The Vertical Drop Jump is a Poor Screening Test for ACL Injuries in Female Elite Soccer and Handball Players
Krosshaug T, Steffen K, Kristianslund E, Nilstad A, Mok KM, Myklebust G, Andersen TE, Holme I, Engebretsen L, & Bahr. Am J Sports Med. 2016; 44: 874-883. DOI: 10.1177/0363546515625048
Take Home Message: Performance on the vertical drop jump landing task was not found to be associated with anterior cruciate ligament injury risk in a group of female handball and soccer athletes.
We have had quite a few posts on Sports Med Res surrounding the short- and long-term effects of anterior cruciate ligament (ACL) injury. However, we still need to determine how to best identify who may be at risk for ACL injury so that we can optimize prevention strategies. Many try to screen athletes with the drop jump landing task, but it remains unclear whether this test is predictive of subsequent injury. Therefore, this study’s authors aimed to prospectively evaluate the accuracy of the drop jump landing task in predicting ACL injury. During preseason screening tests between 2007 to 2014, 710 female handball and soccer players performed the drop jump landing task off of a 30 cm box. Sixty-seven athletes had a previous history of ACL injury before baseline testing. The authors evaluated motion analysis and force plate measures during each athlete’s vertical drop jump test and focused on five factors: 1) knee valgus angle at initial contact, 2) peak knee abduction moment, 3) peak knee flexion angle, 4) peak vertical ground-reaction force, and 5) medial knee displacement. The authors tested if these 5 measurements were associated with a non-contact ACL injury. During the study 42 athletes had a noncontact ACL injury, with 12 of the previously injured participants having suffered another ACL injury. Overall, the authors reported that a majority of the factors were not related with increased ACL injury risk. Only greater medial knee displacement was associated with an increased ACL injury risk among those who previously injured their ACL. The authors found that this measure lacked predictability due to its poor combined sensitivity and specificity. Interestingly, there was no side-to-side differences between injured and uninjured legs in any of the variables of interest in those that suffered a knee injury.
The findings of this study are interesting because these authors found that a commonly used drop jump landing task is not a good screening tool to predict ACL injury risk. The strongest risk factors associated with suffering an ACL injury were a previous ACL injury and medial knee displacement. This study followed a large cohort and saw about 50 new knee injuries. The authors noted that this is still a relatively small number of knee injuries and there are numerous causes of a knee injury, which may make it hard to predict who will get injured. It would have been interesting if the authors could have taken annual measurements for individuals in the study to determine if there were changes as athletes aged, or when they suffered other lower extremity injuries (e.g., ankle). The authors analyzed a small cohort (107 players) with a test-retest and found small changes that were different in 4 of the 5 measurements. However, it might be interesting to see if these changes affect a person’s injury risk or patient-reported outcomes. The Landing Error Scoring System is based on a similar task; however, rather than a drop jump landing, participants jump off a box and out to a distance half of their height. The authors failed to state the distance associated with the task in this study, and the distance an athlete jumped out may differentiate these two screening tools. While motion analysis has higher sensitivity, it may be interesting to see how these landing error scores would compare to the motion analysis data in terms of predicting ACL injury. Ultimately, these authors found that objective measures from a drop jump landing task has poor predictability, and we should consider utilizing other screening measures for ACL injury risk.
Questions for Discussion: How do you typically manage ACL screening within your clinical setting? Are there any other ACL screening tools that you are interested in learning more about?
Written by: Nicole Cattano
Reviewed by: Jeffrey Driban