To Abduct or Adduct Hips: Does the Pelvic Floor Care?

When reading published research on a subject matter directly relating to what we do in our career, we may need to remember the expression, “Don’t throw the baby out with the bathwater.” Sometimes the test results for a promising hypothesis are not statistically significant, and we can close our minds to the concept entirely. If we skim the abstract and hone in on the “results” or “conclusion” rather than reading the whole article, particularly a study’s limitations, we may drop a sound clinical pearl down the drain.

A research article published in May 2017 by Amorim et al., looked at the force generation and maintenance of the pelvic floor muscles when combined with hip adduction or abduction contractions. They hypothesized that pelvic floor muscle (PFM) contraction combined with hip abduction contraction (rather than adduction) should produce a greater PFM contraction because of the myofascial connection of the obturator internus to the levator ani muscle. The study included 20 nulliparous women without pelvic floor dysfunction. The pelvic floor muscle contraction was measured in isolation, with 30% and 50% maximum hip adduction contraction, and with 30% and 50% maximum hip abduction contraction. The forces were measured with a cylindrical, intravaginal strain-gauge for PFM and another strain-gauge around the hips for adduction/abduction force generation. The women were given visual feedback to help them obtain the required hip contraction force. An average of 3 contractions (10 seconds each with a 1 minute rest) was used for each condition. This was all performed again 4 weeks later.

The results of this study by Amorim et al.²⁰¹⁷ did not support the hypothesis. No statistically significant difference was found among any of the conditions measured. The intravaginal PFM force generation was not different when combined with hip abduction versus hip adduction contraction. Neither hip adduction nor abduction made a significant change in force of the PFM contraction compared to isolated PFM contraction. The authors had to conclude there is no evidence to support the efficacy of combining PFM training with contraction of the hip abductors or adductors.

Even Amorim et al., admitted the study had limitations, and the benefit of PFM training combined with the hip contractions could exist under more “chronic” conditions rather than the brief testing period used in the research. They also used healthy women who had no children, which could make for a different outcome than if they used women with pelvic dysfunction. The specificity of the strain-gauges and the feedback given was not flawless. The authors encouraged further study on the subject. Perhaps there could be an important correlation between PFM and hip abduction contraction not yet found.

Reading research is an integral part of being a responsible healthcare professional, but without solid discernment, we could be entranced or blinded by bubbles as the “baby” escapes us. Taking a course (online or in person) that enhances overall understanding of a subject matter such as the correlation between the lumbopelvic region and the hip can equip the practitioner with a broader foundation upon which clinical decisions can be made. Recognize what concepts to keep and which to wash away, and realize one patient may benefit from what a randomized controlled trial could not cleanly prove to work.

Amorim, A. C., Cacciari, L. P., Passaro, A. C., Silveira, S. R. B., Amorim, C. F., Loss, J. F., & Sacco, I. C. N. (2017). Effect of combined actions of hip adduction/abduction on the force generation and maintenance of pelvic floor muscles in healthy women. PLoS ONE, 12(5), e0177575. http://doi.org/10.1371/journal.pone.0177575