The Biomechanical Analysis Of The Backhand Throwing Action Of Ultimate Frisbee

Ultimate Frisbee is a highly competitive and entertaining group sports project.It started late in China and belongs to a new sports project.In recent years,although the development of ultimate Frisbee sports in our country has begun to take shape,the level of competition is still far from that of developed countries,and it has become a clear short-board in the emerging competitive sports.The backhand throwing action is a technical means that the ultimate Frisbee athletes must have,and it is of certain practical value to master the technical action.The kinematics and kinetic parameters of the backhand throwing motion of three ultimate Frisbee athletes at Harbin Institute of Technology were obtained by means of three-dimensional camera and three-dimensional force measuring platform synchronization test.The purpose was to reveal the key of the action technology.It provides reference for relevant scholars and coaches engaged in the training and teaching of the project and has a greater role in promoting related scientific research and technological development.Kinematics uses two Quintic high-speed cameras to collect three-dimensional images of backhand throwing movements.The three-dimensional analysis system of The APAS System is used to analyze the kinematics parameters such as the angle,speed,and center of gravity displacement of each joint of the motion;Dynamics uses a Swiss Kistler force measuring platform to test the ground reaction forces in the X axis,Y axis,and Z axis directions of the subject's backhand throwing action.An analysis of the relevant data leads to the following conclusions:(1)From the point of view of time characteristics,the overall action time is 2.998±0.261 s,the lead stage is 1.146±0.128 s,the throw stage is 0.464±0.054 s,and the swing stage is 0.735±0.221 s.The end reduction stage is 0.653±0.0.174 s.(2)From the perspective of the characteristics of joint angle changes,the angle of each joint of the backhand throwing action conforms to the principle of the orderly movement of the human joints and the characteristics of the changes are significant.The angle of each joint of the upper limb of the throwing plate increases in turn,and there is no obvious regularity in each joint of the upper limb after the Frisbee shot.Individual differences are more obvious.(3)During the entire movement,the trunk is twisted twice.The distortion of the trunk is a comprehensive effect of muscle contraction.It can effectively maintain its own balance,accelerate the movement of the limbs,and lay the foundation for improving the stability and speed of the Frisbee.(4)The backhand throwing technique action is actually a whip action of the upper limb.Each link forms a chain of links.During the movement process,each link continuously accelerates and brakes to produce new impulse moments,and the momentum moments of the previous link are stacked and accumulated in turn.To maximize momentum at the end.(5)Athletes in the course of throwing the plate through the legs of the lower limbs,resulting in a greater ground reaction force,through the trunk and the coordination of various links,to increase the explosive force of the upper limbs.