Optimisation of performance in the triple jump using computer simulation

While experimental studies can provide information on what athletes are doing, they are not suited to determining what they should be doing in order to improve their performance. The aim of this study was to develop a realistic computer simulation model of triple jumping in order to investigate optimum technique. A 13-segment subject-specific torque-driven computer simulation model of triple jumping was developed, with wobbling masses within the shank, thigh, and torso. Torque generators were situated at each hip, shoulder, knee, ankle, and ball joint. Kinetic and kinematic data were collected from a triple jump using a force plate and a Vicon motion analysis system. Strength characteristics were measured using an isovelocity dynamometer from which torque-angle and torque-angular velocity relationships were calculated. Segmental inertia parameters were calculated from anthropometric measurements. Viscoelastic parameters were obtained by matching an angle-driven model to performance data for each phase, and a common set for the three contact phases was determined. The torque-driven model was matched to performance data for each phase individually by varying torque generator activation timings using a genetic algorithm. The matching produced a close agreement between simulation and performance, with differences of 3.8%, 2.7%, and 3.1% for the hop, step, and jump phases respectively. The model showed good correspondence with performance data, demonstrating sufficient complexity for subsequent optimisation of performance. Each phase was optimised for jump distance with penalties for excessive angular momentum at take-off. Optimisation of each phase produced an increase in jump distance from the matched simulations of 3.3%, 11.1%, and 8.2% for the hop, step, and jump respectively. The optimised technique showed a symmetrical shoulder flexion consistent with that employed by elite performers. The effects of increasing strength and neglecting angular momentum constraints were then investigated. Increasing strength was shown to improve performance, and angular momentum constraints were proven to be necessary in order to reproduce realistic performances.