Pelvic Floor Muscle Function and Endometriosis-Related Pelvic Pain

Study design: Cross-sectional study. Target population: Women of reproductive age (18-50 years) with endometriosis, as well as healthy controls.

Sampling method: Convenience sampling; participants will be recruited via online platforms and in medical outpatient clinics.

Inclusion criteria: Women aged 18-50 years in reproductive age will be included. The study group will consist of women with self-reported endometriosis, while the control group will include women who are gynecologically healthy and report no history of endometriosis. Additional inclusion criteria are adequate knowledge of the Hungarian language, access to the internet, and provision of informed consent.

Exclusion criteria: Lack of capacity to provide informed consent, severe physical or cognitive impairment, pregnancy, postpartum period, and diagnosed malignant disease.

Expected sample size: 100-140 participants. Study methodology and procedures Participants will be recruited using convenience sampling. The study consists of two parts.

The questionnaire package includes general questions (sociodemographic and anthropometric data, physical activity and exercise habits, assessment of the presence and intensity of pelvic pain, and obstetric-gynecological history), as well as several validated self-administered questionnaires.

Body mass index (BMI) will be calculated based on self-reported height and weight. Pain intensity will be assessed using the Visual Analogue Scale (VAS).

The following validated instruments are included:

VAS (Visual Analogue Scale) (Freyd, 1923) A unidimensional, 11-point scale widely used to assess subjective pain intensity ranging from 0 (no pain) to 10 (worst imaginable pain). Participants will rate their average and worst pain over the past four weeks, as well as their current pain at the time of questionnaire completion.

GPAQ (Global Physical Activity Questionnaire) (Armstrong & Bull, 2006; Ács et al., 2020) A 16-item questionnaire developed by the WHO to assess physical activity across work, transportation, and recreational domains, including sedentary behavior. Activity levels are expressed in minutes per week. Participants will be classified as physically active if they engage in at least 150 minutes of recreational physical activity per week, based on WHO recommendations (WHO, 2023).

SF-36 (Short Form Health Survey) (Ware & Sherbourne, 1992) A self-administered questionnaire measuring health-related quality of life across eight domains, including physical functioning, bodily pain, role limitations (physical and emotional), social functioning, mental health, and general health. Scores range from 0 to 100, with higher scores indicating better quality of life.

EHP-30 (Endometriosis Health Profile) (Jones et al., 2001) A disease-specific, validated questionnaire assessing the impact of endometriosis on quality of life across five domains: pain, control and powerlessness, emotional well-being, social support, and self-image. Scores range from 0 to 100, with higher scores indicating worse quality of life.

PPIQ (Pelvic Pain Impact Questionnaire) (Chalmers et al., 2017; Kovács-Szabó et al., 2025) A culturally adapted and validated Hungarian instrument assessing the impact of pelvic pain on daily life over the past month. It includes 10 items rated on a 0-4 Likert scale, with higher scores indicating greater impact.

APFQ (Australian Pelvic Floor Questionnaire) (Baessler et al., 2009; Hock et al., 2023) A 38-item questionnaire assessing bladder, bowel, prolapse, and sexual function, along with symptom-related distress. Domain scores range from 0 to 10, with a total maximum score of 40 indicating severe pelvic floor dysfunction.

Instrumental measurements Objective assessment of pelvic floor muscle function will be performed using the Myomed 932 surface EMG device.

The aim of the measurement is to determine pelvic floor muscle endurance, maximal voluntary contraction, and relaxation ability using surface electromyography and a vaginal manometric probe.