A MODEL BASED COMPUTATIONAL APPROACH TO HUMAN VERTICAL JUMPING

A subject specific forward dynamic 3-actuator torque-driven model of the human musculoskeletal system was created, based on measure- ments of individual subject characteristics. The goal was to simu- late a common strength exercise: squat jump with and without extra load. Hip, knee and ankle resultant net torques were modeled from experimental data. Elastic components were not considered. Two models were created for each joint, and then implemented into sim- ulations. Subsequently they were compared to each other to estab- lished which one best matched actual performances. By analyzing kinematic and kinetic experimental data at the instant of the toe-off, it was shown that accurate joint torque models implemented in a sim- ple computer simulation could reproduce squat jumps. The model that best matched actual jumps was used to optimize jump height performance with and without extra load. A linear decreasing of the jump height was found as the load increased. The load at which the model would not be able to take-off was predicted. In addition, joint and global power outputs for different extra load conditions were es- timated. It seemed that global power output probably suffered from a slight inaccuracy of simulated vertical ground reaction forces. It was concluded that a computational approach combined with exper- imental data, is an original way to conduct research in strength and conditioning training. It would help coaches, athletes and scientists to better understand human performances. This investigation is the first step in a wider project aiming to evaluate the advantages of the individual subject approach for understanding strength exercise tasks.