Twenty patients with one sprained ankle and one asymptomatic ankle will be recruited. The sprained ankle of each patient will receive a standardized subtalar joint manipulation. The same patient's asymptomatic ankle will serve as the non-treatment control group. Range of motion pre- and post-manipulation will be quantified utilizing a quaternion eigen analysis. Kinematic and kinetic parameters will be collected during the manipulation to biomechanically characterize the manipulation. Pain pressure threshold and visual analog scale measurements for pain, stiffness, and quality of movement will be collected.