Biomechanical Analysis On The Waltz Reverse Turn And Slow Foxtrot Reverse Turn Of Elite Male Standard Dancer In China

Research purpose: In the standard dance,Waltz and Slow Foxtrot are very similar in vision as two swing slow dances,but there are differences in action requirements and dance style.Theoretically,the differences between Waltz and Slow Foxtrot can be traced,but there is no relevant data support.The analysis of the technical characteristics and style characteristics of the two dances has certain guiding significance for the technical correction of the standard dance.The purpose of this paper is to quantify the difference between Waltz’s reverse turn and Slow Foxtrot’s reverse turn from two aspects of kinematics and dynamics.In order to find out the key factors to distinguish Waltz and Slow Foxtrot,and provide theoretical basis for the training and teaching of standard dance.Research methods: This study analyzed the reverse turn step of four excellent standard dancers in China,and collected the kinematic and dynamic data of the reverse turn step synchronously by using the Qualisys infrared motion capture system and four Kistler three-dimensional force measuring platforms.Each subject was asked to follow the same music to complete the waltz reverse turn(the first three steps)and Slow Foxtrot reverse turn respectively.According to the movement process,the reverse turn step was divided into four stages: power storage stage —— pedal extension stage —— support and swing stage —— arrival stage.The average value ±standard deviation of the data obtained from the subjects was statistically analyzed,so as to compare the technology of the two movements Performance.The statistical significance level was p ≤ 0.05.Results: 1)The total time of Waltz’s reverse turn was 2.41 ± 0.30 seconds,while that of Slow Foxtrot’s reverse turn was 3.06 ± 0.14 seconds.There was no significant difference(P > 0.05)in the time of the first,third and fourth stages,and there was significant difference(P < 0.05)in the time of the second stage.2)There was no significant difference(P > 0.05)between the highest and lowest points of the two movements,but there was a significant difference(P < 0.05)between the two movements.In the different joint angles of Waltz reverse turn and Slow Foxtrot reverse turn,the hip,knee,ankle and shoulder joints all present different angles.3)Support swing stage is the high incidence stage of lower limb injury.In the early X-axis direction of the first three stages,the left supporting leg is mainly forward force,and the peak of forward force appears in the middle supporting stage.On the Y axis,the force of the left supporting leg of Waltz and Slow foxtrot in the first three stages is not large to the left or right,but in the swinging period,in order to produce a larger swinging effect,the direction of the force starts to turn sharply to the left,producing the peak of the force.The maximum vertical force of waltz to the ground on Z axis is 743.02 N.The maximum ground reaction force of Slow foxtrot is649.42 N.Conclusion: 1)The negative correlation coefficient shows that the center of gravity of Waltz reverse turn and Slow Foxtrot reverse turn are similar,and the shoulder joint angles of the two reverse turn steps are similar in the third stage.2)The time value distribution of Waltz reverse turn and Slow Foxtrot reverse turn shows different technical characteristics.In addition to the accumulation stage,the time distribution of the other three stages of Waltz reverse turn step was even,while that of the second stage of Slow Foxtrot reverse turn step was longer than that of the third and fourth stages.Therefore,it can be considered that the excellent male players in dealing with the reverse turn movement of Waltz and Slow Foxtrot show different technical styles by using different time distribution.3)The movement speed and joint work of Slow Foxtrot’s center of gravity are always earlier than that of waltz,but the fluctuation range is slightly smaller than that of Waltz.Waltz’s right support leg stretches more fully in the second stage.4)In the first stage,the angle of the shoulder joint of Waltz’s reverse turn step is small.In the second stage,the angle begins to increase,and continues to increase until the end,which indicates that the swing movement of Waltz’s reverse turn step is greatly affected by the leg’s pedaling and stretching.In the first stage,the angle of the shoulder joint of Slow Foxtrot’s reverse turn step presents a large angle,while in the second and third stages,it slowly increases,and in the fourth stage,it decreases,which indicates that the swing movement of Slow Foxtrot’s reverse turn step is affected by the upper limb Conversion has a big impact.