Knee rotation in classical dancers during the Grand Plié: A three-dimensional videographic analysis

The purpose of this thesis was to investigate and compare the external longitudinal rotation (ELR) at the knee during grand pliés performed in three different classical ballet leg positions, 2^nd, 3 ^rd and 4^th by professional female ballet dancers. A seven-segment model of the lower human body (pelvis, right/left thigh, right/left lower leg, right/left foot) was defined. 4 to 5 light-reflective spherical markers were placed over each segment. Plié movements were captured by two industrial quality video cameras. Marker locations were digitized using Ariel Dynamics (APAS™) software.

This thesis supports the argument that the grand Plié is not just an extension of the demi Plié. Because ELR at the knee has been named as one of the more serious pre-disposing factors to knee injury, the high ELR values recorded in this thesis at Instant 3 indicate that the movement should indeed be performed with discrimination. (Abstract shortened by UMI.)