Swing-leg trajectory of running guinea fowl suggests task-level priority of force regulation rather than disturbance rejection.
Swing-leg trajectory of running guinea fowl suggests task-level priority of force regulation rather than disturbance rejection.
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DOI：
10.1371/journal.pone.0100399
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发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
Daley MA
中科院分区：
文献类型：
--
作者：
Blum Y;Vejdani HR;Birn-Jeffery AV;Hubicki CM;Hurst JW;Daley MA
为了在不平坦的地形中实现稳健和稳定的腿部运动，动物必须有效地协调肢体摆动和站立阶段，这涉及到不同但耦合的动力学。最近的理论研究强调了摆动腿轨迹对稳定性、抗干扰性、腿部负载以及步行和跑步的经济性的关键影响。然而，模拟表明，并非所有这些因素都可以同时优化。一个潜在的权衡之间出现的最佳摆动腿轨迹的干扰拒绝（保持稳定的步态）与调节腿部负载（避免伤害和经济）。在这里，我们调查如何运行珍珠鸡管理这种潜在的权衡比较实验数据的预测基于假设的模拟运行的地形下降扰动。我们使用一个简单的模型来预测摆动腿的轨迹和运行动力学。在模拟中，我们根据任务级控制优先级的特定假设生成优化的摆腿轨迹。我们优化了摆动轨迹，以实现i）恒定的峰值力，ii）恒定的轴向脉冲，或iii）在地形下降后的姿态中完美的干扰抑制（稳定步态）。我们比较模拟预测的实验数据，珍珠鸡运行在一个可见的步骤。运行珍珠鸡的摆动和站立动力学密切匹配模拟优化调节腿负载（优先级i和ii），并不匹配模拟优化干扰抑制（优先级iii）。模拟结果加强了以前的研究结果，摆腿轨迹目标干扰抑制要求大幅增加站立腿力以下的地形下降。珍珠鸡通过向前加速度的不稳定动力学向下一步，并在随后的步骤中恢复到稳定的步态。我们的研究结果表明，珍珠鸡使用摆动腿的轨迹与优先的负载调节一致，而不是稳定的步态。在不平坦的地形中，为负载调节而优化的摆动腿轨迹可以促进经济性和避免伤害。
To achieve robust and stable legged locomotion in uneven terrain, animals must effectively coordinate limb swing and stance phases, which involve distinct yet coupled dynamics. Recent theoretical studies have highlighted the critical influence of swing-leg trajectory on stability, disturbance rejection, leg loading and economy of walking and running. Yet, simulations suggest that not all these factors can be simultaneously optimized. A potential trade-off arises between the optimal swing-leg trajectory for disturbance rejection (to maintain steady gait) versus regulation of leg loading (for injury avoidance and economy). Here we investigate how running guinea fowl manage this potential trade-off by comparing experimental data to predictions of hypothesis-based simulations of running over a terrain drop perturbation. We use a simple model to predict swing-leg trajectory and running dynamics. In simulations, we generate optimized swing-leg trajectories based upon specific hypotheses for task-level control priorities. We optimized swing trajectories to achieve i) constant peak force, ii) constant axial impulse, or iii) perfect disturbance rejection (steady gait) in the stance following a terrain drop. We compare simulation predictions to experimental data on guinea fowl running over a visible step down. Swing and stance dynamics of running guinea fowl closely match simulations optimized to regulate leg loading (priorities i and ii), and do not match the simulations optimized for disturbance rejection (priority iii). The simulations reinforce previous findings that swing-leg trajectory targeting disturbance rejection demands large increases in stance leg force following a terrain drop. Guinea fowl negotiate a downward step using unsteady dynamics with forward acceleration, and recover to steady gait in subsequent steps. Our results suggest that guinea fowl use swing-leg trajectory consistent with priority for load regulation, and not for steadiness of gait. Swing-leg trajectory optimized for load regulation may facilitate economy and injury avoidance in uneven terrain.
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影响因子：
2.4
作者：
BLICKHAN, R
通讯作者：
BLICKHAN, R
影响因子：
2.2
作者：
DOW, SM;LEENDERTZ, JA;GOODSHIP, AE
通讯作者：
GOODSHIP, AE
影响因子：
56.9
作者：
BIEWENER, AA
通讯作者：
BIEWENER, AA
DOI：
10.1098/rstb.2010.0338
发表时间：
2011-05-27
影响因子：
6.3
作者：
Daley, Monica A.;Biewener, Andrew A.
通讯作者：
Biewener, Andrew A.
影响因子：
2.8
作者：
Daley, M. A.;Felix, G.;Biewener, A. A.
通讯作者：
Biewener, A. A.