Sex-related Differences On Neuromuscular-cognitive Assessments In Healthy Marines

The number of active duty females in the U.S. Armed Services is steadily increasing. Female service members have demonstrated greater musculoskeletal injury risk compared to male counterparts. Exploring sex differences in novel neuromuscular-cognitive assessments may provide insight into musculoskeletal injury risk disparities. PURPOSE: Assess sex-related differences during three neuromuscular-cognitive assessments. METHODS: 674 entry-level U.S. Marines at the School of Infantry West (29.4% females; 19.89 ± 2.38 years) completed three neuromuscular-cognitive assessments: single-leg memory hop (SLMH), run decide (RD), and reactive agility (RA). For the SLMH, subjects performed a single limb hop as quickly and far as possible when a sensor in front of them flashed blue during a sequence of various colors. Reaction time (RT) and hop distance were averaged for three trials. For RD, subjects rose from a prone position as quickly as possible and ran past two sensors that triggered a 45o cut to the left or right. Decision-making (time to deactivate the target sensor) and total time to complete the task were averaged for two trials. For RA, subjects stood in the center of a 4x4m square. A sensor in each corner illuminated a unique color. They identified and deactivated the blue sensor, returned to the center, and repeated the task nine additional times. RT and total time were averaged for two trials. Separate MANOVAs with post hoc one-way ANOVAs with Cohen’s D effect size compared each variable between females and males for each assessment. RESULTS: The MANOVAs for the SLMH, RD, and RA were statistically significant (p < 0.0001). Females performed slower for all variables of RD (d:1.07-1.64) and RA (d:0.56-0.84). For SLMH, females had shorter hop distance (d = -1.32) but similar RT (d = 0.03) (Table 1). CONCLUSIONS: Females had lower performance on the neuromuscular-cognitive assessments than males indicating they may require different considerations for assessing injury risk. Supported by: This work was funded by the Office of Naval Research (N00014-21-12892) under WU# 62331. The study protocol was approved by the University of Kentucky Institutional Review Board (#62029) in compliance with all applicable federal regulations governing the protection of human subjects. The views expressed are the authors and do not reflect the official policy or position of the Uniformed Services University, Department of Defense, Department of Veterans Affairs, or the U.S. Government.