Influence of the menstrual cycle on static and dynamic kinematics of the foot medial longitudinal arch.

Background: In women, the laxity of the plantar fascia increases during the ovulation phase of the menstrual cycle. Although it is possible that this increased laxity results in a decreased height of the foot in the medial longitudinal arch and exacerbates symptoms of several overuse injuries of the lower extremity, the influence of the menstrual cycle on static and dynamic kinematics of the medial longitudinal arch is unclear. The purpose of this study was to confirm that the medial longitudinal arch height during static standing, gait, and landing decrease during the menstrual cycle ovulation phase.