Near-Infrared Spectroscopy as a Resource for Assessing the Rest and Activation of Pelvic Floor Muscles in Young Adult Women: A Cross-Sectional Study.

This study evaluated the potential of near-infrared spectroscopy (NIRS) as a noninvasive tool to assess pelvic floor muscle oxygenation in young adult women. Thirty-eight participants were divided into a control group (rest) and an activation group (phasic and sustained contractions). Measurements were obtained with the Humon Hex device placed on the skin overlying the bulbospongiosus and superficial transverse muscles. Muscle activation, especially during maximum sustained voluntary contraction, resulted in significant oxygenation changes, with greater variability in the activation group. The bulbospongiosus showed higher sensitivity, whereas the transverse muscle presented more stable responses. Despite limitations related to sensor adaptation and signal stability, NIRS detected differences in metabolic demands between rest and activation when placed on the skin surface. These findings support NIRS as a potential and comfortable alternative to transvaginal intracavitary techniques, contributing to objective evaluation, prevention, and rehabilitation strategies in women's pelvic health.