Morphological and skill-related fitness components as possible predictors of injuries in elite female field hockey players
Introduction: The incidence of injury in female field hockey players is high, but there is little data on the physical demands of the game or the injury risk factors. Objective: To establish an athletic profile of elite female field hockey players and to determine if morphological or skill-related factors measured in the pre-season can predict injury in the in-season. Methods: Thirty female field hockey players comprising the South African national field hockey team underwent pre-season testing. These tests included anthropometry, balance, flexibility (sit and reach test), explosive power (vertical jump test), upper and lower body strength (bench and leg press), core strength, speed (10 m, 40 m and repeated sprint test with and without a hockey stick), agility (Illinois test) and isokinetic testing of the ankle. Also included was a questionnaire to collect information on demographic data, elite-level experience, playing surface, footwear and injury history. Injuries in training and matches were recorded prospectively in the subsequent season using an injury profile sheet. Players reporting an injury were contacted to collect data regarding injury circumstances. Univariate and multivariate regression analyses were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for ±1 standard deviation of change. Results: A total of 87 injuries were recorded with ligament and muscle injury the most frequent. The highest incidence of injury was the ankle joint followed by the hamstring muscles and lower back respectively. Univariate analyses showed that ankle dorsiflexion strength was a very strong predictor of ankle injuries (p=0.0002), and that ankle dorsiflexion deficit (p=0.0267) and eversion deficit (p=0.0035) were significantly good predictors of ankle injury. All balance indices, i.e. anterior/posterior (p=0.0465), medial/lateral (p<0.0001) and overall (p<0.0001), constituted the other pre-season performance measures showing significant potential to predict ankle injury. For lower leg injuries, univariate associations were found with ankle inversion deficit (p=0.0253), eversion deficit (p=0.0379) and anterior/posterior balance index (p=0.0441). Conclusion: Dorsiflexion strength and all balance indices were strong predictors of ankle injury while ankle inversion deficit, eversion deficit and anterior/posterior balance were associated with lower leg injuries in elite female field hockey players.