Injury prevention

Document Type



This research aimed to determine when kinetic changes place greatest risk for noncontact ACL (anterior cruciate ligament) injury during football cutting in match play. Fourteen professional football players undertook three trials of a straight line run and sidestep cutting at 30° and 60° with standardised velocity on an approved football surface. Two types of standardised studded football boots were utilised. Using inverse dynamics analyses, an eight camera gait analysis system synchronised with a force platform, determination of knee joint moments, joint forces and flexion angles were undertaken. Magnitudes and timings were compared with critical limits for ACL injury. 33- 50% of stance during cutting was associated with increased risk of ACL injury with peak valgus and internal rotational moments and anterior joint forces. Knee flexion above 30° at 22%-77% of stance appears protective. By ensuring knee control by training techniques, ACL injury risk could be reduced.