Motor Imagery did not Improve Strength of Biceps Brachii

Numerous studies have confirmed that motor imagery may result in plastic change in motor system as actual physical activity. However, whether motor imagery can improve muscle strength of the trained persons remains unclear. The aim of this study is to investigate the effect of motor imagery on muscle strength. Totally 12 healthy college students were involved in 4 weeks of mental rehearsal of right upper limb movements (flexion and extension of elbow) during 30 min supervision session three times a week. Electromyogram (EMG) and peak torque of biceps brachii, reaction time of subjects were analyzed. Results showed that no significant change in EMG of biceps brachii was observed during motor imagery. After motor rehearsal for 4 weeks, statistically significant difference in EMG, peak torque and reactivity were not observed (P > 0.05) when compared with the baseline data. Therefore, motor imagery could not enhance muscle strength of subjects. Whether mental practice is a valid rehabilitation technique needs to be investigated further.