Increase in Injury Risk With Low Body Mass and Aerobic-Running Fitness in Elite Australian Football

Abstract

To assess the relationships between player characteristics (including age, playing experience, ethnicity, and physical fitness) and in-season injury in elite Australian football. Single-cohort, prospective, longitudinal study. Player characteristics (height, body mass, age, experience, ethnicity, playing position), preseason fitness (6-min run, 40-m sprint, 6×40-m sprint, vertical jump), and in-season injury data were collected over 4 seasons from 1 professional Australian football club. Data were analyzed for 69 players, for a total of 3879 player rounds and 174 seasons. Injury risk (odds ratio [OR]) and injury severity (matches missed; rate ratio [RR]) were assessed using a series of multilevel univariate and multivariate hierarchical linear models. A total of 177 injuries were recorded with 494 matches missed (2.8±3.3 matches/injury). The majority (87%) of injuries affected the lower body, with hamstring (20%) and groin/hip (14%) most prevalent. Nineteen players (28%) suffered recurrent injuries. Injury incidence was increased in players with low body mass (OR=0.887, P=.005), with poor 6-min-run performance (OR=0.994, P=.051), and playing as forwards (OR=2.216, P=.036). Injury severity was increased in players with low body mass (RR=0.892, P=.008), tall stature (RR=1.131, P=.002), poor 6-min-run (RR=0.990, P=.006), and slow 40-m-sprint (RR=3.963, P=.082) performance. The potential to modify intrinsic risk factors is greatest in the preseason period, and improvements in aerobic-running fitness and increased body mass may protect against in-season injury in elite Australian football.