| Research objective: through the sports biomechanics research,the author analyzed the four difficulty element of group A(Group A:dynamic strength difficulty),so as to find out the technical differences of athletes,extract high-quality technology,and provide technical support for coaches and athletes.The subjects of this study were 15 middle school aerobics athletes,including 7boys and 8 girls.Among them,5 were Master Sportsman,2 were first-level athletes,and the rest were second-level athletes.Their average age was 15.6 1.5 years,their height was 160.9 8.39 cm,their weight was 50.07 ±10.48 kg,and their training years were 5.3± 2.28 years.Research content: A-frame(A184),A-frame with Wenson(A185),1/2 twist A-frame(A186),1/2 twist A-frame with Wenson push-up(A187).Research methods: Simi-motion kinematics analysis system and Footscan force measurement system were used to catch the data synchronously.Through the analysis of video and pressure data,indexes such as the change of major joint angles,joint movement speed,height of center of gravity and ground pressure were collected in each stage,and their completion was analyzed to find out existing problems and laws,so as to provide theoretical support and training Suggestions for athletes and coaches.Results: 1.In the A184 difficult movements,the maximum elbow Angle(landing Angle)of the male athletes is larger than that of the male athletes.Male students have more depth of brace than female students in the descending stage of arm flexion.Boys do shoulder joint "up" type of push-ups,girls do "T" type of push-ups;The maximum Angle of hip joint of male athletes on the ground is greater than that of female athletes.Elite athletes have better hip extension than secondary athletes.The control of knee and ankle joint of male athletes is weaker than that of female athletes.The pressure distribution of the athlete's palm to the ground is biased to one side,and the palm force is uneven.Boys pushed faster than girls,but there was no significant difference in height and time.2.In the A185 difficult movement,the knee joint of the middle and high level athletes of male athletes is more narrow.For female athletes,the minimum Angle of elbow joint is larger for the middle and high level athletes.The minimumAngle of shoulder joint of female middle and high level athletes is greater than that of the second level athletes.In the ground stage,the maximum Angle of the hip joint of male students is greater than that of female students.The minimum Angle of elbow joint of male students is smaller than that of female students.The Angle of shoulder joint is smaller when boys do push-ups.In the air stage,the control of knee and ankle joint is better for girls than for boys.The center of gravity of high-level athletes rises faster.3.Athletes with high level of A186 and A187 difficulty sports have larger rotation Angle;Part of the above two difficulty athletes rotation Angle is not enough because of the rise of the rotation Angle is not enough,with the shoulder to carry the buttock rotation technology is not well mastered,and the two difficulty in the hands of multiple off the ground at the same time,the landing situation,should be avoided.4.Difficulty A185 and A187 are all difficult movements with Vinson's leg technique.Vinson's thigh technique is divided into two types.The A187 difficulty is more suitable for the side swing leg in the process of rising in the air due to the need of descending rotation,providing assistance for the rotation.Conclusions and recommendations: 1,A184 difficulty movement,the main problems of the athlete's shoulder elbow control,different sports levels in the two joint Angle reflects the different technology,elbow and shoulder joint Angle is the key to judge prone,Suggestions to strengthen the standard push-ups in training and the strength exercises under the dynamic environment,avoid excessive use of compensatory straps power.2,A185 difficult moves,the athletes showed the most significant technology is characterized by Vincent points selection of leg techniques,this paper argues that: A185 leg technology difficulty of Vincent points should be chosen directly rather than side swing leg thigh,in the form of advice ascending lumbar abdomen athletes in training,improve the torso and legs of suspension Angle,and through repeated practice training athletes leg muscle memory.3.The difficulty of A186 and A187 in the push-over stage mainly focuses on the situation that both hands cannot leave the ground and fall to the ground at the same time.The training should focus on practice and attention to correction.A187 difficulty is all difficult movements with Vinson's leg technique.A187 difficulty is more suitable for side swing leg in the process of rising in the air to provide assistance for rotation due to the need of descending body rotation. |
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