Quantifying ballet technique through turn kinematics for injury assessment

[摘要] The most common turns in ballet, pirouettes and fouettés require precise movement to match proper technique and prevent injury. Variation in knee angle of a dancer;;s supporting leg during pirouettes of 1-5 rotations was measured using a goniometer for 12 professional and pre-professional ballet dancers. Plié angle saw no significant difference for different numbers of rotations, but the effect of gender was significant: males pliéd at least 20.3 degrees deeper than females. Average knee angle while turning was less than zero for all pirouettes, highlighting dancers;; tendency to bend their supporting knee to correct for instability, which may contribute to knee injuries. Knee angle trajectory closely matched a minimum jerk profile, indicating that dancers encode movements in angle coordinates. Knee angle was compared between pirouettes and fouettés using 2 goniometers and aerial video for 3 advanced amateurs. No difference was found in preparation plié or turn angle between turn types. Axis of rotation remained within 0.221 +/- 0.014 meters of starting position during fouettés. Maximum angular velocity of the head was nearly one and a half times that of the body during fouettés. This kinematic definition of ballet technique creates a framework for movement control of a dancer;;s lower extremities to prevent injury.

[发布机构] Massachusetts Institute of Technology