KNEE HYPEREXTENSION GAIT ABNORMALITIES IN UNSTABLE KNEES - RECOGNITION AND PREOPERATIVE GAIT RETRAINING

Five patients with symptomatic knee hyperextension thrusting patterns due to posterolateral ligament complex injury underwent gait analysis before and after a gait retraining program. Patients were trained to a void knee hyperextension by 1) walking with their knees slightly flexe d throughout stance, 2) maintaining ankle dorsiflexion in early stance , and 3) maintaining an erect trunk-hip attitude during stance. Kinema tic and kinetic measurements were obtained using automated gait analys is. Four of the five patients significantly reduced hyperextension at the knee and abnormal motion patterns at the hip and ankle. Patients s howed increases in knee flexion throughout stance conversions of knee flexion-extension moments to more normal biphasic patterns with a 79% decrease in extension moments at terminal extension, and a 22% decreas e in knee adduction moments. Posttraining values also showed a 30% dec rease in the calculated medial tibiofemoral loads (P < 0.05). At the h ip, there were significant decreases in abduction and adduction moment s (36% and 18%, respectively, P < 0.01). Ankle plantar flexion motion decreased significantly by 42% (P < 0.01). Gait retraining can alter t he biomechanics of hip, knee, and ankle function to approximately norm al levels, and therefore is recommended before ligament reconstruction because abnormal knee motions, if resumed postoperatively, can stretc h soft tissue reconstructions.