Effect of immobilization on ankle dorsiflexion strength.

This study was performed in order to determine the loss of strength of the dorsiflexors in healthy persons after immobilization of the ankle, and the ability of these muscles to regain strength. First, isometric ankle dorsiflexion strength was measured in 33 healthy male and 39 female subjects in age categories 20-40 and 40-80 years, in order to obtain reference data and to determine the reproducibility of the measurement protocol. Gender, age and ankle position had a significant influence on the ankle dorsiflexion torque. Secondly, torque was measured in 15 patients after 4-6 weeks' immobilization of the ankle due to a fracture. A 28% decrease in dorsiflexion torque was seen. Strength reduction in neutral position and in 30 degrees plantar flexion was not significantly different. Without specific therapy restoration of torque was almost complete 6 weeks after cast removal.