Classification of Runners with High versus Low Hip Adduction Based on Measures of Pelvis and Femur Morphology.

Abstract

To determine the most relevant pelvis and femur morphological characteristics for differentiating runners with high versus low hip adduction during running. Fifteen female and 14 male runners underwent instrumented kinematics analysis of overground running and computed tomography scanning of pelvis and femur. The peak hip adduction angle during the stance phase of running was identified for each participant. Using the cohort average of the peak hip adduction angle as the classifying threshold, participants were categorized into high or low hip adduction groups. To determine the most relevant morphologic features for discriminating high and low hip adduction runners, a feature selection-based support vector machine classification analysis was performed. Of the 15 morphology variables examined, femoral head anteversion and femur length were shown to be the best discriminant variables for group classification. Together, these variables achieved a prediction accuracy of 0.93, sensitivity of 1.0, and specificity of 0.88. Our results highlight the importance of femur morphology in contributing to increased hip adduction during running.