Modification of impulse generation during piqué turns with increased rotational demands

Abstract

During initiation of a piqué turn, a dancer generates impulse to achieve the desired lateral translation and whole-body rotation. The goal of this study was to determine how individuals regulate impulse generation when initiating piqué turns with increased rotational demands. Skilled dancers (n=10) performed single (∼360°) and double (∼720°) piqué turns from a stationary position. Linear and angular impulse generated by the push and turn legs were quantified using ground reaction forces and compared across turn conditions as a group and within a dancer using probability-based statistical methods. The results indicate that as the rotation demands of the piqué turn increased, the net angular impulse generated increased whereas net lateral impulse decreased. Early during turn initiation, the free moment contributed to angular impulse generation. Later during turn initiation, horizontal reaction forces were controlled to generate angular impulse. As rotational demands increased, the moment applied increased primarily from redirection of the horizontal reaction force (RFh) at the push leg and a combination of RFh magnitude and moment arm increases at the turn leg. RFh at each leg were coordinated to limit unwanted net linear impulse. Knowledge of observed subject-specific mechanisms is important to inform the design of turning performance training tools.

Quantifying performance on an outdoor agility drill using foot-mounted inertial measurement units

“…Rapid changes in direction, signaled by short duration turn phases, require the rapid generation of linear and angular impulses from ground reactions. These impulses accelerate the center of mass of the body in a new (desired) direction and also re-orient the body towards that direction [ 15 , 16 , 35 ]. Compared to lower performers, higher performers in our study exhibited shorter duration ground contacts and generated larger horizontal ground reactions that also had larger components tangent to (less normal to) the turn trajectories.…”

“…Turning agility can be defined as the ease with which a body changes direction [ 14 ]. Changing direction requires simultaneously satisfying linear and angular momentum requirements to redirect the body in the new (desired) direction [ 15 , 16 ]. Agility has been studied using a range of turning-while-running tasks with agility performance commonly defined by the time to complete the agility task [ 14 , 17 ].…”

Gait-Phase Specific Transverse-plane Momenta Generation During Pre-planned and Late-cued 90 Degree Turns While Walking

“…1a). 16,17,33 The purpose of this study was to examine strategies used by healthy young adults during each gait phase to accomplish the transverse-plane mechanical objectives of pre-planned and late-cued 90° turns. We hypothesized that in pre-planned and late-cued turns to the left, (1) during right single support phase, the greatest change in COM leftward linear velocity and average COM leftward linear acceleration are generated to redirect the COM trajectory towards the new direction of travel, and (2) during double support phases with the left foot in front of the body (left double support), the greatest change in transverse-plane angular momentum (Ht) and average transverse-plane moment are generated to rotate the body to the desired facing direction.…”

“…Prior turning research in athletic maneuvers has revealed that generating angular impulse by redirecting ground reaction forces during double support facilitates mitigating extraneous linear impulse and avoiding con icts between rotation and balance maintenance or COM translational goals. 16,17,33,34 For instance, during single support, if a large moment is applied from the ground reaction force, this force needs to be directed away from the COM, which may accelerate the COM in an undesired direction, or a direction away from the base of support (Fig. 1b).…”

The Effect of Footwear on Free Moments During a Rotational Movement in Country Swing Dance

“…[1][2][3][4][5] Understanding the biomechanical interaction between dancers and floors could also provide insight for performance training in dance. 6 One area that has not been studied is how footwear may affect the twisting loads applied to the lower extremities during rotational movements.…”