Association Between Menstrual Pain Severity and Plantar Pressure in Young Women

Primary dysmenorrhea is a common condition characterized by recurrent menstrual pain in the absence of identifiable pelvic pathology. Menstrual pain may be accompanied by changes in posture, neuromuscular function, and postural control. These changes may influence how body weight is distributed across the feet during standing. The purpose of this observational study is to investigate the association between primary dysmenorrhea severity and plantar pressure distribution in post-pubertal females. The study will include 79 female university students aged 18-23 years with a history of primary dysmenorrhea. Participants will be recruited from the first through fourth academic years of the Faculty of Physical Therapy at Al Hayat University in Cairo, Egypt. Each participant will undergo a single assessment during the menstrual phase, specifically within the first three days of menstruation. Primary dysmenorrhea severity will be assessed using the Working Ability, Location, Intensity, Days of Pain, Dysmenorrhea (WaLIDD) scale. The scale produces a total score ranging from 0 to 12, with higher scores indicating greater severity. Plantar pressure distribution will be assessed using the DIERS pedoscan system during standardized barefoot quiet standing. The assessment will include plantar pressure distribution and anterior-posterior and right-left weight distribution. A minimum of two valid 30-second standing measurements will be obtained and averaged for analysis. The study will examine whether greater primary dysmenorrhea severity is associated with measurable differences in plantar pressure distribution and weight-bearing characteristics. No therapeutic intervention, randomization, or experimental treatment allocation will be performed.

Inclusion Criteria: * Post-pubertal females aged 18-23 years. * Regular menstrual cycles ranging from 21 to 35 days. * History consistent with primary dysmenorrhea for at least the previous six consecutive months. * Ability to stand independently without assistive devices for the duration of the pedobarographic assessment. * Provision of written informed consent before participation. Exclusion Criteria: * Diagnosis of secondary dysmenorrhea, including endometriosis, adenomyosis, pelvic inflammatory disease, or uterine fibroids, confirmed clinically or through imaging. * Current or recent pregnancy. * Neurological disorders affecting balance or sensorimotor function. * Musculoskeletal injury or condition involving the lower limbs, feet, or lumbar spine within the preceding six months. * Foot deformity or structural lower-limb abnormality known to alter plantar pressure distribution. * Current use of medications known to influence postural control, including centrally acting analgesics, benzodiazepines, or antiepileptics. * History of major lower-limb or foot surgery. * Systemic disease affecting sensory or motor function, including diabetes mellitus or peripheral neuropathy.