The scientific literature describes several possible reasons why Pelvic Floor Muscle Training (PFMT) could contribute to the prevention of urinary incontinence. A trained muscle may be less prone to injuries or may be easier to retrain after childbirth because appropriate motor patterns have already been learned. It is possible that a previously trained muscle has a greater strength reserve, so that muscle damage or impaired innervation does not cause a sufficient loss of muscle function to reach the threshold where closure pressure of the urethra is reduced, leading to urine or fecal leakage. During pregnancy, training the perineal muscles helps counteract the increased intra-abdominal pressure caused by fetal growth, the hormone-mediated reduction in urethral closure pressure, and the increased laxity of the fascia and ligaments in the pelvic area. Based on this reasoning, the use of PFMT could prevent urinary and/or fecal incontinence. Essentially, a PFMT program can be prescribed with the following objectives:
- Increase the maximum force generated by a muscle in a single contraction.
- Increase endurance (ability to contract repeatedly or maintain a contraction for several seconds).
- Coordinate muscle activity (anticipate with precontraction of PFM before an activity that increases intra-abdominal pressure or in cases of urgency).
- Achieve one or more of the above objectives simultaneously.
Strength training is encouraged in pregnant and postpartum women. Strength training parameters include a low number of repetitions with high loads.
There are doubts about whether the intervention can be effective in women with separation of the PFM from the pelvic wall or other major defects in the PFM observed in ultrasound or magnetic resonance imaging. PFMT after childbirth could help the injury heal. However, it is also possible that PFMT may not facilitate the return of function if the muscle lacks the insertions that allow it to compress and lift the urethra with a muscular contraction.
Inés Carmona Barrientos
References:
- Dumoulin, C., Morin, M., Mayrand, M. H., Tousignant, M., & Abrahamowicz, M. (2017). Group physiotherapy compared to individual physiotherapy to treat urinary incontinence in aging women: study protocol for a randomized controlled trial. Trials, 18, 1-14.
- Bo, K., Berghmans, B., Morkved, S., & Van Kampen, M. (2014). Evidence-based physical therapy for the pelvic floor: Bridging science and clinical practice. Elsevier Health Sciences.
- Hilde G, St r-Jensen J, Siafarikas F, Ellstrom Engh M, Bø K. Effect of postpartum pelvic floor muscle training on urinary incontinence in primiparous women with and without major pelvic floor muscle defects. An assessor blinded randomised controlled trial. Neurourology and Urodynamics 2013;32(6):533–4.
