Do cervical spine injury patterns and musculoskeletal characteristics differ by sex in soldiers exposed to head-supported mass? A cross-sectional study among special operations combat soldiers.

INTRODUCTION: Female military personnel are increasingly performing high-risk tasks in operationally challenging environments, including roles that require routine exposure to head-supported mass (HSM). However, sex-specific differences in cervical spine (CS) injury, pain and musculoskeletal characteristics among special operations combat soldiers (SOCSs) remain poorly understood. The purpose of this study was to examine potential differences in CS injury, pain and musculoskeletal characteristics in male and female SOCSs. METHODS: The study population included 297 SOCSs, including 284 males and 13 females. Data were collected on CS injuries, HSM exposure, military demographic information, CS pain and CS range of motion and strength. Acute injury incidence rates were calculated retrospectively for the preceding calendar year. RESULTS: The acute injury incidence rate was higher in females than males, but this difference was not statistically significant, with a wide CI due to the small female subgroup (risk ratio (RR): 2.09, 95% CI 0.88 to 4.95). Females also reported fewer years of HSM exposure and fewer parachute jumps. A greater proportion of females (69%) sustained one or more parachute-related injuries compared with males (43%). Furthermore, female injuries had a greater operational impact, as they were most likely to result in time loss or restricted duty (females: 44%, males: 28%), medical professional visits (females: 73%, males: 53%) and require treatment (females: 87%, males: 60%). Both sexes reported high rates of CS pain during military activity (females: 92%, males: 88%). While CS range of motion was similar between sexes, females were significantly weaker across all strength measures. CONCLUSION: Females in this SOCS cohort demonstrated a higher observed, but statistically nonsignificant, acute CS injury rate compared with males. These exploratory findings suggest that the lower strength capabilities of females, combined with identical equipment loads and similar operational demands, may contribute to the more frequent pain and injury incidence in females. Future research should investigate this association in larger cohorts and explore how CS strengthening, equipment modification and training demands may mitigate risk for female SOCSs.