Measuring Pelvic Floor Muscle Fitness Before and After Treatment

Quantitative Assessment of Pelvic Floor Muscle Fitness in Myofascial Pelvic Pain Before and After Myofascially-Directed Therapies

This study is being done to better understand and improve treatment for myofascial pelvic pain, a common cause of long-lasting pelvic pain in women. Myofascial pelvic pain is related to tight or dysfunctional pelvic floor muscles and can cause pain as well as bladder, bowel, and sexual problems. Current clinical evaluations mostly rely on physical examination and patient-reported symptoms and do not fully measure how the pelvic floor muscles are functioning.

The purpose of this study is to measure pelvic floor muscle function using a noninvasive imaging method called near-infrared spectroscopy, or NIRS. This method measures changes in muscle blood flow and oxygen levels during muscle contraction and relaxation. The study will examine whether pelvic floor muscle function improves after different treatments and whether these physiologic changes are associated with improvements in pain and symptoms.

The study will enroll 120 adult women who have had pelvic pain for at least three months and have pelvic floor muscle tenderness on examination. Participants will be randomly assigned to one of three groups: education with relaxation exercises, pelvic floor physical therapy focused on myofascial release, or vaginal medication used to help relax pelvic floor muscles.

Participants will take part in four study visits over a six-month period. During these visits, they will complete questionnaires about pain and pelvic symptoms, undergo pelvic floor examinations, and have pelvic floor muscle imaging using the NIRS device while performing brief muscle contractions and relaxations. Some visits will also include collection of blood, urine, and vaginal samples to measure inflammation.

The information gained from this study may help improve the diagnosis and treatment of myofascial pelvic pain by providing objective measures of pelvic floor muscle function and identifying which treatments are most effective for different patients.

Study Overview

• Status: Not yet recruiting
• Conditions: Pelvic Pain; Chronic Pelvic Pain; Myofacial Pain; Myofascial Pelvic Pain
• Intervention / Treatment: Diagnostic test: Near Infrared Imaging

Detailed Description

STUDY OVERVIEW This is a prospective, randomized, controlled clinical study designed to objectively measure pelvic floor muscle (PFM) physiology and inflammatory changes in women with myofascial pelvic pain (MPP). The study uses a novel, transvaginal near-infrared spectroscopy (NIRS) system to assess pelvic floor muscle oxygenation, hemodynamics, and recovery during standardized contraction and relaxation tasks. The overarching goal is to improve objective diagnosis, phenotyping, and personalized treatment of MPP.

Scientific Rationale Myofascial pelvic pain is a common contributor to chronic pelvic pain in women and is characterized by pelvic floor muscle hypertonicity, impaired muscle perfusion, local acidosis, and accumulation of inflammatory mediators. These physiologic abnormalities contribute to pain as well as bladder, bowel, and sexual dysfunction. Current clinical evaluation relies largely on subjective examination and patient-reported symptoms, which limits precision in diagnosis and treatment selection.

Preliminary work has demonstrated that pelvic floor NIRS imaging can reliably distinguish women with MPP from asymptomatic controls and can identify physiologic impairments such as reduced muscle oxygenation and delayed recovery following contraction. This study evaluates whether targeted myofascial therapies improve these objective physiologic measures and whether changes in muscle physiology correlate with symptom improvement and inflammatory biomarkers.

STUDY OBJECTIVES

Primary Objective To determine whether pelvic floor muscle fitness, measured using NIRS-derived oxygenation parameters, improves following myofascial-directed treatments in women with MPP.

Secondary Objectives To characterize NIRS-derived physiologic patterns associated with symptom severity and pelvic floor dysfunction.

To assess relationships between NIRS measures and systemic and local inflammatory biomarkers.

To identify physiologic predictors of treatment response using machine-learning-based analytic approaches.

STUDY DESIGN

Design: Prospective, randomized, controlled trial

Sample size: 120 adult women with myofascial pelvic pain

Randomization: 1:1:1 allocation

Treatment arms:

Education and generalized relaxation (control) Myofascially-directed pelvic floor physical therapy Pharmacologic pelvic floor muscle relaxation

Study duration: Six months per participant

Study visits: Baseline, 1-2 weeks, 3 months, and 6 months

Total participant time: Approximately four hours across all visits

STUDY PROCEDURES

Baseline Visit After informed consent, participants complete validated questionnaires assessing pelvic pain, urinary, bowel, sexual function, psychological symptoms, and quality of life. Participants also complete two 24-hour bladder and bowel diaries.

