Gait analysis after successful mobile bearing total ankle replacement.

Background: The effect of total ankle replacement on gait is not fully known in terms of joint kinematics, ground reaction force, and activity of the muscles of the lower leg. Methods: A comparative gait study was done in 10 patients after uneventful unilateral mobile-bearing total ankle replacement and 10 healthy controls. A rigid body model was used to describe the motion of the knee and the three-dimensional motion of the ankle-hindfoot complex during barefoot walking. An opto-electronic motion analysis system was used to analyze bilateral movement patterns, synchronized with recordings of the ipsilateral vertical ground reaction forces and the electromyographic activity of four lower leg muscles. Results: Velocity was 6% lower in the patient group. Dorsiflexion in the operated ankles was reduced (p < 0.001). No differences were found in the joint angular pattern of the knee joint and only minimal changes were found at the hindfoot-to-tibia and forefoot-to-hindfoot levels. The ground reaction force at ...