Prophylactic ankle stabilizers affect ankle joint kinematics during drop landings.

Abstract

Ankle joint dorsiflexion contributes to energy absorption during landing, but wearing ankle stabilizers is known to restrict passive measures of dorsiflexion. This study compared the effects of various ankle stabilizers on ankle joint kinematics during soft and stiff landings. Subjects (N = 14) performed two-legged landings off a 0.59-m platform. Kinematics of the right ankle were calculated from a sagittal plane video recording (120 Hz). Five soft and five stiff landings were performed in five ankle stabilizer conditions (no stabilizer, taping, Swede-O, AirCast, and Active Ankle), a total of 50 trials per subject. Style and stabilizer conditions were randomized across subjects. Each subject's five-trial mean value of selected kinematic variables for each landing style/stabilizer condition was entered into a two-way repeated MANOVA (alpha = 0.05). Differences between soft and stiff landing conditions were similar to those reported in the literature. Compared with the No stabilizer condition, most stabilizer conditions significantly reduced ankle dorsiflexion ROM and angular velocity during landing. The results indicate that some ankle stabilizers adversely affect ankle joint kinematics during landing.