Clinical assessments include urinalysis and post-void residual if not recently documented, standardized pelvic examination with grading of muscle strength and myofascial tenderness, perineometry, surface electromyography, and bulbospongiosus reflex testing. Pelvic floor NIRS imaging is performed transvaginally during a guided 10-minute protocol involving repeated contraction and relaxation exercises, capturing real-time oxygenated and deoxygenated hemoglobin data across multiple circumferential channels.

Biologic specimens, including blood, urine, and vaginal samples, are collected for inflammatory biomarker analysis.

Follow-Up Assessments Participants return at 1-2 weeks, 3 months, and 6 months to repeat symptom questionnaires, bladder and bowel diaries, pelvic floor examination, and NIRS imaging. Participants also complete a patient global impression of improvement assessment at all visits after treatment. Biologic specimen collection is repeated at the early post-treatment visit.

DATA MANAGEMENT AND SAFETY

All study data are collected and managed using secure, HIPAA-compliant electronic data capture systems. Data are de-identified at the time of entry. An independent monitoring process oversees recruitment, protocol adherence, and adverse events. All study procedures are considered minimal risk and consistent with standard gynecologic and pelvic floor physical therapy care.

• Study Type: Interventional
• Enrollment (Estimated): 120
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Keila S Kimura, B.S.; Phone Number: 310-825-8427; Email: kskimura@mednet.ucla.edu

Study Locations

• United States
  • California
    • Los Angeles, California, United States, 90095
      • UCLA
      • Contact: Keila S Kimura, B.S.; Phone Number: 310-825-8427; Email: kskimura@mednet.ucla.edu
      • Contact: A Lenore Ackerman, MD, PhD; Phone Number: 310-794-7700; Email: aackerman@mednet.ucla.edu
      • Principal Investigator: A Lenore Ackerman, MD, PhD
      • Sub-Investigator: Michelle Tororsis, MD
      • Sub-Investigator: Jeffery Chiang, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

Women over 18 years of age

Pelvic Pain for more than 3 months

Report an average daily pain intensity score of at least 4 on a 0 to 10 scale

Palpable trigger/tender points in internal pelvic floor muscles on standardized myofascial pelvic floor exam

Willing to refrain from new clinical treatment that may affect pain during the study period

Exclusion Criteria

Inability to participate in clinic visits

Prior invasive pelvic procedures for pain (e.g., prior pelvic surgery, sacral neuromodulation, intradetrusor Botox®) in the past 6 months

Active UTI or vaginal infection

Pregnancy or childbirth in the past 12 months, currently planning a pregnancy

Illicit Drug addiction/regular use of controlled substances (including marijuana use in the past 2 weeks or during the study period)

Pelvic floor physical therapy in the past 3 months

Malignancy or other serious medical condition (e.g., poorly controlled diabetes [HgA1c > 8], chronic renal disease [GFR <30], neurologic or rheumatic disease)

Diagnosed with an alternate cause of pelvic pain (e.g., ulcerative interstitial cystitis, vestibulodynia, vulvar dermatoses, dysmenorrhea)

Urinary retention with a PVR >150 mL

Greater than stage 3 pelvic organ prolapse

Indwelling vaginal devices (e.g., pessary, contraceptive ring. Not including Mirena IUD) that cannot be removed for the study

Inability to sign an informed consent, fill out questionnaires, or complete study interviews

