Optimization is a useful method to study control in biomechanical systems. At the same time the optimization limits and requires consideration of computational cost, degrees of freedom and sensitivity of constraints. Here the athletic long jump has been studied as a multibody system, seeking an optimal take-off technique. The model was based on rigid links, joint actuators and a wobbling mass. The contact to the ground was modelled as a spring-damper system with tuned properties. The movement in the degrees of freedom representing physical joints was described over contact time through two fifth-order polynomials, with a variable transition time, while the motion in the degrees of freedom of contact and wobbling mass was integrated forward in time, as a consequence. Muscle activation variables were then optimized in order to maximize ballistic flight distance. The optimization determined contact time, end configuration, activation and interaction with the ground from an initial configuration. The simulation used initial velocities from recorded jumps(Athens,Muraki) and anatomical data from referred experiments were complemented by assumed reasonable data. A sensitivity study was performed for important basic parameters. The results from optimization show a reasonable agreement with experimentally recorded jumps.