius release is a beneficial procedure in most patients.