Introduction The US Marine Corps (USMC) Officer Candidates School (OCS) is a 10-week training course for Marine Officer Candidates (MOCs). OCS training is rigorous and demanding, which results in a high risk of musculoskeletal injuries (MSIs). The objective of this analysis was to describe MSIs among women and men during the USMC OCS at Quantico, Virginia, from September 2020 to November 2021.

Methods This prospective cohort study assessed MSIs that occurred among 736 MOCs (women: 17.8% of sample, men: 82.2%). Data for the study were derived from routinely collected injury data by athletic trainers and physical therapists embedded within the training units. Injury incidence, event at the time of injury occurrence, anatomic location, injury type and disposition following injury were described. Fisher’s exact tests were used to compare proportions of injured women and men.

Results The cumulative injury incidence was higher among women (39.7%) compared with men (23.1%, p<0.001). When specific events associated with injuries were reported, most frequent events were the obstacle course (women: 20.9% of injuries, men: 12.9%) and the conditioning hike (women: 11.6%, men: 6.9%). Most injures affected the lower body (women: 67.4%, men: 70.8%). The most frequent body part injured was the lower leg (18.6%) in women and the knee (23.3%) in men. The most frequent injury type was strain (women: 39.5%, men: 24.3%), followed by sprain (women: 16.3%, men: 14.9%). A greater percentage of female (92.3%) compared with male MOCs (69.3%; p<0.001) were assigned light duty status following MSIs.

Conclusions Mitigation of injuries during OCS events such as the obstacle course and the conditioning hike needs further investigation. The high risk of overuse lower leg injuries among women and the higher incidence of injuries among women compared with men underscore the need for further investigation of modifiable sex-specific injury risk factors.