Evaluation of the Estimation Method on the Hip Joint Centre Location During Instep Kicking Motion (P217)

Abstract

The purpose of this research was to evaluate the estimation methods ofthe hip joint centre (HJC) location for calculating kinematic parametersof knee and hip joints during dynamic movement, in this reserch, instepkicking motion. Twelve skilled soccer players participated in theexperiment. To estimate the HJC location, they were instructed to do adhoc movements including hip flexion/extension and abduction/adductionmovements performed on several planes of different orientations,followed by a circumduction movement. Then, subjects performed theirmaximal instep kick, which were recorded using motion capture system at250Hz. The coordinates of the HJC were estimated using three methods andcompared. The first used marker coordinates on left and right greatertrochanters, the second empirical relations between the HJC location andthe length between anterior Superior illiac spines, which had beencalled predictive method, and third bias compensated least squaresmethod, which had been called functional method. Then, maximal hipextention and knee flexion angles during instep kicking motion werecalculated based on three methods, and compared statistically. As aresult, the hip joint centre location estimated by first method changedso much in the pelvic anatomical frame during dynamic exercise, andmaximal hip extension and knee flexion angles were different fromresults by other two methods significantly. However, predictive methodsgave almost the same results as functional method which had been said tobe most accurate method in a previous study. Consequently, method usingmarkers on the greater trochanters could not be appropriate forkinematic analysis during dynamic exercise, and predictive method wasrecommended for use because of its accuracy and easiness forapplication.