Effects of Knee-Ankle-Foot Orthosis with Knee Joint Capable of Knee Flexion Control on the Gait of Stroke Patients

Abstract

Objective：The knee joint in patients using a knee-ankle-foot orthosis (KAFO) is locked, and the lack of knee flexion can cause some problems in the gait, such as circumduction and excessive pelvic obliquity. Hence, a KAFO with knee flexion control was developed. This study aimed to compare the gait in stroke patients using KAFOs with a locked knee joint and a controlled knee joint.

Methods：A newly developed electro-attractive-material (EAM) was used for the knee joint in the KAFO. The knee joint is locked in the stance phase, and released immediately after the manual switch is pushed by a physical therapist.

The gait of seven stroke patients in the recovery phase was measured for KAFO with a locked knee joint (locked knee) and a controlled knee joint (EAM knee). For gait measurement, an inertial sensor, a foot switch, and an EMG sensor were used.

Results：The velocity increased and the swing time decreased in the EAM-knee as compared to the locked knee. The abduction, external rotation, and extension of the hip joint decreased in the EAM knee. Increased activity of the rectus femoris muscle in the loading response, and decreased activity of the longissimus doris in the swing phase were observed in the EAM knee.

Conclusions：It was suggested that EAM KAFO could improve the gait parameter and reduce the movement on the paretic side by compensatory motions in the swing phase, thereby reducing the muscle activity of the longissimus doris muscle.