Objective Changes in Pelvic Floor Muscle Strength and Length in Women With High-Tone Pelvic Floor Dysfunction After Pelvic Floor Physical Therapy (RELAX Trial)

Abstract

Although pelvic floor physical therapy (PFPT) is effective in treating high-tone pelvic floor dysfunction (HTPFD), data on the mechanism of improvement are limited. This study aimed to compare squeeze intravaginal closure force after 6 weeks of PFPT in women affected by HTPFD and, secondarily, to describe changes in levator dimensions and short-term effects of PFPT on bladder, bowel, and pain symptoms. We conducted a prospective cohort study of patients undergoing 6 sessions of PFPT for the diagnosis of HTPFD. At baseline, we measured intravaginal closure force using an instrumented speculum, levator hiatal dimension using a 3-dimensional endovaginal ultrasonography, and symptom severity using 3 validated questionnaires. Intravaginal closure force and symptoms were reevaluated after the second, fourth, and sixth PFPT sessions, and levator hiatus was reevaluated at the sixth session. Twenty-six women were enrolled and 22 completed 6 sessions and are included in the analysis. Contrary to our hypothesis, mean ± SD vaginal closure force (N) did not demonstrate a significant change (3.27 ± 2.34 vs 3.67 ± 2.02 N, P = 0.18). However, mean levator hiatal area (cm2) increased between visit 1 (13.71 ± 1.77 cm2) and visit 6 (14.43 ± 2.17 cm2, P = 0.05), as did the transverse diameter (3.83 ± 0.03 vs 3.95 ± 0.03 cm, P = 0.04). Survey responses demonstrated significant improvements across all measures of genitourinary symptoms, pain, lower gastrointestinal symptoms and quality-of-life measures after 6 sessions of PFPT. Although the levator hiatal area increased after 6 sessions of PFPT (suggesting muscle lengthening), we were unable to demonstrate that this changed the force generated by pelvic floor muscles as measured by a speculum.