Journal des nouvelles physiothérapies

Abstrait

The Imagined Muscle Contraction Strengths did not affect the Changes of Spinal Motor Neurons Excitability

Yoshibumi Bunno, Chieko Onigata and Toshiaki Suzuki

Background: Motor imagery can facilitate the spinal motor neurons excitability. However, it is unclear whether the imagined muscle contraction strengths affects the changes of spinal motor neurons excitability. Methods: The F-waves of the left thenar muscles were recorded in 10 healthy volunteers while the muscle was relaxed. In motor imagery trial, subjects imagined the thenar muscles activity at maximal voluntary contractions of 10%, 30%, 50%, and 70% while holding the sensor of the pinch meter; In post-imagery trial, immediately after motor imagery, the F-waves was recorded under resting. Results: Persistence and F/M amplitude ratio during motor imagery under all imagined muscle contraction strengths were significantly increased than at rest. However, there were no significant differences in the relative values of persistence, F/M amplitude ratio, and latency under all motor imagery conditions. Conclusions: Motor imagery under maximal voluntary contractions of 10%, 30%, 50%, and 70% can increase the spinal motor neurons excitability, but excitability does not vary with the imagined muscle contraction strengths.