Non-contact anterior cruciate ligament (ACL) injuries represent a major problem in team sports such as handball and football. The incidence of non-contact ACL injuries is particularly high in female team sport athletes, who seem to have a 3-7 times greater risk of injuring the ACL compared to their male counterparts. To prevent the ACL injuries from happening, we need to understand the complexity of risk factors and injury mechanisms.
The objective in the present study is to increase our knowledge regarding risk factors for ACL-injuries in elite female football players. In this prospective cohort study we will investigate if various biomechanical, neuromuscular and anatomical factors can predict the risk of sustaining a future ACL-rupture. By using a cross-sectional design, we also will explore the risk factors by comparing ACL-injured and non-injured players at baseline.
All teams in the elite female football league (N=12 teams, approx 220 players per season) have agreed to participate in this study. The teams will be tested at the Norwegian School of Sport Sciences in February and March 2009. Similar screening tests will be conducted for new teams and players each season for the following two seasons (2010-11). In February 2011 all the players will be re-tested to assess the potential change in some of the variables.
After the baseline testing, ACL-injuries will be recorded for all team activities throughout the 2012 season. In addition, a complete injury registration will be conducted in the 2009 football season to describe the injury patterns in elite female football players.
Tests: The test stations include a 3D motion analysis to calculate net hip, knee and ankle joint kinetics and kinematics in drop-jumps and cutting movements.
In addition, following tests will be conducted; measures of lower extremity muscle strength and power, hamstrings flexibility, joint laxity, balance and neuromuscular control, anatomical measurements, as well as investigating genetic factors. The players will also complete a questionnaire to evaluate their knee function (KOOS), history of low back pain, and to capture psychological variables such as motivational climate and life stressors (PMSQ and LESCA).
The results from this study will enable us to identify potential risk factors for females sustaining ACL-injuries, and may reveal important information on how to optimize the effect of current preventive training programs.