Abstract
Recently, an emphasis has been placed on understanding how ovarian sex hormones and
hormonal contraceptives affect risk for anterior cruciate ligament (ACL) injury. The
literature presents large discrepancies in whether or not hormonal contraceptives
affect ACL injury risk; therefore, the purpose of this study was to evaluate whether
vertical ground reaction force (GRF) and knee valgus force are different between athletes
who do and do not use hormonal contraceptives. Twenty-two female athletes volunteered
to participate and were divided into two groups based on their answers to a health
history questionnaire: those who use hormonal contraceptives and those who do not.
Participants performed a drop vertical jump (DVJ) and single leg crossover dropdown
(SCD) at two different time points in their menstrual cycle (pre-ovulatory phase and
mid-luteal phase). Kinetic data were collected at 1000 Hz. Independent samples t-tests
revealed no significant differences between groups in vertical GRF and knee valgus
force at both time points. Findings from this study suggest that hormonal contraceptives
do not elicit detectable changes in vertical GRF and knee valgus force. Ultimately,
this calls for further studies on the relationship between hormones and ACL injury
risk and physicians to consider hormonal screening in addition to neuromuscular and
biomechanical screening.
Key words
anterior cruciate ligament - hormonal screening - injury prevention