Article

It is unclear whether mental simulation without actual muscle
contraction associated with actual motion can increase the excitability of the
spinal neural function. OBJECTIVE: To determine the best method for mental
simulation without actual muscle contraction, we analyzed the
F-wave of thenar
muscles after stimulating the median nerve by motor imagery whilst holding the
sensor of a pinch meter between the thumb and index finger and without holding
the sensor. METHODS: Healthy volunteers (n = 11; mean age, 34 years) participated
in this study after providing informed consent. We examined the F-wave of the
left thenar muscles after stimulating the left median nerve at the wrist at rest
and under holding and motor imagery conditions. For the motor imagery condition,
the subjects were asked to establish 50% maximal voluntary contraction (MVC) of
isometric contraction while holding the sensor between the thumb and index finger
(motor imagery with the sensor condition) and without holding the sensor on
another day (motor imagery without the sensor condition). RESULTS: The
persistence and amplitude ratio of F/M during motor imagery with or without the
sensor was better than that during relaxation. In particular, this ratio was
significantly higher under the with sensor condition than under the without
sensor condition. CONCLUSION: Movement preparation for a motor imagery task
involving 50% MVC isometric contraction of the opponens pollicis is important.

Langue : ANGLAIS