Computer Simulation of the Optimal Motion in Standing Long Jumps with Extra Weights

• Main Authors: Jheng-Chi Lee, 李政騏
• Other Authors: Kuangyou B. Cheng
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/31223212711213075266

碩士 === 國立成功大學 === 體育健康與休閒研究所 === 97 === The purpose of this study is to investigate how and why holding extra weight affects standing long jump performance. Two phases, including the preflight and flight phases, are simulated in this study. The model consists of five segments (feet, shanks, thighs, head and trunk, and arms) connected by four frictionless joints. All the joints could actively flex, extend, and relax. This five-segment model is to simulate the preflight phase. And after jump takeoff, the human body is modeled as a particle in the flight phase. In the preflight phase, model movements start from the same starting position which is a static standing posture without extra weights on hands (actually the wrist joint). Next, point weights ranging from 0 to 10 kilograms are fixed on hands to simulate standing long jumps. The objective function is the horizontal distance between the center of mass at landing and toe position before takeoff. From kinetic and kinematic analysis, it is found that the relationship between extra weights and performances is close to a quadratic function. Better jumping performance is achieved when the extra weight is between 5 and 8 kilograms. It is concluded that the mechanism of improved performance is caused by generating greater joint torque with appropriate extra weight.