Non-concussive impacts, cognition, and the menstrual cycle: a proof-of-concept study of elite female footballers.

Evidence indicates females may be more susceptible to sports-related concussion with worse and prolonged symptom severity according to menstrual cycle phase. We investigated whether menstrual cycle phases influence non-concussive heading kinematics in elite female footballers, and whether these impacts affect an athlete's cognition. Five eumenorrheic elite female footballers (Mage = 23 ± 4 years) participated in a 16-week proof-of-concept study wherein menstrual cycle phases were tracked, and cognition was monitored. Participants performed a weekly controlled heading drill by heading a ball thrown from 5 m away. Head accelerations were measured using custom-moulded PROTECHT instrumented mouthguards. 256 headers revealed no significant differences in head acceleration across the various phases of the menstrual cycle. However, change in cognitive performance was related to heading completion and menstrual phase. Hormonal fluctuations during the menstrual cycle may influence cognition independent of head impact biomechanics among elite female athletes, under controlled conditions. We note that our study also demonstrated the safety and efficacy of the mouthguard equipment employed here, as well as the ease with which the protocol was received by the athletes. These outcomes should be considered when implementing future research with larger cohorts and the inclusion of match-related heading.