Determination of optimal placements of markers on the thigh during walking and landing

Kinematics of skin markers are affected by skin tissue artefact with respect to the bone during sports activities or locomotion. The purpose of this study is to determine the less disturbed marker’s location for walking and landing. Twenty-six markers were put on the thigh of nine male subjects. Each subject performed a static trial, a setup movement for determining a functional hip joint centre and five walking and landing trials. The marker displacements were obtained by comparing recorded marker positions and solidified marker positions based on the geometry of the static acquisition. The markers were subsequently ranked from the worst to the least deformed. The ranking of each trial for each subject was analyzed with the concordance coefficient of Kendall and descriptive statistics were used to determine the most and the least disturbed markers. The results show reproducibility between trials for each subject for the two movements. Statistical analysis shows that the most deformed markers during walking were located close to the hip and knee joints whereas the least disturbed were on the mid-thigh. The landing analysis does not permit to determine the best markers from the worst