Is There a Predictable Value of the Drop Vertical Jump Test for Running Gait Injury Risk?

Abstract

PURPOSE: A three-dimensional (3D) motion analysis of running gait is often used to identify modifiable lower extremity biomechanical risk factors, but can be time consuming and costly. The Drop Vertical Jump (DVJ) test when combined with the Landing Error Scoring System (LESS) can easily be done in the field to assess lower extremity coordination and injury risk. The purpose of this study was to determine if correlations existed between biomechanical variables of the DVJ and a 3D gait analysis. Positive findings would indicate that the DVJ may serve as a simple surrogate for the running analysis to quickly screen for lower extremity injury risk. METHODS: 24 runners (26.1 ± 8.6 yrs; 27.7 ± 11.3 miles/wk; 16 Male, 8 Female) participated. During one testing session, a 3D motion analysis and an instrumented treadmill were used to capture and determine lower extremity kinematics, ground reaction forces (GRF) and knee moments during the gait cycle. Subjects completed five DVJs and a gait analysis at a self-selected running speed (6.7 ± 0.9 mph). Data were gathered on the dominant leg for both the DVJ and the gait analysis (1 left dominant). LESS scores were calculated through frontal and sagittal plane videos of the DVJ using a score from 22 items. Individual LESS items were selected based on similar measures that could be captured in the 3D gait analysis: asymmetric motion of feet and knees in the sagittal and frontal planes, foot contact patterns and overall impression. RESULTS: Significant associations existed between maximal knee flexion angle (sagittal plane 3D running) and overall LESS score (r=-.791; p<0001). There were no other significant associations between lower extremity kinematics, GRFs and knee moments and LESS items and overall score. There were also no significant associations between DVJ biomechanical variables and the 3D gait measures. CONCLUSION: Contrary to our expectation, associations between 3D gait, DVJ and LESS were minimal. A possible explanation could be that the dual-leg DVJ test may not be able to account for factors of balance and stability that are critical for the single-leg nature of running. A single-leg DVJ may be a more accurate field test when predicting running-related injuries.