The influence of an ankle orthosis on the talar and calcaneal motions in chronic lateral instability of the ankle. A stereophotogrammetric analysis.

The mechanical support provided by a semirigid ankle orthosis was tested in 14 ankles with symptoms of chronic lateral instability by use of stereophotogrammetric analysis. Talar and calcaneal rotations were measured with and without the Strong ankle orthosis during manual adduction test and adduction test with a predetermined torque (5 N-m). Significant reduction of talar and calcaneal plantar flexion, internal rotation, and varus angulation was noted when the orthosis was applied. The results of this study suggest that the semirigid orthosis may provide enough external support to prevent ankle sprains and to protect ligament reconstructions.