Final Essay

Many researchers are interested in the generation of angular momentum during turning dance movements. In a study on the pirouette en dehors, researchers found that “skilled dancers generate larger vertical angular momentum as the number of turns increases by predominantly increasing the rate of momentum generation” (Kim et al., 2014). “Angular momentum is generated when the dancer applies a torque about the vertical axis by pushing sideways in opposite directions with both feet” (Laws & Sugano, 2008). The normal fourth position preparation is “ideal for creating this angular momentum as the feet exert equal horizontal forces in opposite directions to produce the twisting effect,” or torque (Kim et al., 2014). Thus, the “vertical angular momentum

Researchers in the study agreed, as they found that, “in the preparation for successful turns, approximately 60% of the dancer’s weight was over the front foot, necessitating a ‘wider’ fourth . . . position” (Kim et al., 2014). Since torque increases as the distance between the lines of action of the horizontal forces (from the two feet) increases, Laws and Sugano advocate for a wide preparation position. If the feet are farther apart, it takes less horizontal force from the feet against the floor in order to produce same torque. Additionally, they found that the total rotational momentum achieved by the body is greater if the duration of the torque is greater. To accomplish this, the dancer can increase the time in the plie during the preparation position so that the torque begins well before the heels lift off the floor (Laws & Sugano,

This is caused by a “twisting, (wind-up) motion of the trunk relative to the pelvis, and an en bloc motion of the trunk after the turn is initiated” (Kim et al., 2014). Furthermore, the contribution of the arms is critical to the angular momentum of the turn. Researchers found that the trailing arm contributes more than the leading arm to the angular momentum generation of the turn. The trailing “arm rotates in the direction of the turn so it can contribute more to the generation of angular momentum during the double-stance phase, the preparation phase, of the turn,” thus transferring angular momentum from the arms to the rest of the body (Kim et al., 2014). Both the results from the study and Laws and Sugano’s book agree that spotting, or “rotating the head relative to the rest of the body, does not change the total [angular momentum] of the body as a whole” (2008). The findings of the study suggest that “spotting has a negligible effect in generating angular momentum during the double support [preparation] phase of a pirouette. Laws and Sugano agreed that changes in body position alone cannot change total rotational momentum (Laws & Sugano,