Gantz Alyssa M, Derrick Timothy R
a Department of Kinesiology , Iowa State University , Ames , IA , USA.
J Sports Sci. 2018 May;36(10):1103-1110. doi: 10.1080/02640414.2017.1357829. Epub 2017 Jul 31.
The purpose of this study was to investigate the kinematic and metabolic effects of running on an irregular surface. We also examined how altering the frontal plane foot angle (inversion/eversion) at contact using real-time visual feedback would affect these other variables. Sixteen participants completed three running bouts lasting 5-7 minutes each on an irregular surface (IS) treadmill, a traditional smooth surface (SS) treadmill, and on SS while receiving visual feedback of the frontal plane foot angle at contact (SSF) with a goal of matching IS foot angle on SS. Frontal plane foot angle increased 40% from IS to SS (IS: 8.4 ± 4.09°, SS: 11.8 ± 4.52°, P < 0.0001, ES 1.40). Knee flexion angle at contact decreased 33% from IS to SS (IS: 9.2 ± 4.88°, SS: 6.2 ± 5.03°, P < 0.0001, ES 1.30). Rate of oxygen consumption decreased by 10% from IS to SS (IS: 37.9 ± 5.68 ml·kg·min, SS: 34.1 ± 5.07 ml·kg·min, P < 0.0001, ES 3.05). PSD of leg accelerations decreased by 38% (IS: 0.17 ± 0.07 g/Hz, SS: 0.106 ± 0.05 g/Hz, P < 0.000, ES 1.69). Frontal plane foot angle decreased by 14% from SS to SSF (SS: 11.8 ± 4.52°, SSF: 10.1 ± 4.42°, P = 0.027. ES 0.62) but did not result in significant changes in any other variables. There were no significant differences in shock attenuation between any conditions (IS: -9.8 ± 2.26 dB, SS: -9.5 ± 3.12 dB, SSF: -9.9 ± 2.62 dB, P = 0.671). Running with greater eversion on the irregular surface may be an attempt by runners to reduce the perceived potential of an inversion ankle sprain. As a partial compensation for the decreased foot angle, runners increased knee flexion. This maintained shock attenuation but increased the rate of oxygen consumption. Altering the foot angle at contact using feedback on the SS caused the knee angle at contact to increase, but did not change shock attenuation or metabolic cost.
本研究的目的是调查在不规则表面上跑步的运动学和代谢影响。我们还研究了使用实时视觉反馈改变着地时额面足角（内翻/外翻）如何影响这些其他变量。16名参与者在不规则表面（IS）跑步机、传统平滑表面（SS）跑步机上以及在SS上接受着地时额面足角的视觉反馈（SSF）的情况下，各完成了三次持续5 - 7分钟的跑步试验，目标是在SS上匹配IS的足角。从IS到SS，额面足角增加了40%（IS：8.4±4.09°，SS：11.8±4.52°，P<0.0001，效应量1.40）。着地时的膝关节屈曲角度从IS到SS减少了33%（IS：9.2±4.88°，SS：6.2±5.03°，P<0.0001，效应量1.30）。耗氧率从IS到SS下降了10%（IS：37.9±5.68毫升·千克·分钟，SS：34.1±5.07毫升·千克·分钟，P<0.0001，效应量3.05）。腿部加速度的功率谱密度下降了38%（IS：0.17±0.07克/赫兹，SS：0.106±0.05克/赫兹，P<0.000，效应量1.69）。从SS到SSF，额面足角下降了14%（SS：11.8±4.52°，SSF：10.1±4.42°，P = 0.027，效应量0.62），但并未导致任何其他变量的显著变化。在任何条件下，减震效果均无显著差异（IS：-9.8±2.26分贝，SS：-9.5±3.12分贝，SSF：-9.9±2.62分贝，P = 0.671）。在不规则表面上以更大的外翻角度跑步可能是跑步者试图降低感知到的内翻踝关节扭伤可能性的一种尝试。作为对足角减小的部分补偿，跑步者增加了膝关节屈曲。这维持了减震效果，但增加了耗氧率。在SS上使用反馈改变着地时的足角会导致着地时的膝关节角度增加，但并未改变减震效果或代谢成本。
