Study On The Impact Of Towing Resistance Running In Different Attachment Positions On The Third Step Of Sprint Acceleration

Objective: Towing resistance sled running is an important means to develop acceleration ability,the training method is widely used in different projects,sprint training is also often used in the start-up acceleration running stage,used to develop the start-up acceleration ability.At present,the research of more drag resistance sled running focuses on the load measurement,the research on the body attachment position is less,the influence factor of drag resistance sled of different body attachment positions on the speed running technology is not clear.The purpose of this study is to explore the impact of drag resistance sled dies in different body attachment positions on the angle of the lower limb joints,the condition of force and the state of muscle activation of the sprint acceleration,and then explore sledding in which body attachment positions are beneficial to the development of acceleration ability,but also have less negative impact on the technique of short-sprinting acceleration running.Provide theoretical reference for short-sprinting training practice.Methods: The subjects of this experiment were 13 male sprinters,of whom 6were first-class athletes and 7 were second-level athletes.Experiment 1: The weight of the drag sled is determined based on the drag resistance sled running speed not exceeding 10%(10% Vdec)of the maximum speed of the weightless acceleration run.Experiment 2: Using 10% Vdec resistance sled weight,explore the shoulder,waist,shoulder-waist drag resistance sled running on the accelerated running technology.Simultaneous acquisition of kinematic,kinetic,and electromyography data using motion infrared high-speed motion capture system,Kistler 3D dyer,Delsys Trigno 16 guided portable wireless telemetry surface myoelectric test system.Using Cortex to calculate the lower limb joint angle,torque and work,Delsys EMGworks Analysis4.0 calculated the upper limb muscle square root amplitude.The SPARS21.0 software is used to perform a single-factor repeated measurement of avariance analysis.Results : Basic space-time parameters: three drag resistance sled running center of gravity horizontal speed is lower than the weightless acceleration of about 10%.The support period of the three drag resistance sled runs and the third-step ground distance are higher than the weightless acceleration run,of which the shoulder-waist drag resistance sled run is the third step of the largest ground distance.Joint angle: the three drag resistance sled running on the ground angle is less than the weightless acceleration run,of which shoulder-waist drag resistance sled running the smallest;When the three drag resistance sleds run to the ground,the knee angle is less than the weightless acceleration run,shoulder-waist drag resistance sled runs away from the ground at the moment the knee joint angle is the largest.Three kinds of drag resistance sled sled running to the ground,away from the front of the torso is less than the weightless acceleration run,in which the front angle of the torso from the ground drag resistance run less than the waist.Ground reaction force aspect: three kinds of drag resistance sled running horizontal braking power,braking impulse is less than no weight-bearing acceleration run,of which shoulder-waist drag resistance sled running the smallest.Reverse dynamics: the support stage hip mainly do negative work,drag resistance sled running to increase the hip negative work.In terms of amtaelectrics: the activation degree of hip muscle sled running during braking period and propulsion period is higher than that of the weightless acceleration run,and the activation degree of the straight muscle of the three drag resistance sled runs during the propulsion period is higher than that of the non-weight-bearing acceleration run.Conclusion:(1)10% Vdec load weight of shoulder,waist,shoulder-waist drag resistance sled running,all help to reduce the sprint acceleration run the third step of the ground braking,of which shoulder-waist drag drag resistance sled run is the most obvious reduction.(2)10% Vdec load weight of the shoulder,waist,shoulder-waist drag resistance sled run,all make the sprint speed running the third step of the extension more full,the front swing more active,in which the shoulder-waist drag resistance sled run the most full.(3)10% Vdec load weight of three different body attachment positiondrag resistance sled run makes hip extension muscle group centrifugal contraction increase,hip muscle muscle and straight muscle activation degree increased,muscle activation effect in line with the short-sand acceleration stage muscle force requirements,help to develop hip muscle and straight muscle strength quality.