Effect of Foot Orientation on Landing Impact Forces Following a Drop Jump in Ballet Dancers.

Abstract

Introduction: Jumping is a fundamental element of classical ballet, often performed with the feet turned out, in a position known as en dehors, achieved through hip external rotation. Experience level and impact attenuation strategies may play a crucial role in reducing injury risk during jump landings. This study aimed to investigate the impact during drop jump landings in en dehors versus parallel foot orientation in experienced ballet dancers. Method: Seventeen experienced ballet dancers (aged 18-31 years, with an average of 13 years of experience) and 15 controls (aged 20-32 years old) who were not dancers and did not engage in regular physical activity, participated in the study. Participants performed drop jumps from a 30 cm high block, landed on two force platforms, and immediately executed a maximum vertical jump with feet in en dehors position or parallel. Maximum vertical ground reaction force, time to reach this maximum, maximum rate of force development during drop landing, and maximum height of the jump performed immediately after drop landing were calculated and compared between groups and foot orientations. Results: Time to reach the maximum vertical ground reaction force was shorter in the en dehors compared to parallel foot orientation, with no significant group differences. Ballet dancers achieved higher vertical jumps after the drop landing compared to controls. Conclusions: Long-term classical ballet practice does not lead to lower impact landings in en dehors compared to parallel foot orientation. Ballet dancers may take more advantage of the impact and rebounding for performing the subsequent vertical jump.