Abstract
Gymnasts use a special movement pattern for particular long swing movements to gain optimum elastic energy of parallel bars to complete long swing movements artistically. Therefore it is essential to study body dynamics as well as the dynamic properties of exercise apparatus to minimize the execution errors. In the present study, performance of long swing movement under the parallel bars by national level gymnast of China (mass 50.4 kg) were evaluated. The time history of middle points of wooden bars and all joint angles were measured using a system of ten high speed cameras (100 Hz). The ViconT40 digitizing software was used to find all coordinates of reflective markers (14 mm) which were attached on parallel bar-gymnast system. Based on the overall readings, a 3D mathematical model for the parallel bars apparatus was developed using four damped spring-mass model (Kx = 28601 N.m-1, KY = 10830 and KZ = 19101 N.m-1) with linear displacement-force characteristics. A gymnast (50.4 kg) applied maximum horizontal force (Fx=584 N) to perform `long swing double tucked saltos' to upper arm support on the parallel bars. In this time, the particular vertical force (Fz) and arm angle (a) with X-axis are 488 N and 730 3' respectively. This 3D model can demonstrate dynamic properties of the parallel bars interacting with any long swing movement for any gymnast.