The interest in the use of Near Infrared Spectroscopy (NIRS) in functional urology and in the treatment of lower urinary tract dysfunction has mentioned its potential to detect the oxygenation status and hemodynamics of various organs. To assess the function of the pelvic floor muscles (PFM), fundamental for the treatment of urogynecological disorders, measurements related to the kinetics of oxygen recovery during muscle training are still lacking.

To analyze the effectiveness of NIRS for assessing MAP.

Systematic review (PRISMA) carried out in PubMed, Virtual Health Library, Scielo, Cochrane Library, Web of Science, Scopus, PEDro, Clinical Trials and Brazilian Registry of Clinical Trials, systematically searched for studies from 2013 to 2023, combining DeCS/MeSH terms: “Near Infrared Spectroscopy and Pelvic Floor” or “Spectroscopy NIR and Pelvic Floor”. Eligibility criteria were adopted: MAP evaluation with NIRS, randomized or non-randomized controlled clinical trials, outcomes and articles in English, Portuguese, or Spanish. And exclusion criteria: overlap, case report or review, incomplete data, and use of NIRS in other muscles. The PEDro rating scale was applied.

Of nine articles, four overlapping articles were excluded, one for not applying NIRS under MAP, one for incomplete data and two reviews. Only one was included and applied to the PEDro scale (score 6). Authored by Macnab et al. (2019), aimed to develop a NIRS interface for measuring kinetic oxygen parameters (PCO) in PFM. This was a single-arm clinical study (Columbia) in a sample of 4 healthy volunteers (mean age 40 years). A transparent speculum containing the NIRS interface, and a standardized sequence of exercises was used. Data from sustained maximum voluntary contraction with analysis of the difference between Oxyhemoglobin and Deoxyhemoglobin (HbDiff) were observed. As a result, they identified a decline in HbDiff from the beginning of the contraction with restoration in recovery. Differences between right and left sides were also observed. The feasibility of monitoring PCO on the right and left sides of the PFM was evidenced. Qualitative verifications confirmed reliable data capture with minimal noise and their chromophore alteration patterns corresponded to those already observed in other voluntary muscles. There are limitations (sample size, use of speculum and unfeasibility of further statistical analyses), however, good quality data were presented with individualized and careful assessment of the muscles submitted to training regardless of the dysfunction.

NIRS has the potential for acquiring information not previously accessible, but it is not yet ready for clinical practice, requiring further studies to explore its potential in providing PCO, currently not available through other means.

In PFM training, we lack standardized methodologies to quantify strength and resistance measurements, which is a challenge for clinical treatment planning. Obtaining PCO, through NIRS technology, can improve the understanding of PFM dysfunctions and respond to the call for techniques that improve care.