観察課題と測定上肢の肢位の違いが脊髄神経機能の興奮性へ影響を与える

前腕肢位の違いにおける検討

抄録

This study investigated the changes in the excitability of spinal neural function due to differences between the upper limb position seen in an observation task and that of the measured upper limb. The excitability of spinal neural function was examined using the F wave. The subjects were 12 healthy adults with a mean age of 26.0 ± 5.4 years. The subjects sat on a chair with the right forearm in the neutral position with the palm facing left, or with the forearm supinated with the palm facing upwards. They watched two videos showing the movement of the right thumb from the radial side (radial video), and the palmar side (palmar video). The F wave was first recorded at rest, and then recorded for one minute while the subjects watched the radial video or palmar video with the right forearm in the neutral or supination positions after a four-minute rest. The F wave was elicited from the right thenar eminence following stimulation of the right median nerve. The results revealed that the relative amplitude of the F/M ratio in the forearm neutral position was significantly higher than that in the forearm supination position when the radial video was watched. In the palmar video task, although there was no significant difference between the relative persistence and the relative amplitude of the F/M ratio, it tended to show a higher value in the forearm supination position than in the forearm neutral position. These results suggest that the excitability of spinal neural function corresponding to the muscle of the right thenar eminence, increases when the upper limb position in the observation task and the position of the observer’s upper limb are similar.