屈曲制御機能付き膝継手を使用した長下肢装具が脳卒中片麻痺者の歩行に及ぼす影響

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

要旨

背景：脳卒中患者に対し膝関節伸展固定の長下肢装具と膝関節のコントロールが可能な長下肢装具を装着させ，各装具の違いが歩行へ与える影響を検証することを目的とした．

方法：対象は，回復期リハビリテーション病棟入院中で歩行が見守り以上で可能な脳卒中患者7名である．方法は，膝関節伸展固定の長下肢装具と膝関節屈曲が可能な長下肢装具で10m歩行を行い，IMU慣性センサー・EMGを用い歩行計測を行った．

結果：膝関節のコントロールが可能な長下肢装具において，歩行速度，ストライド長，歩行率が有意に増加を示し，関節角度は歩行中の麻痺側股関節伸展，外転，外旋角度の最大値が有意に小さい結果となった．筋活動は上記の条件下で荷重応答期の大腿直筋が有意に増加，遊脚期の脊柱起立筋は筋活動が有意に減少した．

考察：膝関節のコントロールが可能な長下肢装具は，歩行時間距離因子を改善し，遊脚期における麻痺側の分回し動作を軽減させることを示唆した．

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.