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

## TL;DR

This study shows that near-infrared spectroscopy can noninvasively detect oxygenation changes in pelvic floor muscles during rest and contraction in young women.

## Contribution

The study demonstrates NIRS as a noninvasive alternative to intracavitary methods for assessing pelvic floor muscle activity.

## Key findings

- NIRS detected significant oxygenation changes during maximum sustained voluntary contractions.
- The bulbospongiosus muscle showed higher sensitivity to NIRS measurements compared to the transverse muscle.
- NIRS can distinguish metabolic differences between rest and muscle activation on the skin surface.

## Abstract

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.

This study shows that near‐infrared spectroscopy (NIRS) is capable of identifying changes in oxygenation of the pelvic floor muscles during rest and contraction, offering a promising noninvasive alternative for clinical assessment and research in women's health.