사이클링 선수의 슬관절각에 따른 하지동작의 운동학적 분석 = A Kinematical Analysis of the Leg Movements According to Cyclists` Joint Angles

다국어 초록 (Multilingual Abstract)

This study set out to evaluate the appropriateness of the height of a cycle saddle which was usually set based on a cyclist`s experience and simple judgment. For this purpose, there was aroused a need to study what a cyclist`s leg movements were according to the knee joint angle, that is, to study how a cyclist`s leg joint angles and angular velocity would change at each pedaling. Seven male college cyclists were selected, and their pedaling movements were divided into four phases. The images were taped at 60fields/sec, using two video cameras. The KWON 3D 2.1 program was adopted to calculate and synchronize the 3D coordinates values which were calculated with DLT(Direct Liner Transformation), in order to analyze kinematical factors. The results were as follows: 1) There was found no difference between foot joint angles according to changes of knee joint angles in each phase. But it became clear that Phase 1 and 2 where the foot angle got bigger were the area where the foot joint was expanded and that Phase 3 and 4 where the foot angle got smaller were the area where the foot joint was bent. Accordingly, the area which gives a great indirect impact to the changes of foot joint angles is considered to be the first part of Phase 3 at which point the cycle of pedaling starts. 2) In terms of the difference of foot joint angular velocity according to knee joint angles, there was found a relatively stable deceleration in the decelerating area(Phase 3 and 4) while you could detect faster changes in the acceleration area(Phase 1 and 2) than in the decelerating area. 3) The changes in the angle difference of knee joints according to each knee joint angle showed almost similar patterns for every knee joint. But the patterns had the graph model of the opposite shape to that of the angle difference of foot joints. 4) The research went on to see what kind of difference the knee joint angle made as knee joint angular velocity changed. The changes were unlike the foot joint angular velocity and thus showed relatively slow deceleration and acceleration. And the higher the saddle was set, the bigger the difference of the angular velocity was. 5) The difference of hip joint angles according to knee joint angles made a graph pattern which showed no big correlation with the height of a saddle. 6) In considering how hip joint angular velocity would change according to knee joint angles, the higher a saddle was set, the bigger angular velocity was found in Phase 1 and 2, the area of joint expansion and the smaller angular velocity in Phase 3 and 4, the area of joint bending. Comparisons and analysis were made based on the results above mentioned. The conclusion was that the lower a saddle which was one of the three experiment conditions was set, the smoother the pedaling turned and the bigger the angular velocity was resulted. In other words, when you take a long road cycling with your saddle fixed at a little lower height than the average one, you will consume less physical strength and expect better performance.