触圧覚刺激を与えた母趾屈曲運動の運動イメージが脊髄神経機能の興奮性に及ぼす影響

抄録

To study the effect of motor imagery by recording the F-wave, which indicates spinal excitability, in patients with a history of falls because of decreased toe flexor strength. Thirty healthy subjects (22 men and 8 women, mean age: 22.9 ± 6.4 years) participated in this study. The F-wave was recorded with all the subjects in a resting state. The subjects were subsequently instructed to contract the left flexor hallucis brevis with maximum effort. After a 5-min rest period, they were asked to imagine the muscle contraction. F-waves were recorded at 0, 5, 10, and 15 min after completion of the motor imagery exercise. An increasing trend was observed in the persistence of the F/M amplitude ratio during imagery. Although the F/M amplitude ratio was not significantly different between the motor imagery and rest conditions, it was 3.0 ± 1.3% in the rest condition and 3.3 ± 1.4% in the motor imagery condition. The rate of F-wave appearance was not significantly different between the two conditions but showed an increasing trend in both conditions (86.4 ± 16.1% and 87.7 ± 13.4%, respectively). Application of motor imagery to contract the flexor hallucis brevis with maximum effort has potential for fall prevention as part of fall avoidance therapy.