Effects of a foot placement constraint on use of motor equivalence during human hopping.
Effects of a foot placement constraint on use of motor equivalence during human hopping.
复制标题
脚部放置限制对人类跳跃过程中运动量使用的使用的影响。
DOI：
10.1371/journal.pone.0069429
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Chang YH
中科院分区：
文献类型：
--
作者：
Auyang AG;Chang YH
人类可以在复杂的地形上稳健地移动，即使同时参加其他任务，如在地面上准确放置脚。我们调查了受试者是否会利用运动冗余的腿关节，以稳定整体肢体运动时，提出了一个跳跃的任务，限制脚的放置位置。受试者单腿跳到位（2.2 Hz），同时必须在着陆时将其脚放入三个目标尺寸之一中（0.250、0.063、0.010 m2）。由于起飞和着陆角度对这项任务的执行至关重要，我们假设较小的目标尺寸将增加稳定的需要（即，使更一致）通过分段角度的运动等效组合来实现腿的定向。由于其对靶向任务并不关键，我们假设在靶尺寸范围内下肢长度稳定性没有变化。对于较小的目标尺寸，我们看到总节段角度方差增加，这是由于与腿部伸肌（内侧和外侧腓肠肌、股内侧肌、股外侧肌和股直肌）激活增加相关的更大的信号依赖性噪声。在较小的目标尺寸下，更多的节段角度变化与运动学偏差对齐，目的是保持腿部方向轨迹。我们还观察到在最小目标条件下稳定腿长的方差结构减少。这种权衡效应是由腿长与腿方向稳定的两个目标等效流形之间的近正交关系来解释的。我们的研究结果表明，人类越来越多地依赖于他们的腿运动冗余，以实现强大的，一致的运动时，面对新的条件，限制性能要求。这些原理可以推广到其他人类运动步态，并为人类行走和跑步过程中腿部的控制提供重要见解。
Humans can robustly locomote over complex terrains even while simultaneously attending to other tasks such as accurate foot placement on the ground. We investigated whether subjects would exploit motor redundancy across the joints of the leg to stabilize overall limb kinematics when presented with a hopping task that constrained foot placement position. Subjects hopped in place on one leg (2.2 Hz) while having to place their foot into one of three target sizes upon landing (0.250, 0.063, 0.010 m2). As takeoff and landing angles are critical to this task performance, we hypothesized smaller target sizes would increase the need to stabilize (i.e., make more consistent) the leg orientation through motor equivalent combinations of segment angles. As it was not critical to the targeting task, we hypothesized no changes for leg length stabilization across target size. With smaller target sizes, we saw total segment angle variance increase due to greater signal-dependent noise associated with an increased activation of leg extensor muscles (medial and lateral gastrocnemius, vastus medialis, vastus lateralis and rectus femoris). At smaller target sizes, more segment angle variance was aligned to kinematic deviations with the goal of maintaining leg orientation trajectory. We also observed a decrease in the variance structure for stabilizing leg length at the smallest target conditions. This trade-off effect is explained by the nearly orthogonal relationship between the two goal-equivalent manifolds for leg length vs. leg orientation stabilization. Our results suggest humans increasingly rely on kinematic redundancy in their legs to achieve robust, consistent locomotion when faced with novel conditions that constrain performance requirements. These principles may generalize to other human locomotor gaits and provide important insights into the control of the legs during human walking and running.
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影响因子：
2.8
作者：
Chang, Young-Hui;Auyang, Arick G.;Nichols, T. Richard
通讯作者：
Nichols, T. Richard
影响因子：
2.4
作者：
BLICKHAN, R
通讯作者：
BLICKHAN, R
影响因子：
64.8
作者：
Harris, CM;Wolpert, DM
通讯作者：
Wolpert, DM
影响因子：
2.5
作者：
Ivanenko, Y. P.;d'Avella, A.;Lacquaniti, F.
通讯作者：
Lacquaniti, F.
影响因子：
2.4
作者：
Chang, Young-Hui;Roiz, Ronald A.;Auyang, Arick G.
通讯作者：
Auyang, Arick G.