No Association Between Static and Dynamic Postural Control and ACL Injury Risk Among Female Elite Handball and Football Players: A Prospective Study of 838 players
Steffen K, Nilstad A, Krosshaug T, Pasanen K, Killingmo A, & Bahr R. Br J Sports Med. 2017; 51:253-259. doi: 10.1136/bjsports-2016-097068
Take Home Message: Balance assessments were not associated with anterior cruciate ligament injury risk among elite female handball and soccer athletes.
Clinicians and researchers are seeking screening tests to determine who is at greater risk for an anterior cruciate ligament (ACL) injury. Balance exercises are often integrated into ACL prevention programs since many believe poor balance is associated with increased lower extremity injury risk. However, there is little research to quantify the ACL injury risk associated with balance deficits. The authors of this prospective study screened 838 elite female handball and football players and followed them to see if they suffered an ACL injury over an eight-year period. After an initial baseline screening, new athletes and athletes on new teams to the premier leagues were evaluated. Balance screening consisted of a single leg stabilization on a foam pad on a balance platform (static and following a drop down), as well as dynamic stability through a simplified star excursion balance test. The investigators assessed balance on both legs. They also assessed the consistency of the balance assessment among a subset of people at 1 to 5 years after the initial screening. The authors recorded all complete ACL injuries, which were verified with MRI or surgery, and asked the athletes if the injury was direct contact, indirect contact, or noncontact. Eighty-one players reported a history of ACL injury prior to screening. Among these athletes, 12 players experienced another ACL injury during the follow-up period. Over the follow-up period 67 athletes had 80 ACL injuries. The most common ACL injury mechanism was non-contact, and there was a total of 55 new non-contact ACL injuries analyzed during the study period. Within those that suffered noncontact ACL injuries, there were no differences between the uninjured and injured legs for static balance, drop-down balance, or dynamic balance. There were also no differences between those who did and did not suffer a noncontact ACL injury in any of the 3 baseline balance assessments. The only significant finding was that a previous ACL injury history tripled the risk for suffering another ACL injury.
This study shows that baseline balance data are poor predictors for ACL injury risk. The authors noted that these balance tests had poor reproducibility because people demonstrated an improvement over time. These assessments may be inappropriate among elite female athletes. Therefore, we need to wonder if another test may be better suited for screening or if screening needs to occur every preseason. It would have been interesting to see how balance assessments changed over the years, and whether there were any clinically meaningful changes over the course of the study. The authors indicated that fatigue may have been a factor in how the players performed on the tests. It would be interesting to further investigate this idea. Some people think that fatigue can adversely affect performance and increase injury risk. Hence some think that you should try to prevent fatigue to prevent injury. Most importantly, we need to increase our efforts in primary prevention of an ACL tear since that is the strongest risk factor for suffering an ACL tear. Bottom line based on this research study, is that clinicians lack a balance-screening test to identify elite athletes at risk for ACL injury. This study also highlights that primary prevention among young athletes is critical.
Questions for Discussion: What do you use for ACL injury risk assessments? What are your thoughts on fatigue and injury risk?
Written by: Nicole Cattano
Reviewed by: Jeffrey Driban