The effect of instructional and motivational self-talk on accuracy and electromyography of active and passive muscles in elbow joint position sense test

The benefits of self-talk on motor performance are well documented. However, there is a gap in the literature on basic research into the mechanisms underlying the performance outcomes of self-talk. The purpose of this study was to determine the neuromuscular mechanisms underlying the effects of instructional and motivational self-talk. Fifteen young females participated in a within-subject counterbalanced design under control, instructional, and motivational self-talk conditions. Surface electromyography (sEMG) was recorded from active (the right biceps and triceps brachii) and passive (the frontalis and left biceps brachii) muscles during reproduction of the elbow flexion angle (90 degrees) in the joint position sense test. The self-talk conditions led to a significantly lower EMG activity of the right biceps muscle, decreased co-contraction ratio of right biceps activity to right triceps activity, and reduced absolute error for the elbow joint position sense compared to the control condition. Also, EMG gradients in the passive muscles were observed in the self-talk conditions but not in the control condition. These findings suggest that attention and motivation are the mechanisms that justify the relationship between self-talk and performance.