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Education; Education and Generalized Relaxation. Patients are educated about myofascial pelvic pain and given a home course of non-specific relaxation exercises administered via a virtual intervention of five 5-10 min videos.	Diagnostic test: Near Infrared Imaging; Near-infrared spectroscopy (NIRS) is a noninvasive imaging technique used in this study to assess pelvic floor muscle physiology. The NIRS device uses near-infrared light to measure changes in oxygenated and deoxygenated hemoglobin within the pelvic floor muscles, providing real-time information about muscle blood flow, oxygenation, and recovery during contraction and relaxation. The device is used transvaginally during a standardized protocol that includes brief, guided pelvic floor muscle contractions and relaxations. NIRS measurements are used for assessment purposes only and are not intended for diagnosis or treatment.; Other Names: NIRS
Active Comparator: Pelvic Floor Physical Therapy; Pelvic floor physical therapy with myofascial release will be performed by a designated female physical therapist who is a Board-Certified Clinical Specialist in Women's Health Physical Therapy. The methods and approaches used will be at the discretion of the therapist, based on an individual assessment of symptoms and detailed pelvic floor assessment.	Diagnostic test: Near Infrared Imaging; Near-infrared spectroscopy (NIRS) is a noninvasive imaging technique used in this study to assess pelvic floor muscle physiology. The NIRS device uses near-infrared light to measure changes in oxygenated and deoxygenated hemoglobin within the pelvic floor muscles, providing real-time information about muscle blood flow, oxygenation, and recovery during contraction and relaxation. The device is used transvaginally during a standardized protocol that includes brief, guided pelvic floor muscle contractions and relaxations. NIRS measurements are used for assessment purposes only and are not intended for diagnosis or treatment.; Other Names: NIRS
Experimental: Pharmacological Release; Compounded intravaginal diazepam 0.5% and baclofen 0.4% ointment. Participants receive a compounded intravaginal ointment containing diazepam (0.5%) and baclofen (0.4%) to promote pelvic floor muscle relaxation. Medication is initiated nightly and may be titrated up to three times daily based on symptom response and tolerability.	Diagnostic test: Near Infrared Imaging; Near-infrared spectroscopy (NIRS) is a noninvasive imaging technique used in this study to assess pelvic floor muscle physiology. The NIRS device uses near-infrared light to measure changes in oxygenated and deoxygenated hemoglobin within the pelvic floor muscles, providing real-time information about muscle blood flow, oxygenation, and recovery during contraction and relaxation. The device is used transvaginally during a standardized protocol that includes brief, guided pelvic floor muscle contractions and relaxations. NIRS measurements are used for assessment purposes only and are not intended for diagnosis or treatment.; Other Names: NIRS

