Optimization of Long Jump Landing Motion using Musculoskeletal System Simulation

Biomechanical modeling of the musculoskeletal system has become an important issue in human motion analysis. The scope of this paper is focused on the optimization of long jump landing using musculoskeletal system. In the long jump, athletes are affected by the dynamics of the sand pit that is different from a hard surface in the landing phase. Therefore, in order to obtain a good landing motion, it is necessary to analyze the dynamics of the sand and athlete simultaneously. The aim of this study is to obtain an optimal landing motion in the long jump by Multi-Objective Genetic Algorithm using a long jump model. This simulation model is composed of two elements, which are a musculoskeletal model and a landing pit model. The human body model is based on a multi body model containing eight rigid links and nineteen Hill-type muscles. The sand pit is modeled as particles assembly. Generally, it is very time-consuming to calculate an optimal motion and a particle calculation. Here, this paper proposed a floating sand pit model which is suited to the optimization of the landing motion. As examples, we performed two optimization problems which have different objective functions, and compared with each other.