Can a Strength and Technique Intervention Reduce Knee Abduction Moment in Young Female Handball Players

BACKGROUND:

ACL injuries are the number one problem in female elite ball/team sports due to its relatively high incidence and serious short- and long-term consequences. Typically injuries occur in actions that are essential for the game, i.e. landings and cutting maneuvers, imposing a challenge for risk reduction strategies.

The consequences of an ACL injury are manifold for the players. They not only reduce quality of life but also lead to a loss of social contacts due to missed training sessions what can be difficult, especially for younger players. Additionally, there are serious long-term consequences with a high likelihood of early osteoarthritis, lasting pain and disability. Also the risk of suffering a second ACL injury after returning to sport is high. In fact, as many as 20-30% of female players returning to play after an ACL injury end up with a new ACL injury in the same or contralateral knee, which makes prevention of a first injury even more important.

Video analyses of ACL injuries strongly suggest that biomechanics is important in injury causation. Novel model-based image-matching techniques have shown that valgus movement occurs shortly after initial contact of the foot with the ground. This implies that knee abduction loading is a likely causative factor. Still, video-based methods have limitations in their accuracy and detail level. To address this knowledge gap, the Oslo Sports Trauma Research Center has carried out the world's largest prospective risk factor study on ACL injuries to date-with multiple data collections between 2007 and 2014.

The most recent analyses indicate that there are clear associations between biomechanics of cutting maneuvers and injury risk. Specifically knee abduction moments seems to be greater in players who later go on to sustain an injury and can be affected by the players' cutting technique variables (width of cut, hip abduction, foot rotation, torso movement/rotation, hip rotation, knee valgus, knee flexion, cutting angle, cutting time, approach speed). These findings may simply reflect that injuries take place in cutting maneuvers and underline the importance of investigating such maneuvers, which closely mimic the real-life setting.