Int J Sports Physiol Perform. 2018 Apr 1;13(4):420-427. doi: 10.1123/ijspp.2016-0812. Epub 2018 May 16.
Practitioners have, for many years, argued that athletic sprinters should optimize front-side mechanics (leg motions occurring in front of the extended line through the torso) and minimize back-side mechanics. This study aimed to investigate if variables related to front- and back-side mechanics can be distinguished from other previously highlighted kinematic variables (spatiotemporal variables and variables related to segment configuration and velocities at touchdown) in how they statistically predict performance. A total of 24 competitive sprinters (age: 23.1 [3.4] y, height: 1.81 [0.06] m, body mass: 75.7 [5.6] kg, and 100-m personal best: 10.86 [0.22] s) performed two 20-m starts from block and 2 to 3 flying sprints over 20 m. Kinematics were recorded in 3D using a motion tracking system with 21 cameras at a 250 Hz sampling rate. Several front- and back-side variables, including thigh (r = .64) and knee angle (r = .51) at lift-off and maximal thigh extension (r = .66), were largely correlated (P < .05) with accelerated running performance, and these variables displayed significantly higher correlations (P < .05) to accelerated running performance than nearly all the other analyzed variables. However, the relationship directions for most front- and back-side variables during accelerated running were opposite in comparison to how the theoretical concept has been described. Horizontal ankle velocity, contact time, and step rate displayed significantly higher correlation values to maximal velocity sprinting than the other variables (P < .05), and neither of the included front- and back-side variables were significantly associated with maximal velocity sprinting. Overall, the present findings did not support that front-side mechanics were crucial for sprint performance among the investigated sprinters.
多年来，从业者一直认为田径短跑运动员应优化前侧力学（躯干延伸线前方发生的腿部动作）并最小化后侧力学。本研究旨在探究前侧和后侧力学相关变量是否可以与其他先前强调的运动学变量（时空变量以及与触地时的肢体配置和速度相关的变量）区分开来，以及它们在统计上如何预测运动表现。共有 24 名竞技短跑运动员（年龄：23.1[3.4]岁，身高：1.81[0.06]米，体重：75.7[5.6]公斤，100 米个人最佳成绩：10.86[0.22]秒）从起跑器上进行了两次 20 米起跑和 2 到 3 次 20 米的飞行冲刺。使用具有 21 个摄像头的运动跟踪系统以 250 Hz 的采样率在 3D 中记录运动学。包括离地时和最大大腿伸展时的大腿（r=0.64）和膝盖角度（r=0.51）以及最大大腿伸展时的最大大腿伸展角度（r=0.66）在内的多个前侧和后侧变量与加速跑步性能高度相关（P<0.05），与加速跑步性能的相关性显著高于几乎所有其他分析变量（P<0.05）。然而，与理论概念相比，在加速跑步过程中，大多数前侧和后侧变量的关系方向相反。水平踝关节速度、接触时间和步频与最大速度冲刺的相关性显著高于其他变量（P<0.05），并且没有一个包含的前侧和后侧变量与最大速度冲刺显著相关。总的来说，本研究结果不支持前侧力学对所研究短跑运动员的短跑表现至关重要。
