EEG-EMG corticomuscular coherence in bipedal balance control with visual center of pressure feedback
Tatsunori Watanabe1, Kenta Oguma2, Miku Otani3
1Graduate School of Health Sciences, Aomori University of Health and Welfare, Aomori, Japan; Faculty of Health Sciences, Aomori University of Health and Welfare, Aomori, Japan; Waseda Institute for Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan.
Objective:
Visual feedback of the center of pressure (COP) has been shown to reduce postural sway during standing tasks. This study examined the effects of visual COP feedback on corticomuscular coherence during quiet bipedal stance.
Methods:
Twenty healthy young adults with right-foot dominance stood on a force plate and were instructed to minimize body sway under three conditions: no feedback (control) and visual COP feedback at two magnifications (×1 and ×8). Electroencephalography (EEG) was recorded from Cz according to the international 10-20 system, and electromyography (EMG) was recorded bilaterally from the tibialis anterior (TA), soleus, and medial gastrocnemius muscles.
Results:
Visual COP feedback significantly reduced the root mean square (RMS) of COP in both the anteroposterior and mediolateral directions compared with the control condition. However, increasing feedback magnification did not produce further reductions in COP RMS. The mean power frequency of COP increased with both the presence and magnification of feedback. Corticomuscular coherence between EEG and the right TA significantly increased in the theta and gamma bands with feedback, but was unaffected by magnification. In addition, EMG activity of the ankle muscles increased significantly with feedback.
Conclusions:
Visual COP feedback enhances postural control during quiet bipedal stance by strengthening cortical involvement with the dominant TA and increasing ankle muscle activity.
