Contribution of the Pelvis to Gesture Leg Range of Motion in a Complex Ballet Movement

Abstract

Eight skilled ballet dancers performed grand rond de jambe en l'air with the right leg as gesture leg at heights of 90° and 105° as well as their maximal active range of motion (MAR). Three-dimensional motion analysis was performed to quantify the pelvis and gesture-leg motions and to investigate the interaction between pelvic motion and increased leg height. Orientation angles of the pelvis and relative orientation angles of the gesture leg to the pelvis were computed. Events for analysis were defined based on the gesture leg motion, and the pelvis and gesture leg orientation angles at these events as well as the peak values were obtained. One-way repeated-measure ANOVA was used to determine differences among leg heights (p < 0.05). In grand rond de jambe of 90° or higher, dancers gradually increased pelvic motion, especially anterior-posterior and lateral tilts, as the gesture leg height increased. Approximately 4% to 16% of the leg height at end of the ascending motion and 60% of the leg height at initiation of the descending motion were explained by posterior and anterior pelvic tilt, respectively. Maximum left lateral pelvic tilt was equivalent to approximately 45% to 60% of the maximum hip abduction. As the leg height requirement increased, dancers achieved this height primarily by increasing pelvic motion. Gesture leg motion revealed only a minor contribution. In spite of literature in dance pedagogy that suggests that the pelvis should remain immobile during grand rond de jambe, the authors conclude that the pelvis is the primary contributor to the gesture leg range of motion for increased vertical angle demands.