Changes in gait and maximum ankle torque in patients with ankle arthritis.
Findings from quantitative gait analysis and maximum ankle torque were used to assess the walking pattern of patients with ankle arthritis and to correlate the changes of gait parameters and muscle strength with severity of arthritis. Gait analysis and the isokinetic maximum ankle torque test were performed in 20 patients with first to fourth degree traumatic ankle arthritis. Six patients without evidence of traumatic arthritis were used as controls. Isokinetic maximum ankle plantarflexion and dorsiflexion torques were determined with Cybex instrumentation. Force plate and foot switch data were gathered during level walking. Maximum ankle plantarflexion and dorsiflexion torques were diminished in the injured ankles. Velocity, stride length, and cadence were decreased in arthritic patients compared with controls. The arthritic limbs had shorter single limb stance and longer double stance during free and fast walking speeds compared with the controls' affected ankles. The patterns of ground reaction forces were similar in the injured and uninvolved limbs as well as the control subjects, except the magnitude of vertical forces during push-off were reduced in arthritic ankles. The gait parameters and muscle strength deteriorated as the arthritis became severe, but they showed significant changes only when the patients had third or fourth degree arthritis.