Use Your Head! in Giant Circles on High Bar.

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Özgören N. Ş., Arıtan S.

Biomechanics of Human Motion Workshop, Güzelyurt, Cyprus (Kktc), 20 - 21 June 2015

  • Publication Type: Conference Paper / Summary Text
  • City: Güzelyurt
  • Country: Cyprus (Kktc)
  • Hacettepe University Affiliated: Yes


The aim of this study was to simulate characteristics of backward and forward giant circle on high bar. Input data for simulation was obtained from five former national gymnasts, which performed backward and forward giant circles on high bar. Simulation model was built using SimMechanics (version 4.4) libraries in SIMULINK (version 8.3). The model was driven by using joint torques that were calculated from the inverse dynamics simulation model. The performed simulations were started with the model fully extended in the handstand position and each simulation was started with an initial angular velocity. Three simulations were performed to investigate the role of head. In the first simulation, motion of the head was controlled with kinematic constraints and it was seen that the simulation model closely matches the actual performance of the gymnasts only with a small decrease in angular velocity in body’s centre of gravity. In the second simulation the angular position of the head was fixed at 20 degrees with respect to the position of the arm. While the model completed 360° rotation around the bar and the angular velocity of the body’s centre of gravity was very close to the actual performance, abrupt changes in knee, and shoulder and hip angles after the lowest point of the action. In the third and the last simulation, head was neglected and the model was run without head. However the model managed to complete the whole rotation around the bar slower than the first two simulations, there were huge angular changes in the shoulder, hip and knee joints which exceeds the actual performance. As a consequence the gymnast over-extended at the highest point and the velocity of the body was reduced while passing through the lowest point in the third simulation. In conclusion it was found that the head segment has an important role in the control of the rotating whole body system during the giant circles.