Lower limb injuries in New Zealand defence force personnel: Descriptive epidemiology

Objective: To describe the epidemiology of lower limb injuries in the New Zealand Defence Force (NZDF). Method: Data from all NZDF lower limb injury claims from an 11-month period were examined for type, site, and circumstances of injury. Both injury codes and narratives were analysed, allowing each injury event to be classified according to mechanism of injury, object involvement, and activity at the time of injury, as well as type and site. Results: The commonest lower limb musculoskeletal injuries were ankle sprains or strains (35%) and knee sprains or strains (16%). Most commonly, injuries were due to acute over-exertion (37%), involved no other person (50%), and occurred while running (28%) or playing team sports (25%). The injury rate for recruits was more than five times that of trained personnel. Conclusions: Potential interventions should target ankle sprains primarily, but also knee sprains and fractures. Fractures, while accounting for only 6% of lower limb injuries, should be a priority because of their high medical and time-lost costs. Interventions must also take into account the high incidence of injuries involving individuals alone and sustained during recruit training. The study also demonstrated that analysis of military injury narratives provides valuable extra information on injury causation and the circumstances of injury, and allows more accurate characterisation of the injury process. Implications: This study will provide the basis for development of an injury prevention strategy for lower limb training injuries in the NZDF.