脳卒中後の片麻痺患者の歩行時における足関節運動学および運動学と足関節筋の活性化との関係

Ankle muscle coactivation and its relationship with ankle joint kinematics and kinetics during gait in hemiplegic patients after stroke.

• Ryosuke Kitatani
• Koji Ohata
• Shuhei Sato
• Aki Watanabe
• Yu Hashiguchi
• Natsuki Yamakami
• Kaoru Sakuma
• Shigehito Yamada

抄録

はじめに:

歩行時の足関節筋の活性化を高めることは、脳卒中後の患者の姿勢安定性を向上させるための補償戦略である。しかし、これまでの研究では、脳卒中後の患者の歩行時に足関節の動きに足関節筋の活性化の増加が影響していることは示されていませんでした。

INTRODUCTION: Increased ankle muscle coactivation during gait is a compensation strategy for enhancing postural stability in patients after stroke. However, no previous studies have demonstrated that increased ankle muscle coactivation influenced ankle joint movements during gait in patients after stroke.

目的:

脳卒中後の片麻痺患者における足関節筋のcoactivationと足関節運動との関係を調べる。

PURPOSE: To investigate the relationship between ankle muscle coactivation and ankle joint movements in hemiplegic patients after stroke.

方法:

脳卒中後の患者17名が参加した。足関節のCoI（coactivation index）は，歩行中の第1，第2の二重支持（DS1，DS2）相と単支持（SS）相に分けて，表面筋電図を用いて算出した．同時に三次元運動解析を行い，足関節角度，モーメント，パワーの矢状面におけるピーク値を測定した．また、前後成分の接地反力(GRF)とCOPs(Centre of Pressure)の軌跡範囲と速度も測定した。

METHODS: Seventeen patients after stroke participated. The coactivation index (CoI) at the ankle joint was calculated separately for the first and second double support (DS1 and DS2, respectively) and single support (SS) phases on the paretic and non-paretic sides during gait using surface electromyography. Simultaneously, three-dimensional motion analysis was performed to measure the peak values of the ankle joint angle, moment, and power in the sagittal plane. Ground reaction forces (GRFs) of the anterior and posterior components and centers of pressure (COPs) trajectory ranges and velocities were also measured.

結果:

パレティック側のSS期のCoIは、パレティック側では足関節背屈角、足関節 plantarflexion moment、足関節発電量、COP速度と負の関係にあった。さらに、両側のDS2期のCoIは、両側の前部GRF振幅と負の関係にあった。

RESULTS: The CoI during the SS phase on the paretic side was negatively related to ankle dorsiflexion angle, ankle plantarflexion moment, ankle joint power generation, and COP velocity on the paretic side. Furthermore, the CoI during the DS2 phase on both sides was negatively related to anterior GRF amplitude on each side.

結論:

足関節筋の協調性を高めることは、パレティック側のSS期の足関節運動の低下と関連しており、関節剛性を高め、立脚肢不安定性を補うことができ、脳卒中後の立脚期にパレティック不安定性を有する患者に有用であると考えられる。

CONCLUSION: Increased ankle muscle coactivation is related to decreased ankle joint movement during the SS phase on the paretic side to enhance joint stiffness and compensate for stance limb instability, which may be useful for patients who have paretic instability during the stance phase after stroke.