Electromyographic evaluation of synergist muscles of the pelvic floor muscle depending on the pelvis setting in menopausal women: A prospective observational study

Abstract

Background: Pelvic floor muscle (PFM) training is recommended to increase their strength and endurance. Muscles which act synergistically with PFM are taken into consideration in the therapeutic management of weakened PFM.

Research question: how does electromyography activity of the synergists muscle to PFM change concerning pelvis position and does the greater bioelectric activity of synergist muscles affect PFM function?

Methods: A prospective, observational study evaluating the surface electromyography (sEMG) activity of selected synergist muscles of the PFM depending on the orientation of the pelvis. One hundred thirty-one menopausal women registered for the study were screened for inclusion and exclusion criteria, and by the results, eighty-two participants were enrolled for measurements. The comparisons of results between the values obtained in different positions of the pelvis (anterior pelvic tilt - P1, posterior pelvic tilt - P2 and neutral pelvic tilt - P3) were performed using Kruskal-Wallis test. A multivariate linear regression analysis was used to assess relationships between the bioelectrical activity of PFM and activity of all tested muscles - rectus abdominis (RA), gluteus maximus (GM), and adductor magnus (AM).

Results: Higher RA, GM, AM bioelectrical activity was observed in the P2 as compared to P3 (during resting and functional PFM activity)(p < 0.05). Multivariate linear regression did not find the association between the bioelectrical activity of PFM and the activity of all synergist muscles in each position.

Significance: sEMG activity of selected muscles acting synergistically with PFM differ depending on the pelvis position and is the highest in the posterior pelvic tilt. Greater activity of the synergists, resulting from the pelvic position, does not affect the myoelectric activity of PFM. It seems that muscles that act synergistically with PFM may not play such a significant role in the therapeutic management of PFM.

Keywords: Menopause; Pelvic floor muscle; Surface electromyography; Synergist muscles.