Effectiveness of a knee-ankle-foot orthosis with a knee extension aid in gait training for stroke patients.

Abstract

To evaluate the effectiveness of a knee-ankle-foot orthosis (KAFO) with a newly developed knee extension aid in gait training for stroke patients with severe leg paralysis. The participants were 7 recovering stroke patients prescribed a KAFO. With the KAFO knee joint set to allow free flexion, knee flexion angle, lower limb muscle activity, and time of plantar ground contact were measured during assisted walking with the knee extension aid or a conventional support loop. When first using the knee extension aid, knee flexion angle at initial ground contact was significantly decreased and time from heel strike on the paralyzed side to forefoot strike was prolonged compared with the support loop. After using the knee extension aid for 1 week, in addition to the two parameters above, maximum knee flexion angle during the swing phase, knee extension displacement from the maximum flexion angle to initial ground contact, and the muscle activity ratio of the biceps femoris during the swing phase were significantly increased compared with the support loop. This knee extension aid may be indicated for patients who have difficulty in initial heel strike due to excessive knee flexion at the end of the swing phase.