Effects of Menstrual Cycle Phases on Gait, Pelvis, and Sleep

This cross-sectional, prospective observational study investigates the influence of menstrual cycle phases on gait spatiotemporal characteristics, pelvic kinematics, and sleep quality in healthy women aged 18-35 years with regular menstrual cycles (28 ± 7 days). Hormonal changes during the cycle may affect musculoskeletal performance, balance, and sleep quality, yet the extent of these effects on gait and pelvic motion has not been fully clarified. Participants will be evaluated in three phases of their menstrual cycle: Early follicular phase (days 1-3), determined by the onset of menstrual bleeding, Ovulation phase (days 7-9), confirmed by a salivary ovulation test, Luteal phase (days 20-23), approximately 6-8 days after ovulation. At each phase, gait spatiotemporal parameters (speed, cadence, stride length, stance and swing phases, gait cycle duration) and pelvic kinematics (tilt, obliquity, rotation symmetry) will be assessed using the BTS-G walk wireless sensor system. Sleep quality will be measured with the Pittsburgh Sleep Quality Index (PSQI).