Exploring the high-dimensional structure of muscle redundancy via subject-specific and generic musculoskeletal models.
Exploring the high-dimensional structure of muscle redundancy via subject-specific and generic musculoskeletal models.
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DOI：
10.1016/j.jbiomech.2015.04.026
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发表时间：
2015-08-20
影响因子：
2.4
通讯作者：
Lawrence EL
中科院分区：
文献类型：
--
作者：
Valero-Cuevas FJ;Cohn BA;Yngvason HF;Lawrence EL
特定主题和通用肌肉骨骼模型是假设的计算实例化，随机技术有助于探索其有效性。我们提出两个这样的例子来探讨肌肉冗余的假设。第一项研究解决了解剖变异对三个独立猫后肢静力能力的影响，每个后肢有7个运动自由度（dfs）和31块肌肉。我们提出了新的方法来表征31维可行的肌肉激活集的结构，以在每个三维方向上产生静力。我们发现，任务要求强烈地定义了可行的肌肉激活和肢体力的集合，在个体和物种的平均结果之间几乎没有差异。此外，肌肉活动在三维方向上并不均匀分布。第二个例子探讨了飞碟投掷运动中的参数不确定性，通过使用具有五个自由度和17块肌肉的一般人类手臂来预测肌纤维速度。我们表明，测量关节运动学完全约束所有肌肉的偏心和同心纤维速度通过他们的力臂。因此，肢体运动的肌肉激活可能不是多余的：如果有的话，在同步α - γ运动神经元的兴奋-抑制方面，肌肉几乎没有余地，以坚持由关节运动学决定的时间临界纤维速度。重要的是，一些肌肉不可避免地表现出比想象中高的纤维速度，即使是保守的投掷速度。这些技术和结果，分别使我们能够和迫使我们继续修改肌肉冗余的经典概念，以适应越来越现实的模型和任务。
Subject-specific and generic musculoskeletal models are the computational instantiation of hypotheses, and stochastic techniques help explore their validity. We present two such examples to explore the hypothesis of muscle redundancy. The first addresses the effect of anatomical variability on static force capabilities for three individual cat hindlimbs, each with seven kinematic degrees of freedom (DoFs) and 31 muscles. We present novel methods to characterize the structure of the 31-dimensional set of feasible muscle activations for static force production in every 3-D direction. We find that task requirements strongly define the set of feasible muscle activations and limb forces, with few differences comparing individual vs. species-average results. Moreover, muscle activity is not smoothly distributed across 3-D directions. The second example explores parameter uncertainty during a flying disc throwing motion, by using a generic human arm with five DoFs and 17 muscles to predict muscle fiber velocities. We show that the measured joint kinematics fully constrain the eccentric and concentric fiber velocities of all muscles via their moment arms. Thus muscle activation for limb movements is likely not redundant: there is little, if any, latitude in synchronizing alpha-gamma motoneuron excitation-inhibition for muscles to adhere to the time-critical fiber velocities dictated by joint kinematics. Importantly, several muscles inevitably exhibit fiber velocities higher than thought tenable, even for conservative throwing speeds. These techniques and results, respectively, enable and compel us to continue to revise the classical notion of muscle redundancy for increasingly more realistic models and tasks.
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影响因子：
3.8
作者：
Holzbaur, KRS;Murray, WM;Delp, SL
通讯作者：
Delp, SL
DOI：
10.1098/rspb.1938.0050
发表时间：
1938-10-01
期刊：
PROCEEDINGS OF THE ROYAL SOCIETY SERIES B-BIOLOGICAL SCIENCES
影响因子：
--
作者：
Hill, AV
通讯作者：
Hill, AV
影响因子：
29.3
作者：
ARBIB, MA
通讯作者：
ARBIB, MA
DOI：
10.1523/jneurosci.0853-09.2009
发表时间：
2009-07-08
期刊：
The Journal of neuroscience : the official journal of the Society for Neuroscience
影响因子：
--
作者：
Keenan KG;Santos VJ;Venkadesan M;Valero-Cuevas FJ
通讯作者：
Valero-Cuevas FJ
影响因子：
2.4
作者：
KUO, AD;ZAJAC, FE
通讯作者：
ZAJAC, FE