Biomechanical Study On The Effect Of Swing-Arm Movement For Swimming Start Of National Elite Swimmers

Research Purpose:The purpose of this study is to study the common start and swing-arm-start movements.This study combines motion biomechanical parameters to analyze the effects of swinging arm movements on the effects of start and lower leg kicking,and the effects of swinging arm movements on the start,take-off,air movement,and movement after entering water.Research Method:The subjects of this study were 8 elite swimmers.Kistler starting technology detection system was used to obtain relevant biomechanical parameters.Using Kpass and Dartfish 9.0 software to analyze the video recording to obtain relevant kinematic parameters.Before the experiment,eight athletes started their start for testing,followed by an eight-week technical teaching,and then post-tested the swing-arm start.Results:There were significant differences between the two squat-style starting movements at 5m,10m,and 15m(p<0.05).The average swimming start time of 5 meters is significantly related to average power,work,average acceleration,horizontal kick speed,average kick speed,average water speed,and water distance(p<0.05).The first time of kicking after entering the water was significantly correlated with the time of starting 7.5 meters and the time of 15 meters(p<0.05).The 5m time of the start with arm swing was significantly correlated with average power,peak horizontal force,work,average acceleration,horizontal kick speed,average kick speed,average water speed and water distance(p<0.05).There was no significant difference between the two squat squats in the initial movement time of the preparation phase(p>0.05);there was no significant difference in the angles of the shoulder,hip,knee,and ankle joints in the preparation posture(p<0.05).The average acceleration of two squat-style starting actions during the off-stage stage,the horizontal kick-off speed,the average kick-off speed,the average power,the peak power,the combined force average,the horizontal force peak,the thrust average,the thrust peak,and the front pedal plate combined force The peak force and mean value of the combined force of the rear pedal plate were significantly different(p<0.05).There were significant differences in shoulder amplitude and angular velocity,hind leg ankle joint angular velocity,hind leg knee joint angular velocity,hind leg hip joint amplitude and velocity,foreleg knee joint angular velocity,and hip angle at the time of departure(p<0.05).Research conclusion:(1)The swinging arm can improve the 5m time and 15m time of swimming start of high-level swimmers,but the starting time of 5m to 15m is the water glide action phase,and the time change at this stage is caused by the speed of the underwater leg.Thus,it cannot be inferred that swinging arm movement had a direct impact on the 15-meter departure.(2)The swinging arm has no effect on the starting position and the reaction time.The athlete does not need to make any adjustments to the prepare position of swimming start.(3)The force of the lower limbs on the starting platform is the main factor that affects the effect of 5 meters of swimming.The swinging arm action helps to increase the explosive force of the lower limbs when leaving the platform and the kicking speed in the horizontal direction when leaving the platform.Improve the take-off effect of squat start.(4)The swinging arm only affects the force and speed of the high-level athlete’s squatting starting stage and the distance of entering the water.There is no significant change in the emptying time under the condition of increasing the distance of entering the water.