The gait of a stroke patient who showed hyperextension of the knee joint in late stance was measured and compared with and without an ankle-foot orthosis. When the patient walked using an ankle-foot orthosis with an oil damper that assisted the heel rocker, the center of pressure was kept at the heel in loading response and the start of the plantar flexion moment was delayed. Forward inclination of the shank in early midstance was obtained, and the hyperextension of the knee joint in late midstance was reduced.
The orthosis was able to control the shank inclination, and the shank vertical angle was found to be an important parameter for understanding the gait of stroke patients with and without ankle-foot orthoses. Ankle-foot orthoses (AFOs) are commonly used to improve gait in stroke patients. Gait analysis of stroke patients has shown the increased velocity, cadence, and step length, improved ankle joint angle throughout the gait cycle when patients used the AFOs. In general, AFOs are used to facilitate foot clearance during swing phase, to improve the initial contact in early stance, to maintain medio lateral stability in stance.