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in pelvic floor muscle oxygenation with treatment	Change from baseline in pelvic floor muscle oxygenation response to standardized contraction, measured using near-infrared spectroscopy (NIRS) after treatment interventions designed to alter pelvic floor muscle fitness	Baseline to 3 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in pelvic floor muscle recovery kinetics after pelvic floor therapies	Change from baseline in pelvic floor muscle oxygenation recovery time following contraction, measured using NIRS, with pelvic floor-directed therapies	Baseline to 3 months
Correlation of change in pelvic pain severity with NIRS metrics	Change from baseline in average pelvic pain intensity measured using a numeric rating scale (0-10) as correlated with metrics of pelvic floor muscle oxygenation	Baseline to 3 months and 6 months
Patient Global Impression of Improvement (PGI-I)	Participant-reported overall improvement in pelvic symptoms using the Patient Global Impression of Improvement (PGI-I) scale after pelvic-floor directed therapies. The PGI-I is a single-question, patient-reported scale used to measure perceived treatment response compared to a baseline, which is rated on a seven-point scale from 1 (Very much better) to 7 (Very much worse).	3 months and 6 months
Change in inflammatory biomarkers	Change from baseline in systemic and local inflammatory biomarkers measured from blood, urine, and vaginal samples after pelvic-floor directed therapies. This exploratory aim will examine a wide-range of inflammatory mediators in each biological sample, including: EGF, Eotaxin/CCL11, G-CSF, GM-CSF, IFNα2, IFNγ, IL-1α, IL-1β, IL-1RA, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8/CXCL8, IL-10, IL-12 (p40), IL-12(p70), IL-13, IL-15, IL-17A/CTLA8, IL-17E/IL-25, IL-17F, IL-18, IL-22, IP-10/CXCL10, MCP-1/CCL2, M-CSF, MIG/CXCL9, MIP-1α/CCL3, MIP-1β/CCL4, PDGF-AA, PDGF-AB/BB, RANTES/CCL5, TNFα, TNFβ/LTA, VEGF-A. While the primary analysis will examine IL-6, IL-8, and TNF-β levels before and after treatment (measure in pg/mL), as these have been implicated previously in other myofascial pain conditions, the additional biomarkers may serve to provide additional insight into disease pathophysiology.	Baseline to 1-2 weeks after therapy
Change in the Female Genitouruinary Pain Index	Change from baseline in patient-reported pelvic floor-related symptoms, including urinary, pain- and health-related quality of life will be measured using the validated female Genitourinary Pain Index (fGUPI) (scored 0-45, with higher numbers indicated worse pain and quality-of-life).	Baseline to 3 months and 6 months
Change in Colorectal Functional Outcome questionnaire (COREFO)	Change from baseline in patient-reported pelvic floor-related and bowel symptoms will be measured using the Colorectal Functional Outcome questionnaire (COREFO) (scored 0-100, where 100 indicates the worst possible bowel function)	Baseline to 3 months and 6 months
Change in International Consultation on Incontinence Questionnaire-female Lower Urinary Tract Symptoms (ICIQ-fLUTS)	Change from baseline in patient-reported pelvic floor-related and urinary symptoms, will be measured using the International Consultation on Incontinence Questionnaire-female Lower Urinary Tract Symptoms (ICIQ-fLUTS) (scored 0-48, where higher scores indicate more severe urinary symptoms )	Baseline to 3 months and 6 months
Change in Pelvic Floor Distress Index (PFDI-20)	Change from baseline in patient-reported pelvic floor-related, urinary, bowel, and pain symptoms will be measured using the validated Pelvic Floor Distress Index (PFDI-20) (scored 0-300, where higher scores indicate more severe symptoms).	Baseline to 3 months and 6 months
Change in Female Sexual Functional Index (FSFI)	Change from baseline in patient-reported sexual symptoms will be measured using validated questionnaires:Female Sexual Functional Index (FSFI) (scored 2-36, where higher scores indicate better sexual function)	Baseline to 3 months and 6 months
Change in the Hospital Anxiety and Depression Scale (HADS)	Change from baseline in patient-reported anxiety and depression symptoms will be measured using the validated Hospital Anxiety and Depression Scale (HADS) (scored 0-42, with higher scores indicating higher severity symptoms).	Baseline to 3 months and 6 months
Change in the Short Form 12 (SF-12)	Change from baseline in patient-reported health-related quality of life will be measured using the validated Short Form 12 (SF-12), which includes the Physical Component Summary (PCS) and Mental Component Summary (MCS), both weighted assessments measured such that 50 is the median score for the population, meaning that scores below 50 suggest below-average perceived health.	Baseline to 3 months and 6 months
Change in Whole Person Health Index (WPHI)	Change from baseline in patient-reported overall health, will be measured using the validated Whole Person Health Index (WPHI), which includes 9 items, each of which is measured on a 5-point Likert scale in which higher scores indicate better self-perceived health.	Baseline to 3 months and 6 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Prediction of treatment response using NIRS metrics	The Near InfraRed Spectroscopic (NIRS) pelvic floor muscle measurements are obtained vaginally during a series of pelvic floor muscle contractions, both short- and long-duration. Features abstracted from the resulting NIRS waveforms [change in oxygenated hemoglobin (measure in nM) from baseline to during MVC, the sustainable duration of SMVC (sec), and the decrease in the change in oxygenated hemoglobin with MVC over a series of contractions (measured in nM, indicative of muscle fatigue)] will be combined using generalized linear models to create a single, unitless predictive score that will be correlated with treatment responses. The magnitude of the clinical treatment response will be measured as a decrease in pain scores expressed as a continuous variable using the Numeric Rating Scale (NRS), a validated 11-point, patient-reported tool.	Baseline to 6 months

Collaborators and Investigators

• Sponsor: University of California, Los Angeles
• Collaborators: National Center for Complementary and Integrative Health (NCCIH)

