Motor Imagery of Yips-Affected Pitching Enhances Corticospinal Excitability in Baseball Players with Yips

Purpose: Yips is a psycho-neuromuscular impediment disrupting the execution of sports skills. It remains unclear how the modulation of descending motor pathway activity differs between conditions with and without yips symptoms. This is attributable to (1) the difficulty in eliciting yips in a controlled laboratory setting and (2) the technical challenges in measuring corticospinal excitability during dynamic movements. Motor imagery (MI) provides a potential approach, as it elicits neural activity patterns similar to those during actual motor execution. This study aimed to elucidate the differences in corticospinal excitability between conditions with and without yips using MI. Methods: Fifteen baseball players with yips (yips group) and 15 baseball players without yips (control group) participated. The yips group imagined their typical yips-affected pitching (yips-MI) and imagined pitching without those symptoms (no yips-MI), whereas the control group imagined making an errant throw (failed pitching-MI) and a well-controlled throw (successful pitching-MI). Motor-evoked potentials (MEPs) were recorded from the flexor carpi radialis and abductor pollicis brevis muscles using transcranial magnetic stimulation to the primary motor cortex. Results: In the yips group, MEP amplitudes were significantly increased during yips-MI and no yips-MI compared with rest, with significantly greater facilitation observed during yips-MI than no yips-MI. In the control group, MEP amplitudes were significantly increased relative to rest during both successful pitching-MI and failed pitching-MI; however, no significant difference in MEP amplitudes was found between MI conditions. Furthermore, the ratio of MEP amplitudes between MI conditions was significantly larger in the yips group than in the control group. Conclusions: These findings provide initial evidence of yips-related modulation of corticospinal excitability during MI and may inform future studies investigating the yips.