Association between preseason functional tests and injuries in youth football: a prospective follow-up

This prospective cohort study aimed at identifying player-related risk factors for injuries in youth football as determined by extensive preseasonal screening. All male U15-U19 players from a regional football school (season 2007-2008; n = 67) underwent preseason evaluations assessing physical fatigue, emotional stress and injury history (questionnaire), anthropometric variables, general joint laxity (Beighton score), lower limb coordination (functional hop tests), aerobic fitness (shuttle run test), strength of knee extensor and flexor muscles (isokinetic tests), static and dynamic balance (force plate tests), and explosive strength (jump tests on force plate). Football exposure and all football-related injuries (n = 163) were recorded during the entire subsequent season (44 weeks). Total injury incidence was 10.4 injuries/1000  h and was higher in competition than in training [relative risk = 3.3; CI(95%) (2.39; 4.54); P < 0.001]. Lower limb injuries were most frequent (87%). Acute contact injuries represented 37%, while intrinsic (noncontact and chronic) injuries amounted to 63%. Of all the variables tested, only physical fatigue was significantly associated with injury, as revealed by univariate and multivariate analyses. The same result was observed when considering only intrinsic injuries as outcome. A single preseason test session may be of limited interest in the framework of an injury prevention strategy.