Medicine and Health Sciences


Biomechanical control of balance has been analyzed in bipedal stance and among dancers performing a single-leg stance on retiré position. However, research of the dynamic stability throughout a pirouette performed en dehors on demi-pointe has not been conducted. The purpose of this study was to compare the center of mass (COM), center of pressure (COP), and their relationship during a pirouette executed by a professional and an elite amateur dancer. This analysis provides a descriptive and comparative exploration of balance control in the ballet and jazz pirouette. The differences in position of COM relative to the COP, between an elite amateur and professional dancer, can indicate faults leading to weaker vertical stability. The findings of this study may be applicable to the dance community and can help instructors identify potential mechanisms by which to improve balance in dancers, therefore increasing overall success during the performance of a pirouette. Participants of the study included one female elite amateur dancer with 18 years of experience and one male professional dancer with 30 years of dance experience. Anatomical marker placement utilized the Vicon Plug-in Gait (PIG) and Oxford Foot biomechanical models. Marker trajectories were recorded using eight Vicon MX-T40 cameras at 120 Hz (Oxford Metrics, Oxford, UK) and Nexus motion capture software (Vicon Motion System Ltd., Oxford Metrics, UK). Position data were synchronized with ground reaction forces collected at 1200 Hz with floor embedded force plates (Advanced Mechanical Technology, Inc,. Watertown, MA). Twelve trials of pirouettes were performed in each style of dance, with the best overall pirouette (chosen by the dancer) used for data analysis by means of a custom MatLab program and Vicon Polygon. Based on the dancer’s chosen pirouettes, the professional dancer exhibited superior control of the position of the COM over the COP. Average COM relative to COP displacement throughout the turn (omitting preparation and toe-off displacement) indicated smaller magnitudes for the professional dancer in both ballet and jazz styles. Peak displacement values of the COM relative to the COP, for both dancers, occurred at toe-off. The overall motion of the COM was similar for both dancers, as was COM acceleration patterns. These results suggest that improving a dancer’s control of balance may improve overall technique during a turn. The mechanisms by which greater control of the COM is made possible were likely utilized in greater capacity by the professional dancer compared to the elite amateur dancer.