Is Pelvic Floor Muscle Resting Activity Associated with Pelvic and Genital Pain, Dyspareunia, and Pelvic Floor Muscle Contraction? A Cross-Sectional Study of Women with Endometriosis.

Introduction and hypothesis: A link between pelvic and genital pain, dyspareunia, and increased pelvic floor muscle (PFM) tone is an area of controversy. Additionally, it has been postulated that increased PFM tone can limit the ability to further activate the PFM. We aimed to investigate the association between PFM resting activity and pelvic and genital pain and dyspareunia, and whether there is an association between PFM resting activity and activation during attempts at PFM maximal voluntary contractions (MVCs) in women with endometriosis.

Methods: This cross-sectional study included 80 women with endometriosis and pelvic and genital pain. An electronic questionnaire included background information, pelvic and genital pain (numeric rating scale 0-10) and questions about location and concerns of dyspareunia. Associations between variables were analyzed using multiple linear regression. PFM resting activity was registered as the mean microvolt (μV) during rest before and between five voluntary MVCs of the PFM.

Results: Mean age was 29 years (SD 6.2), and 9 (11%) were parous. No significant association between resting activity, pelvic and genital pain or location and concerns of dyspareunia was found. A significant positive association between PFM resting activity and activation during attempts at MVCs of the PFM (β = 0.130, p = 0.009, 95% CI = 0.034-0.229) was found.

Conclusion: No association was found between PFM resting activity and pelvic and genital pain or location and concerns of dyspareunia. Contrary to the hypothesis, higher PFM resting activity resulted in more activation of the PFM during attempts at MVCs.