Study On The Touching Technical Movement Characteristics And Application Of Performance Coaching In Chinese Trampoline Athletes

Objective: The more efficient the use of the touching technical movements by athletes,the better the net surface response,the more beneficial it is to the height of the air and the air technical performance.Therefore,the purpose of this study is to explore the dynamic and kinematic characteristics of the technical movements of trampoline athletes during the net touching stage,and analyze the movement patterns,joint activities and muscle force characteristics during the net touching stage.Develop a performance coaching program for trampoline athletes with Chinese characteristics.Through the preparation practice of Tokyo Olympic Games to verify the effectiveness of the program,to improve the performance of trampoline athletes,reduce the incidence of sports injuries to provide a scientific basis for the preparation of Paris Olympic Games to provide training reference and theoretical support.Methods: By using the methods of literature review,expert interview,testing and mathematical statistics,this research studies the characteristics of trampoline net touching technical movement and the performance coaching of trampoline for Chinese athletes.(1)Six athletes of Shanxi trampoline team were selected as the research objects to conduct movement capture and musculoskeletal modeling in the net touching stage,and analyze the movement mode and body force characteristics in the net touching stage.(2)Thirteen athletes of the national trampoline team were selected as the research objects.Use the electromyography system to obtain the characteristics of muscle force during the net touching stage,understand the athlete’s body balance characteristics through plantar pressure,and master the athlete’s body functional movement characteristics through FMS,YBT,and other tests.(3)A system of performance coaching methods with trampoline features was formed based on the technical features of touching the net and the functional movement characteristics of athletes.Through the preparation experience of Tokyo Olympic Games,Olympic champion Dong Dong was trained and interfered with the performance coaching to verify the effectiveness of the training program.Results:(1)Through the analysis of movement capture and musculoskeletal modeling,it is found that the speed of the center of gravity off the net is highly correlated with the height of the trampoline athletes’ jumping(p<0.01).The faster the speed off the net,the higher the jumping height of trampoline athletes.The peak reaction force on the body of elite male trampoline athletes during the net contact stage is 12.3 times their own weight on average,while female athletes are slightly lower than male athletes by 10.8 times.The peak reaction force on the body of first-class athletes is significantly lower than that of elite athletes,with 9.1 times for male athletes and 8.6 times for female athletes.(2)Through the EMG and plantar pressure tests,it was found that the quadriceps femoris muscle was an important force generating muscle group during the trampoline athletes’ contact with the net.There were differences in the left and right sides of trampoline athletes and their balance ability.The balance degree of the left and right sides of the lower limbs of female athletes was better than that of male athletes.(3)Through functional movement testing,it was found that trampoline athletes have insufficient hip joint flexion and ankle joint dorsiflexion functions,resulting in imbalanced muscle strength in the anterior and posterior muscles of the lower limbs;The upper limb strength level of female athletes is significantly lower than that of the lower limbs,while the stability of the left lower limb of male athletes is better than that of the right side.(4)Through 38 weeks of performance coaching intervention on Dong Dong,it was found that the indicators of functional movement screen showed a trend of improvement in the basic winter training period and a decrease in the specialized and competition periods;Athletes’ athletic abilities exhibit characteristics of ―acquisition,maintenance,and regression‖.(5)Performance coaching has a significant effect on the decline of physical ability caused by age in trampoline athletes.Performance coaching plays different roles in different training cycles.For trampoline athletes with physical dysfunction,the early stage of systematic training should be dominated by functional correction training.Sports injury prevention training can effectively regulate the imbalance and asymmetry of athletes’ bodies.As the preparation time deepens,basic and specialized performance coaching gradually becomes the main focus.(6)Integrating performance coaching with warm-up activities to form an all-day performance coaching mode plays an important role in preventing sports injuries for trampoline athletes.Conclusion:(1)There are differences in the movement modes of trampoline athletes’ net touching techniques.In the buffering stage,male athletes have a wide distance between their feet,with their body center of gravity leaning to the left,while female athletes have a narrow distance between their feet;In the stage of net pressing,athletes choose different timing for net pressing based on their respective strength levels.Lower limb strength is small,the timing for net is earlier;During the net lifting stage,the high load rebound of the net surface leads to passive bending of the hip joint,which reduces the efficiency of the athlete’s power chain transmission and affects the jumping height.(2)There are differences in the force characteristics of net touching techniques among trampoline athletes of different genders.The force characteristic of the net touching technique in trampoline athletes is that the activation of the posterior muscles of the lower extremity is relatively delayed,while the activation of the anterior muscles is relatively early.In the stage of touching the net,the lower extremity strength of male athletes is good,the distance between the feet is wide,the main functions of the lower limbs are different,the left lower limb is the main support side,the right lower limb is the main force side.The support side and force side of female athletes are mainly the right side,and the lower extremity force of female athletes is more balanced than that of male athletes.(3)Long term specialized training of trampoline athletes leads to specialized features in their athletic function.There is an imbalance in the athletic function of athletes,especially among male athletes.Performance coaching should control the imbalance and asymmetry of the lower extremity of trampoline athletes in a safe range,and the ratio of knee flexion and extension muscles should be between 42% and 67%,which is ideal.(4)Trampoline athletes should pay attention to the maximum strength of lower extremity,strength speed and explosive force in the performance coaching.Maximum Strength training can help athletes improve their ability to resist the high load resilience of the net during the lifting phase,and fast strength and explosive force training can help athletes maximize the power output at the appropriate time of pressing.The unilateral lower extremity strength training of male athletes plays an important role in promoting the unbalanced and asymmetric characteristics of the technical movements of net touching.The explosive training that transforms from static to dynamic(such as high clean,high snatch,etc.)and ballistictraining are more consistent with the special characteristics of trampoline;The lower extremity strength training should pay attention to strength speed and fast eccentric strength training.