Publications and helpful links

General Publications

• Bedaiwy MA, Patterson B, Mahajan S. Prevalence of myofascial chronic pelvic pain and the effectiveness of pelvic floor physical therapy. J Reprod Med. 2013 Nov-Dec;58(11-12):504-10.
• Ahangari A. Prevalence of chronic pelvic pain among women: an updated review. Pain Physician. 2014 Mar-Apr;17(2):E141-7.
• Meister MR, Sutcliffe S, Ghetti C, Chu CM, Spitznagle T, Warren DK, Lowder JL. Development of a standardized, reproducible screening examination for assessment of pelvic floor myofascial pain. Am J Obstet Gynecol. 2019 Mar;220(3):255.e1-255.e9. doi: 10.1016/j.ajog.2018.11.1106. Epub 2018 Dec 7.
• Stone RH, Abousaud M, Abousaud A, Kobak W. A Systematic Review of Intravaginal Diazepam for the Treatment of Pelvic Floor Hypertonic Disorder. J Clin Pharmacol. 2020 Dec;60 Suppl 2:S110-S120. doi: 10.1002/jcph.1775.
• Ross V, Detterman C, Hallisey A. Myofascial Pelvic Pain: An Overlooked and Treatable Cause of Chronic Pelvic Pain. J Midwifery Womens Health. 2021 Mar;66(2):148-160. doi: 10.1111/jmwh.13224. Epub 2021 Mar 31.
• Kapurubandara SC, Lowes B, Sansom-Daly UM, Deans R, Abbott JA. A systematic review of diagnostic tests to detect pelvic floor myofascial pain. Int Urogynecol J. 2022 Sep;33(9):2379-2389. doi: 10.1007/s00192-022-05258-7. Epub 2022 Jul 7.
• Deegan EG, Stothers L, Macnab AJ. Technical Development of a Transvaginal Probe Using Near Infrared Light to Monitor Pelvic Floor Muscle Hemodynamics Bilaterally. J Endourol. 2017;31(S2):A43.
• Bhambhani Y. Application of near Infrared Spectroscopy in Evaluating Cerebral and Muscle Haemodynamics during Exercise and Sport. Journal of Near Infrared Spectroscopy. 2012;20(1):117-39. doi: 10.1255/jnirs.978.

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): September 1, 2028
• Study Completion (Estimated): July 1, 2029

Study Registration Dates

• First Submitted: May 6, 2026
• First Submitted That Met QC Criteria: May 21, 2026
• First Posted (Actual): May 26, 2026

Study Record Updates

• Last Update Posted (Actual): May 26, 2026
• Last Update Submitted That Met QC Criteria: May 21, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Near-infrared spectroscopy; chronic pelvic pain; Pelvic floor physical therapy; Myofascial release therapy; pelvic floor myalgia; pelvic floor muscle dysfunction; myofascial pelvic pain; pelvic floor hypertonicity; NIRS imaging; Pelvic floor muscle oxygenation; Pelvic floor muscle blood flow; Pelvic floor muscle fitness; Pelvic floor relaxation therapy; Intravaginal diazepam; Intravaginal baclofen; Pelvic floor muscle relaxation medication; Women's pelvic pain; Noninvasive pelvic floor assessment; Pelvic floor imaging
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Pain; Neurologic Manifestations; Mental Disorders; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Genital Diseases, Female; Sexual Dysfunction, Physiological; Sexual Dysfunctions, Psychological; Vaginal Diseases; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pelvic Pain; Facial Pain; Vaginismus
• Other Study ID Numbers: 25-1502; R61AT013008-01 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified individual participant data (IPD) underlying published results will be shared with qualified researchers upon reasonable request. Data will be de-identified in accordance with applicable privacy regulations and institutional policies. Requests for data access must include a brief description of the proposed research, planned analyses, and data protection measures, and will be reviewed by the study investigators. Data will be shared through a secure data transfer mechanism following execution of an appropriate data use agreement. Data will be available beginning after publication of the primary study results and will remain available for a defined period consistent with institutional and funding agency requirements.
• IPD Sharing Time Frame: De-identified individual participant data (IPD) and supporting documents will be available beginning after publication of the primary study results. Data and supporting information will remain available for up to five years following publication, or longer as required by institutional and funding agency data-sharing policies.
• IPD Sharing Access Criteria: Access to de-identified individual participant data and supporting information will be provided to qualified researchers upon reasonable request. Researchers must submit a written proposal describing the research question, planned analyses, and data security measures. Requests will be reviewed and approved by the study investigators. Data and documents will be shared only after execution of an appropriate data use agreement and will be provided via secure electronic file transfer. Shared materials will include only de-identified data and redacted documents necessary to support the approved research purpose.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes