目的:探讨钢架雪车运动员不同推橇阶段支撑期冲量特征与速度之间的关系.方法:使用Vicon三维运动捕捉系统和Kistler测力台,同步采集17名国家钢架雪车运动员推橇阶段的运动学(速度与制动期、推进期时长)和动力学参数(地面反作用力、冲量).结果:1)与第3步相比,推橇20 m处的制动期时长更长而推进期时长更短,制动力和垂直力峰值更大而推进力峰值更小,水平制动冲量更大而水平推进冲量、净水平冲量更小;2)在第3步和20 m处,水平推进冲量、净水平冲量与速度均呈强的正相关关系(r=0.650,r=0.624,r=0.615,r=0.850,P<0.01);垂直冲量与第3步速度呈强的正相关关系(r=0.662,P<0.01);水平制动冲量与推橇20 m处速度呈中度正相关关系(r=0.536,P<0.05).结论:对于我国优秀钢架雪车运动员来说,较大的推进冲量和净水平冲量对推橇阶段的速度极为重要,且在推橇加速阶段产生相对较大的垂直冲量可能更有利于提高推橇速度,但同时也不能忽视最大速度阶段制动冲量的作用.
Objective:To explore the relationship between impulse characteristics and velocity of the skeleton athletes during support period in different pushing phase.Methods:The Vicon three-dimensional motion capture system and Kistler force plate were used to simultaneously collect the kinematics(velocity,braking time,impulsive time)and dynamics parameters(ground reaction force,impulse)of 17 national skeleton athletes during pushing phase.Results:1)Compared with step 3,the braking time at 20 m was longer and the propulsive time was shorter,the peak braking force and vertical force were greater but the peak propulsive force was smaller,the horizontal braking impulse was larger but the horizontal propulsive and net horizontal was smaller;2)At step 3 and 20 m,the horizontal propulsive impulse,net horizontal impulse and velocity were strongly correlated(r=0.650,r=0.624,r=0.615,r= 0.850,P<0.01);the vertical impulse and the velocity of step 3 was correlated positively(r=0.662,P<0.01),and the horizontal braking impulse was positively correlated with the velocity at 20 m(r=0.536,P<0.05).Conclusions:For the high-level skeleton athletes,a large propulsive and net horizontal impulse are extremely important for push velocity,and it may be more beneficial to generate a relatively large vertical impulse during the acceleration push phase;meanwhile,the role of the braking impulse during the maximum speed phase should not be neglected.