Assessment of reproducibility of thigh marker ranking during walking and landing tasks

Abstract The aim of this paper is to analyse the repeatability of marker deformation and marker ranking across subjects and motor tasks. A method based on the solidification of the thigh with optimized rototranslation was applied which used 26 markers placed on the left thigh. During five trials of landing and five trials of walking for eight participants, the deformation between the actual positions of the 26 markers and the recalled positions from solidification were calculated. Markers were then sorted and ranked from the most deformed to the least deformed. Like previous studies, marker deformation found in this paper is subject and movement-dependant. The reproducibility of the marker rankings was assessed using Kendall's coefficient of concordance. Results highlighted that the marker ranking was similar between the trials of landing and between the trials of walking. Moreover, for walking and landing the rankings were consistent across the eight subjects.