Research Biomechanics, Otto Bock HealthCare GmbH, Hermann-Rein-Str. 2a, 37075 Göttingen, Germany; Motionscience, Institute of Sport Sciences, Friedrich Schiller University Jena, Seidelstraße 20, 07749 Jena, Germany.
Motionscience, Institute of Sport Sciences, Friedrich Schiller University Jena, Seidelstraße 20, 07749 Jena, Germany.
J Biomech. 2019 Feb 14;84:278-283. doi: 10.1016/j.jbiomech.2018.12.036. Epub 2018 Dec 31.
In running, humans use different control strategies that are most likely influenced by environmental conditions. For example, when human runners face a change in ground level, they adapt the height of their center of mass (CoM) in preparation. In a situation in which a drop might occur but without visual cues regarding its actual height, such a preparation is not possible. We here used camouflaged drops (which occurred by chance) as mechanical disturbances and analyzed the adaptations in the vertical oscillation of the runners CoM. We found that humans lowered their CoM by about 25% of the possible drop height in preparation for the camouflaged contact, regardless of whether a drop occurred or not. In flight phase following the disturbance, the CoM was lowered by about 90% of the drop height in the case of the camouflaged drop and remained almost unaffected (+5%) in the case of level ground. Thus, runners resort to a CoM-control strategy with a fixed desired trajectory height in the flight phase following the camouflaged ground contact. In contrast to previously reported results which show that visible ground level changes were compensated within several steps, this strategy compensates ground level disturbances instantly within a single step.
在跑步中，人类使用不同的控制策略，这些策略很可能受到环境条件的影响。例如，当人类跑步者面临地面水平的变化时，他们会调整质心（CoM）的高度以作准备。在可能发生但没有关于实际高度的视觉线索的情况下，这种准备是不可能的。我们在这里使用伪装的下降（随机发生）作为机械干扰，并分析跑步者 CoM 的垂直振动的适应性。我们发现，人类会将 CoM 降低约 25%的可能下降高度，为伪装的接触做准备，无论是否发生下降。在受到干扰后的飞行阶段，CoM 在伪装下降的情况下会降低约 90%的下降高度，而在水平地面的情况下几乎不受影响（+5%）。因此，跑步者在伪装地面接触后的飞行阶段采用了一种 CoM 控制策略，其固定的期望轨迹高度。与之前报道的结果不同，这些结果表明可见的地面水平变化会在几个步骤内得到补偿，而这种策略会在单个步骤内即时补偿地面水平干扰。
