Is the Symmetry of Classical Ballet Positions Perfect?

Abstract

It is expected that in classical ballet dancers would be able to execute all the techniques symmetrically from the right as well as from the left side of the body. This study aimed to evaluate the symmetry of kinematic parameters of hip joints, knee joints, and foot progression angle of the left and right lower extremities (LE) in five classical ballet positions, as well as the symmetry of active and passive turnout and range of passive hip external rotation. The experimental testing involved 12 female pre-professional ballet dancers. Three measurements of range of motion, made using a standard goniometer, were carried out to characterize the study group. Kinematic data of left and right LE in the five classical ballet positions were recorded using a motion capture system. The comparisons revealed significantly lower (p < 0.01) hip external rotation values by 9.8% (1st position), 5.4% (2nd position), and 8.5-11.8% (3rd position) for the right LE than the left LE. Moreover for 3rd, 4th and 5th positions, there was significantly higher (p < 0.05) hip external rotation values by 7.0%-27.2% in the back LE than the front LE. In 4th position there was asymmetry in foot progression angle with significantly lower values (p < 0.01) by 5.3% in the front LE (left) than the back LE (right). In case of goniometric measurements, the results showed significantly higher (p < 0.05) passive hip external rotation values by 10.8% for the right LE than the left LE. The perfect ballet symmetry pursued by dancers is not in fact so ideal. The most astonishing result was the existence of statistically significant differences in hip external rotation in the case of the 1st and 2nd positions.