The purpose of this clinical trial is to determine if women with dysmenorrhea demonstrate an increased musculoskeletal and autonomic nervous system response to a painful visceral stimulus compared to controls. A secondary aim is to determine if interoceptive awareness moderates this relationship. The designed methodology aims to elucidate the intricate connections between the interoceptive and musculoskeletal systems in pain perception among female participants, providing valuable insights into the underlying mechanisms of interoceptive pain and functional musculoskeletal changes.

A case-control trial will be conducted. The experimental group will consist of at least 30 subjects with a pain rating during menstruation greater than or equal to 4. The control group will be age-matched participants with pain rating less than or equal to 3 during menstruation. The study will consist of one information and instrumentation session followed by one lab session. During the initial session, participants will fill out demographic information and the VAS to allow for stratification into experimental or control groups. They will be given an LH test kit and educated on how to perform LH tests. They will be asked to track their menstrual cycle on an app or online journal that can be shared with investigators. They will be asked to download an HRV app and be taught how to measure their HRV using their phone's camera. They will be instructed to take a one-minute measure of HRV once daily for 30 days beginning on the first day of their period.

On lab day, participants will be asked to remove clothing and put on a gown, booties, and disposable underwear to wear during testing. They will be led into a temperature-controlled environment where they will complete the testing. Testing includes HRV baseline measurement for 5 minutes, heartbeat counting for 3 short sessions (25, 35, and 45 seconds), and confidence about scoring. Next, an investigator with a certification to complete internal pelvic exams will ask the participant to lie on the table, and a student investigator will take the baseline measurement of their hip extension. The side being measured will be randomized, and only one side will be tested on each participant.

Next, the barostat probe will be inserted into the vaginal canal. The barostat will be inflated once to allow the participant to experience the sensation of the balloon. The probe will then be inflated until the participant reports the sensation of pain. The amount of distension in the balloon will be recorded, and hip mobility will again be measured. The purpose of this clinical trial is to determine if women with dysmenorrhea demonstrate an increased musculoskeletal and autonomic nervous system response to a painful visceral stimulus compared to controls.

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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Women are eligible for this study because it requires a vaginal canal and a uterus.

No IPD will be shared to protect confidentiality.