Validation of surface EMG as a measure of intravaginal and intra-abdominal activity: implications for biofeedback-assisted Kegel exercises.

This study validates surface EMG as a measure of pelvic muscle and abdominal activity by showing its high correlation to internal pressure data. Using standardized scores, between-subjects correlation of perineal EMG and intravaginal pressure was r = .75, and the correlation of abdominal EMG and intra-abdominal pressure was r = .72. Discriminant validity was also demonstrated by showing low correlation between standardized abdominal and perineal EMG measurements (r = .10). A repeated measures multivariate analysis of variance demonstrated that visual and auditory biofeedback of EMG during pelvic floor contractions increases intravaginal pressure when compared with trials without biofeedback. Potential benefits of fabric electrodes include reduced invasiveness and risk and the ease with which patients can utilize this technology for home practice.