| Trampoline exercise is based on quality,difficulty,vacancy height and horizontal displacement.It requires 10 reversing actions on specific trampoline equipment and is subject to rules and competition regulations.The movement technique of the trampoline project refers to a reasonable method for completing the individual skill of the human body structure on the trampoline device,fully demonstrating the skill of the athlete,and effectively completing the single action,the combined action and the complete set of actions.In the international trampoline scoring rules from 2017 to 2020,in order to encourage trampoline athletes to develop difficult movements,the International Federation of Trampoline Technical Committee increased the difficulty of calculating the first set of preliminaries into four difficulty levels,objectively requiring athletes to master more difficult movements.The difficult value of the 12003 o action is 1.9 points.Introducing it into a complete set of actions can greatly improve the difficulty value of the set of movements,and make the athletes gain greater advantages in the difficulty of the game.This research takes advantage of literature data method,video analysis method,expert interview method,mathematical statistics method,comparative analysis method,quadrant analysis method and other research methods,with Olympic champion Dong Dong and World Championship champion,Gao Lei completed in four competitions in 12003 o as the research object,the movement explores the technical characteristics of the action,in order to improve the technical level of the two athletes to complete the action,and also provides reference for other athletes to learn the action.The research conclusions are as follows:(1)12003 o The action is divided into six stages: the take-off stage,the formation of the group posture stage,the maintenance of the body posture,the rollover stage,the exhibition stage,the straight-down stage,and thepreparation of the touch-net stage.(2)Take-off phase: 12003 o The action pressing time is longer than the net time.The closer the net angle is to 90°,the better the netting effect.The hip and knee angles at the lowest point of the net are gradually increased,and the hip angle is 137° to 171°.For 144° to 158°,the shoulder angle should be close to 180°,ready for the take-off arm.The off-grid angle is between 92°and 98°,which is close to vertical,indicating that the extension is sufficient and the motion technique is better.The off-grid instantaneous hip angle decreases,between 111° and 131°,the knee angle increases to nearly 180°,indicating that the netting stage is fully extended;the off-net instant torso angle is between 49° and 65°,and the torso angle is Smaller,it helps the body to rise up to get a higher movement height.(3)Forming the body posture stage: 12003 o The formation of the body posture time is 0.16s~0.20 s,in the formation of the body posture,the height of the body center of gravity is between 2.54 m and 2.89 m.The height of the center of gravity of Dong Dong is higher in the body posture,indicating that Dong Dong's effect in the vertical direction is more obvious;The instantaneous hip angle is 54°-63°,and the knee angle is 75°-95°.Dongdong's hip and knee angles are small,indicating that the body posture is tight and the flip radius is reduced.(4)Maintaining the body flip state: 12003 o The movement of the group is 0.50 s to 0.60 s.The two athletes have a hip angle of 42° to 60° in the free-flip stage,and the knee angle is 50°~81°,Dong Dong's hip and knee angles are small,indicating that Dong Dong's body posture is better,the flip radius is smaller;At the end of the group posture,the torso angle is360°+251°-360°+319°.The torso angle of Dong Dong's two matches is in the third quadrant.Gao Lei's is in the fourth quadrant,indicating Dong Dong's exhibition.The timing is earlier.(5)Stage of the exhibition: The exhibition time of the 12003 o movement is between 0.12 s and 0.24 s,and the angular velocity of the exhibition is 575.00°/s to 857.14°/s.The exhibition time of Gao Lei is shortand the angular velocity of the exhibition is fast.To provide sufficient time for the subsequent turning stage,Dong Dong's longer exhibition time is related to his tight body posture.Both athletes completed the exhibition at the highest point.At the end of the exhibition,the height of the body's center of gravity was 4.86 m to 5.18 m.At the end of the exhibition,the torso angle was720°~720°+13°.Both athletes were in the first The completion of the exhibition in one quadrant shows that the two athletes have better body-building techniques.