2021 Volume 49 Issue 3 Pages 119-123
This study aimed to investigate the change in the excitability of anterior horn cells of the spinal cord by evaluating the differences between the F waves using various observation targets for healthy subjects. The F wave was elicited from the right abductor digiti minimi (ADM). In the protocol, the F wave was first recorded at rest, and then recorded for one minute while the subject watched a video after a four-minute rest period. The video was showed three tasks of the right hand: a video showing movement of the little finger (task A); a video showing movements of little finger, ring finger, middle finger and index finger simultaneously (task B); and a video same as B but blurring the hand except the little finger (task C). The F/M amplitude ratio was investigated for the three tasks. As results the relative F/M amplitude ratio was significantly higher in tasks A and C than in task B. These results suggest that the excitability of the anterior horn cells innervating ADM was increased by visual attention directed to the movement of the little finger.
