The first metatarsophalangeal joint allows for extension and flexion of the great toe. Extension and flexion of the great toe can be assessed with the patient seated or in the supine position. In either position, the great toe should lie in line with the longitudinal axis of the foot. The examiner stabilizes the foot with one hand and gasps the proximal phalanx of the great toe with the other. To assess extension the examiner should move the toe cephalad (toward the patient's head). To assess flexion the examiner should move the toe caudally (away from the patient's head).
Normal passive range of motion of the first metatarsal joint is 70° of extension and 45° of felxion.
Hallux rigidus describes a first metatarsophalangeal joint with restricted range of motion. Range of motion restriction is usually a result of osteophyte accumilation in an arthritic joint. Limited range of motion at the first metatarsophalaneal joint, particularly with extension, can greatly affect normal gait.