The Biomechanical Demands of Ballet - Implications for Performance Profiling and Injury Aetiology

Abstract

allet epidemiology audits have established a high prevalence of ankle injury. However, aetiological research specific to these injuries in a ballet context is limited. Given the mechanical complexity of ballet, the aim of the current thesis was to conduct a multi-modal biomechanical investigation of ballet-specific movement. In study 1, amateur female ballet dancers completed a testing battery containing the following seven ballet-specific jump landing tasks; jeté, jeté step, échappé, sissonne, sissonne pas de bourres (PDB), temps levé and jeté en tournant (ET). A multi-camera automated motion capture system with integrated, synchronous force plate analysis was used to quantify kinetic and ankle joint kinematic responses to the movement battery. Resultant biomechanical responses were task-dependent, and bilateral symmetry was evident across all movements. Study 2 quantified the electromyographic responses to the same movement battery, again demonstrating bilateral symmetry, and mirroring the hierarchical ordering of movement demand demonstrated in study 1. Study 3 evaluated bilateral isokinetic ankle strength (Peak Torque, Angle of Peak Torque, Functional Range, Angle-Specific Torque, Dynamic Control Ratios) using a dynamometer (Biodex System 4 pro), with a testing protocol supported by the joint angular velocity and displacement data obtained during study 1. Ballet dancers are eccentric inversion strength dominant, exacerbated at ≥ 60°·s-1, and demonstrate lateral symmetry in strength which may reflect a chronic training adaptation.
Study 4 utilised accelerometry to quantify planar mechanical load response to the movement
battery, consistently identifying the task-dependent hierarchy of movement response, and
demonstrating strong correlations (r ≥ 0.59) with planar ground reaction force measures in study 5. Study 6 utilised the greater ecological validity afforded by accelerometry to investigate the mechanical implications of consecutive ballet performances. There was some evidence of a fatigue response between bouts, and anatomical location of the accelerometer device was an important consideration when interpreting movement response. The studies comprising this thesis offer a contemporary approach to conducting biomechanical analyses in ballet. Inclusion of a ballet-specific movement battery offers a novel dimension and increases ecological validity. Synergy and cohesion within a multi-modal design was reflected in the responses across data collection tools, demonstrating innovation in ballet research. The findings provide important clinical information which may help develop the understanding of injury occurrence. Utilising laboratory- and field-based monitoring techniques in a ballet context may better inform clinical practice in training prescription towards reducing injury.

Date of Award	21 Jun 2021
Original language	English
Awarding Institution	Edge Hill University
Supervisor	MATT GREIG (Director of Studies) & CHRISTOPHER BROGDEN (Supervisor)