A narrow bimalleolar width is a risk factor for ankle inversion injury in male military recruits: A prospective study

Abstract

Background: Ankle inversion injuries are one of the most common and burdensome injuries in athletic populations. Research that prospectively identifies characteristics associated with this injury is lacking. This prospective study compared baseline anthropometric and biomechanical gait characteristics of military recruits who sustained an ankle inversion injury during training, with those who remained injury-free. Methods: Bilateral plantar pressure and three-dimensional lower limb kinematics were recorded in 1065 male, injury-free military recruits, during barefoot running. Injuries that occurred during the 32-week recruit training programme were subsequently recorded. Data were compared between recruits who sustained an ankle inversion injury during training (n=27) and a sample (n=120) of those who completed training injury-free. A logistic regression analysis was used to identify risk factors for this injury. Findings: A narrower bimalleolar width and an earlier peak pressure under the fifth metatarsal were predictors of ankle inversion injury. Those who sustained an ankle inversion injury also had a lower body mass, body mass index, and a smaller calf girth than those who completed training injury-free. Interpretation: Anthropometric and dynamic gait characteristics have been identified that may predispose recruits to an ankle inversion injury during Royal Marine recruit training, allowing identification of recruits at higher risk at the start of training.