Acute effects of the Prevent injury and Enhance Performance warm-up on potential reinjury risk factors associated with unanticipated jump landings: Study protocol for a crossover randomized controlled trial in individuals cleared for return to sports after anterior cruciate ligament reconstruction
BackgroundIn team-sports such as football or basketball, athletes need to rapidly adapt their motor plans and actions to unanticipated changes in the environment. Unanticipated jump-landing tasks have been found to elevate the risk of non-contact anterior cruciate ligament (ACL) injuries compared to an anticipated condition. ACL-reconstructed individuals may have greater difficulties to maintain neuromuscular control under unanticipated conditions exposing them to a higher reinjury risk during
... injury risk during the game. The planned trial aims to investigate the acute effects of a team-sport specific injury prevention programme on potential ACL reinjury risk factors under anticipated and unanticipated jump-landings.Methods and design:Single center randomized controlled crossover trial. Female and male ACL-reconstructed participants cleared for return to sports (≥ 6 months and ≤ 24 months post-reconstruction) will be included. In a randomized sequence and with a washout phase of one week in between, the participants will perform an injury preventive warm-up protocol (PEP; strengthening, flexibility, plyometry and agility) and a standard warm-up program (bicycle ergometer). Both interventions will last for 12 minutes and will be conducted at moderate intensity (BORG scale: 12 to 14). After each warm-up, participants will perform counter movement jumps with single-leg landings on a force plate. Prior to the jump, a left or right footprint (equally distributed) will be indicated on a screen. Under the anticipated condition, the participants will be informed before the jump that the displayed footprint will not change after take-off. Under the unanticipated condition, the participants will not know whether the target landing side will remain the same (consistent with pre-movement expectations) or change (inconsistent). Under both unanticipated conditions, this information will be displayed 0.1 second after take-off and thus approximately 0.3 seconds before landing.Parametric/non-parametric crossover-analyses (carryover-tests and crossover test) for between-conditions comparisons will be applied. Trial registration: German Clinical Trials Register, identification number DRKS00016942. Registered on May 24, 2019.