Effect of combined actions of hip adduction/abduction on the force generation and maintenance of pelvic floor muscles in healthy women

PLoS One. 2017 May 24;12(5):e0177575. doi: 10.1371/journal.pone.0177575. eCollection 2017.

Abstract

Pelvic floor muscle (PFM) force and coordination are related to urinary incontinence severity and to sexual satisfaction. Health professionals frequently combine classic PFM exercises with hip adduction/abduction contraction to treat these disorders, but the real benefits of this practice are still unknown. Based on a theoretical anatomy approach whereby the levator ani muscle is inserted into the obturator internus myofascia and in which force generated by hip movements should increase the contraction quality of PFMs, our aim was to investigate the effects of isometric hip adduction and abduction on PFM force generation. Twenty healthy, nulliparous women were evaluated using two strain-gauge dynamometers (one cylinder-like inside the vaginal cavity, and the other measuring hip adduction/abduction forces around both thighs) while performing three different tasks: (a) isolated PFM contraction; (b) PFM contraction combined with hip adduction (30% and 50% maximum hip force); and (c) PFM contraction combined with hip abduction (30% and 50% maximum hip force). Data were sampled at 100Hz and subtracted from the offset if existent. We calculated a gradient between the isolated PFM contraction and each hip condition (Δ Adduction and Δ Abduction) for all variables: Maximum force (N), instant of maximum-force occurrence (s), mean force in an 8-second window (N), and PFM force loss (N.s). We compared both conditions gradients in 30% and 50% by paired t-tests. All variables did not differ between hip conditions both in 30% and 50% of maximum hip force (p>.05). PFM contraction combined with isometric hip abduction did not increase vaginal force in healthy and nulliparous women compared to PFM contraction combined with isometric hip adduction. Therefore, so far, the use of hip adduction or abduction in PFM training and treatments are not justified for improving PFM strength and endurance.

MeSH terms

  • Adult
  • Cross-Sectional Studies
  • Exercise / physiology
  • Female
  • Hip / physiology
  • Humans
  • Isometric Contraction / physiology
  • Muscle Contraction / physiology*
  • Muscle Strength / physiology
  • Muscle Strength Dynamometer
  • Pelvic Floor / physiology*
  • Vagina / physiology
  • Young Adult

Grants and funding

The authors are grateful to the National Council for Scientific and Technological Development (CNPq, http://www.cnpq.br/) for funding the project (MCT/CNPq 166104/2013-2) and for ACA scholarship (478332/2013-0), to the São Paulo State Research Foundation (FAPESP, http://www.fapesp.br/en/) for also funding this project (process 2013/19610-3), and for LPC scholarship (process 2013/13820-6). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.