(6)Maintaining the straight body falling stage: 12003 o The action of keeping the straight body falling time is 0.62 s to 0.70 s,the falling time is longer,and the falling effect is better;at the end of keeping the straight body falling,the torso angle is 720°+ 224°~720°+255°,the torso angle is in the third quadrant,indicating that two athletes have a hip flexion above the shoulder level,resulting in a technical deduction of 0.1 points.Gao Lei's knee angle is 163° in the second match,there is a knee bend phenomenon,resulting in a technical deduction of 0.1 points,the two athletes have a shoulder angle at the end of the straight body,but the shoulder angle is less than 90 °,did not cause technical deduction.(7)Ready to touch the net stage: 12003 o The preparation time of the action is between 0.20 s and 0.24 s.The instantaneous body center of gravity is between 0.92 m and 1.03 m,and the time for preparing the net is long.The gravity is height of the center of higher than the height of the mesh,indicating that the net is ready for the net;the hip angle is 106°~119°,the knee angle is 140°~157°,and the hip and knee angle are gradually smaller,which is better for the next movement.Preparation: the torso angle is between 720 ° + 305 ° ~ 720 ° + 321 °,the two athletes have a larger trunk angle,the upper body leans forward,increasing the stability of the action,laying the foundation for the next action.(8)The rotation time of the two athletes' 12003 o movements was different.Dong Dong began to rotate in the fourth quadrant,and Gao Lei began to rotate in the first quadrant.The two athletes were better at the 180°stage of the swivel movement.In the 360° stage of the swivel,the hip angle was 180°~218°.Dong Dong had a serious back arch in two competitions.Gao Lei was in the second match.There was a slight back arch phenomenon,which caused technical deduction;the 540° stage,the hip angle and the knee angle were both 180°,the straight body posture remained good,and the rotation was completed in the third quadrant,indicating The swivel is more adequate.(9)The physical center of gravity of the two athletes in the four competitions is close to the vertical movement,and the longitudinal displacement in the stage of forming the body posture,keeping the straight body falling and preparing for the touch-net phase is large;Gao Lei has a larger horizontal direction in the second competition.Displacement,this dues to the fact that the upper body is leaning forward more at the moment of the take-off phase,which causes the whole action to have certain instability.(10)12003 o Action From the action time structure,the two players' action time structure is more reasonable,and the action technique is more skilled.Due to the complexity of the movement technique,the proportion of the body is the largest,ranging from 30.39% to 33.02%.The formation stage of the group poses the smallest proportion,which is 7.62%~9.62%.The formation of the body poses faster and can be reduced.Small flip radius with less energy loss.Suggest:(1)Dong Dong used it for a long time in the exhibition stage.To speed up the speed of the exhibition body,the back arch phenomenon appeared in the 360° stage of the swivel,which caused the deduction of the movement technique.It should pay attention to maintaining the straight body posture for the rotation;At the end of the straight body drop,there is an error phenomenon that the hip is buckled early.The hands are not close to the body side.The straight body posture should be kept below the shoulder level,and the movement technique should be deducted.The knee angle at the stage of preparing the net should be larger.The body leans forward to maintain thestability of the movement.(2)Gao Lei should pay attention to controlling the torso angle when he leaves the net during the take-off phase,and increase the torso angle within a reasonable range to prevent the movement from being unstable due to the excessive torso angle;the body posture should be quickly tightened during the formation of the body posture.Decreasing the radius of the flip,reducing the hip and knee angles during the roll-over phase of the body posture so that the body is more tight;the slight back arch phenomenon occurs in the 360°stage of the body rotation,and care should be taken to maintain the straight body posture for turning.Keeping the straight body falling,the arms are not close to the body side,and the knee flexion and knees appear above the shoulder level,causing the action technique to deduct points.It should be noted that keeping the straight body posture below the shoulder horizontal position and then bending the hip for preparation The network is ready. |
PDF Full Text Request