Girard O, Brocherie F, Tomazin K, Farooq A, Morin J-B
ISSUL, Institute of Sport Sciences, Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Switzerland.
University of Ljubljana, Faculty of Sport, Ljubljana, Slovenia.
J Biomech. 2016 Jun 14;49(9):1490-1497. doi: 10.1016/j.jbiomech.2016.03.020. Epub 2016 Mar 19.
Compare alterations in running mechanics during maximal treadmill sprints of different distances.
Eleven physically active males performed short (100-m), medium (200-m) and long (400-m) running sprints on an instrumented treadmill. Continuous measurement of running kinetics/kinematics and spring-mass characteristics were recorded and values subsequently averaged over every 50-m distance intervals for comparison.
Compared with the initial 50m, running velocity decreased (P<0.001) by 8±2%, 20±4% and 39±7% at the end of the 100, 200 and 400-m, respectively. All sprint distances (except for step length in the 100-m) induced significantly longer (P<0.05) contact times (+7±4%, +22±8% and +36±13%) and lower step lengths (-1±4%, -5±5% and -41±2%) and frequencies (-6±3%, -13±7% and -22±8%) at the end of the 100-m, 200-m and 400-m, respectively. Larger reductions in ground reaction forces occurred in horizontal versus vertical direction, with greater changes with increasing sprinting distance (P<0.05). Similarly, the magnitude of decrement in vertical stiffness increased with sprint distance (P<0.05), while leg stiffness decreases were smaller and limited to 200-m and 400-m runs. Overall, we observed earlier and larger alterations for the 400-m compared with other distances.
The magnitude of changes in running velocity and mechanics over short (100-m), medium (200-m) and long (400-m) treadmill sprints increases with sprint distance. The alterations in stride mechanics occur relatively earlier during the 400-m compared with the 100-m and 200-m runs.
比较不同距离的最大速度跑步机冲刺跑过程中跑步力学的变化。
11名身体活跃的男性在装有仪器的跑步机上进行短距离（100米）、中距离（200米）和长距离（400米）的跑步冲刺。连续测量跑步动力学/运动学和弹簧质量特性，并随后对每50米距离区间的值进行平均以作比较。
与最初的50米相比，在100米、200米和400米冲刺结束时，跑步速度分别下降了8±2%、20±4%和39±7%（P<0.001）。所有冲刺距离（100米的步长除外）在100米、200米和400米冲刺结束时分别导致显著更长的（P<0.05）接触时间（增加7±4%、22±8%和36±13%）以及更小的步长（减少1±4%、5±5%和41±2%）和步频（减少6±3%、13±7%和22±8%）。地面反作用力在水平方向的下降幅度大于垂直方向，且随着冲刺距离增加变化更大（P<0.05）。同样，垂直刚度的下降幅度随冲刺距离增加（P<0.05），而腿部刚度的下降较小且仅限于200米和400米跑。总体而言，与其他距离相比，我们观察到400米跑的变化更早且更大。
在短距离（100米）、中距离（200米）和长距离（400米）跑步机冲刺跑过程中，跑步速度和力学的变化幅度随冲刺距离增加。与100米和200米跑相比，400米跑的步幅力学变化相对更早出现。
