Poor Pelvic Control During A Knee Lift Test Is Associated With Increased Risk Of Knee Injuries

Abstract

PURPOSE: To investigate whether deficits in stance leg, hip and pelvic stability during a standing knee lift test are associated with increased risk of non-contact knee and ankle injuries in youth team sports. METHODS: At baseline, 263 basketball and floorball players (age range 12–21 y.) participated in a standing knee lift test using 3-dimensional motion analysis. The test was a modified version of the Trendelenburg test to assess stance leg and hip stability. Two trials per leg were recorded from each participant and mean value was used in the analysis. The biomechanical variables calculated were peak anterior pelvic tilt angle (APT) and peak lateral pelvic drop angle (LPD). The APT and LPD were categorized into two groups using the median of the cohort: low group (values less than median value) and high group (values larger than median). All new non-contact knee and ankle injuries, as well as match and training exposure, were then recorded for 12 months. Cox regression models were used to calculate hazard ratios (HRs) and 95% CIs. RESULTS: A total of 16 new non-contact knee injuries (of which eight were ACL ruptures, all affecting female players) and 36 new non-contact ankle injuries were registered during the study period. Athletes displaying high lateral pelvic drop angles were at increased risk of knee injuries (adjusted HR for high versus low group 4.22; 95% CI 1.34–13.3). A borderline significant (p=0.05) association was found between high lateral pelvic drop angles and ACL injury risk in female athletes (adjusted HR for high versus low group 8.14; 95% CI 0.97–68.6). No potential ankle injury risk factors were found. A receiver operating characteristic curve analysis for the LPD and knee injuries showed an area under the curve of 0.60, which indicates poor combined sensitivity and specificity of the test. CONCLUSIONS: Poor pelvic control, with increased lateral pelvic drop, is associated with increased risk of non-contact knee injuries among young team sport players. However, the knee lift test cannot predict non-contact knee injuries in youth team sports. Supported by the Finnish Ministry of Education and Culture, and Competitive State Research Financing of the Expert Responsibility area of Tampere University Hospital (Grant 9S047).