title: Ground reaction force comparison between jumps landing on the full foot and jumps landing en pointe in ballet dancers.
abstract: The purpose of this study was to describe and compare ground reaction forces (GRF) as measured by a force plate between vertical jumps of ballet dancers landing en pointe and landing on the full foot. Seven female dancers did two trials of three consecutive jumps landed by rolling through the full foot and then two trials of three consecutive jumps landing en pointe. The left leg was positioned to land on a NMFL Force Plate 9281C so as to record the GRF's at the landing phase of the jump. This data was preliminarily analyzed using inverse dynamics to find the joint reaction forces at the ankle for later interpretation. For the GRF's recorded, landing en pointe generated a mean maximum force of 531.14 N (+/- 82.28) while landing on the full foot generated 735.93 N (+/- 95.79). Thus landing en pointe created 72.17% of the force that landing on the full foot did. When jumping from and landing on pointe, due to ankle mobility restriction, jump height decreased from when the participant jumped from and landed on the full foot. The difference in jump height between the two jumping styles is a reason for the differences in GRF values. Ankle mobility restriction is related to the ankle GRF duration differences because the ankle has a wider range of motion in jumps landing on the full foot.
authors.affiliation: University of Utah, Salt Lake City, Utah, USA. chocks01@hotmail.com
authors.forename: Christina
authors.initials: C
authors.lastname: Chockley
mesh_terms: D000843:Ankle Joint / Q000502:physiology*; D001696:Biomechanical Phenomena; D003615:Dancing / Q000502:physiology*; D005528:Foot / Q000502:physiology*; D006801:Humans; D016059:Range of Motion, Articular; D013314:Stress, Mechanical