How pelvic organ pain affects muscles and the automatic nervous system in women with painful periods

The Effect of Vaginal Somatovisceral Pain on Hip Extension Mobility and Strength in Women at Mid-cycle With Dysmenorrhea vs. Controls: A Case-control Study

Not applicable Interventional Azusa Pacific University · NCT07209566

We will test whether women with painful periods show bigger muscle and automatic nervous system (heart-rate variability) responses to a brief pelvic pain stimulus than women without painful periods.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment60 (estimated)
Ages18 Years to 35 Years
SexFemale
SponsorAzusa Pacific University Academic / other
Locations1 site (Azusa, California)
Trial IDNCT07209566 on ClinicalTrials.gov

What this trial studies

This case-control study will compare women with moderate-to-severe dysmenorrhea (≥4/10 menstrual pain) to age-matched controls (≤3/10) using a standardized brief visceral pain stimulus. Participants complete an initial information and instrumentation visit, record daily one-minute HRV measurements via a phone app for 30 days, and then attend a single lab session where baseline HRV, heartbeat counting tasks, and confidence ratings are recorded. In the lab a certified investigator administers a controlled internal pelvic stimulus while musculoskeletal and autonomic responses are measured. The study also measures interoceptive awareness to see if it changes the relationship between visceral pain and musculoskeletal/autonomic responses.

Who should consider this trial

Good fit: Women aged 18–36 who are non-pregnant, not using hormonal birth control, have regular 28–35 day cycles, and report either menstrual pain ≥4/10 (cases) or ≤3/10 (controls) are ideal candidates.

Not a fit: People who are pregnant, breastfeeding, recently postpartum, undergoing IVF, have recent abdominal/pelvic surgery, chronic pain or diagnosed pelvic conditions (e.g., endometriosis, interstitial cystitis, IBS), abnormal cycle length, a history of sexual assault, incontinence, or other listed exclusions are unlikely to be eligible or to benefit from participation.

Why it matters

Potential benefit: If successful, this work could identify measurable links between pelvic-organ pain, muscle function, and autonomic responses that help guide better diagnosis and targeted treatments for painful periods.

How similar studies have performed: Previous research has linked autonomic measures like HRV to visceral pain, but combining internal pelvic provocation with musculoskeletal measures in dysmenorrhea is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria: Non-pregnant women, not taking hormonal birth control, between the ages of 18 and 36 who report regular menstrual cycles are eligible for the study Exclusion Criteria: Participants will be excluded if they are currently pregnant or, have given birth within the preceding six months, are breastfeeding, or are undergoing in-vitro fertilization treatments. Exclusions also include those who have had abdominal, lumbar, or pelvic surgery within the preceding 12 months, suffer from a chronic pain condition, have an active genitourinary infection, are incontinent of bowel or bladder, or have been diagnosed with prolapse of a pelvic organ, severe labral pathology, femoral acetabular impingement (FAI), interstitial cystitis, endometriosis, pelvic inflammatory disease, irritable bowel syndrome, or other pelvic pathology. Participants reporting a cycle length of less than 28 days or longer than 35 days, those with a history of sexual assault, and those who are anovulatory without hormonal BC or amenorrheic will also be excluded.

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Where this trial is running

Azusa, California

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions DysmenorrheaDysmenorrhea PrimaryVisceral PainMenstrual PainEffect of visceral organ pain on musculoskeletal and autonomic nervous system
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.