Common muscle synergies for control of center of mass and force in nonstepping and stepping postural behaviors
Common muscle synergies for control of center of mass and force in nonstepping and stepping postural behaviors
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DOI：
10.1152/jn.00549.2010
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发表时间：
2011-08-01
影响因子：
2.5
通讯作者：
Ting, Lena H.
中科院分区：
文献类型：
--
作者：
Chvatal, Stacie A.;Torres-Oviedo, Gelsy;Ting, Lena H.
Chvatal SA，Torres-Oviedo G，Safavynia SA，Ting LH.在不迈步和迈步姿势行为中控制重心和力的常见肌肉协同作用。J Neurophysiol 106：999-1015，2011.首次发表于2011年6月8日; doi：10.1152/jn.00549.2010.-我们研究了肌肉活动，地面反作用力，和质心（CoM）加速度在两个不同的姿势行为站立平衡控制在人类，以确定是否共同的神经机制在不同的姿势任务。我们比较了nonstepping响应，支持的基础是固定的和平衡恢复返回CoM回到其初始位置，与步进响应，支持的基础是扩大和平衡恢复推CoM远离初始位置。在相同方向的扰动下，这两种姿势行为导致不同的肌肉活动和地面反作用力。我们假设，一个共同的池肌肉协同作用产生一致的任务水平的生物力学功能是用来产生不同的姿势行为。提出了两组在12个水平面方向上的支撑表面平移，首先引起步进响应，然后引起非步进响应。测量了16块站立腿下背部和腿部肌肉的肌电图。最初（类似于100毫秒的潜伏期），肌电图，CoM加速度，和力量是相似的nonstepping和步进响应，但这些分歧在以后的时间段（类似于200毫秒），当步进发生。我们使用非负矩阵分解和功能性肌肉协同作用来确定肌肉协同作用，该肌肉协同作用量化了肌肉协同作用募集水平和生物力学输出之间的相关性。功能性肌肉协同作用，产生的力量，以恢复在nonstepping响应的CoM的位置也被用来取代在步进响应的CoM。这些结果表明，肌肉协同作用代表共同的神经机制CoM运动控制在不同的动态条件下：步进和nonstepping姿势反应。
Chvatal SA, Torres-Oviedo G, Safavynia SA, Ting LH. Common muscle synergies for control of center of mass and force in nonstepping and stepping postural behaviors. J Neurophysiol 106: 999-1015, 2011. First published June 8, 2011; doi:10.1152/jn.00549.2010.-We investigated muscle activity, ground reaction forces, and center of mass (CoM) acceleration in two different postural behaviors for standing balance control in humans to determine whether common neural mechanisms are used in different postural tasks. We compared nonstepping responses, where the base of support is stationary and balance is recovered by returning CoM back to its initial position, with stepping responses, where the base of support is enlarged and balance is recovered by pushing the CoM away from the initial position. In response to perturbations of the same direction, these two postural behaviors resulted in different muscle activity and ground reaction forces. We hypothesized that a common pool of muscle synergies producing consistent task-level biomechanical functions is used to generate different postural behaviors. Two sets of support-surface translations in 12 horizontal-plane directions were presented, first to evoke stepping responses and then to evoke nonstepping responses. Electromyographs in 16 lower back and leg muscles of the stance leg were measured. Initially (similar to 100-ms latency), electromyographs, CoM acceleration, and forces were similar in nonstepping and stepping responses, but these diverged in later time periods (similar to 200 ms), when stepping occurred. We identified muscle synergies using non-negative matrix factorization and functional muscle synergies that quantified correlations between muscle synergy recruitment levels and biomechanical outputs. Functional muscle synergies that produce forces to restore CoM position in nonstepping responses were also used to displace the CoM during stepping responses. These results suggest that muscle synergies represent common neural mechanisms for CoM movement control under different dynamic conditions: stepping and nonstepping postural responses.