EMG ACTIVATION PATTERNS DURING FORCE PRODUCTION IN PRECISION GRIP .2. MUSCULAR SYNERGIES IN THE SPATIAL AND TEMPORAL DOMAIN
EMG ACTIVATION PATTERNS DURING FORCE PRODUCTION IN PRECISION GRIP .2. MUSCULAR SYNERGIES IN THE SPATIAL AND TEMPORAL DOMAIN
复制标题
DOI：
10.1007/bf00241970
复制
发表时间：
1995-02-01
影响因子：
2
通讯作者：
HEPPREYMOND, MC
中科院分区：
文献类型：
--
作者：
MAIER, MA;HEPPREYMOND, MC
肌电图（EMG）活动进行了分析的协同模式的发生在稳定保持期间的力量在精确的抓地力。为了建立在振幅（空间）域中的肌肉协同作用的存在下，对同时活跃的肌肉的EMG激活水平线性相关。计算EMG活动的交叉相关性，以量化时空域中的肌肉协同作用（同步）。肌肉对被定义为协同耦合或同步激活时的相关性（幅度域）或互相关（时域）是显着的三个稳态力水平的至少两个。在振幅域中的肌肉协同作用被发现在三分之一的213肌肉对测试，分布在47的82个测试肌肉组合。共激活是主要的协同模式，而权衡包括不超过23%的协同作用。互相关峰值大小在自相关大小的5%和39%之间变化，延迟在+/-8 ms的范围内，基部宽度在12和20 ms之间。在测试的213个肌肉对中的四分之一和82个肌肉组合中的35个中发现了同步，即，频率低于EMG活动水平的协变。然而，个体间的患病率是较高的同步比在振幅域的协同作用，因为，对于协同肌肉组合，几乎两倍的肌肉对被发现同步比耦合在振幅域。在这两个领域的协同作用独立地发生在一些对和同时在其他情况下，并观察肌肉之间移动拇指，食指，或两个手指。由同一周围神经分支支配的肌肉对的同步性（46%）比由不同神经支配的肌肉对的同步性（18%）更常见。幅度域中的协同作用以相似的比例分布在内在的，外在的，以及这两种类型的肌肉的组合，而同步主要发生在对内在肌肉。当任务重复与略低的目标力，有较少的协同作用在振幅域（在52的213对，分布在35的82肌肉组合）和它们的分布发生变化，表明一个灵活的，力依赖性机制。总之，在空间域中，没有严格一致的个体间协同模式可以建立。
Electromyographic (EMG) activity was analyzed for the occurrence of synergistic patterns during the steady hold periods of force in the precision grip. To establish the presence of muscle synergies in the amplitude (spatial) domain, the EMG activation levels of pairs of simultaneously active muscles were linearly correlated. Cross-correlations of EMG activity were computed to quantify muscle synergies in the spatiotemporal domain (synchronization). A muscle pair was defined to be synergistically coupled or synchronously activated when the correlation (amplitude domain) or cross-correlation (time domain) was significant for at least two of the three steady state force levels. Muscle synergies in the amplitude domain were found in one-third of the 213 muscle pairs tested, distributed among 47 of the 82 tested muscle combinations. Coactivation was the predominant synergistic pattern, whereas trade-off comprised not more than 23% of the synergies. Cross-correlation peak size varied between 5 and 39% of the autocorrelation size, with delays in the range of +/-8 ms and base width between 12 and 20 ms. Synchronization was found in one-fourth of the 213 muscle pairs tested and among 35 of the 82 muscle combinations, i.e., less frequently than covariation of EMG activity levels. However, the interindividual prevalence was higher for synchronization than for synergies in the amplitude domain, since, for the synergistic muscle combinations, almost twice as many muscle pairs were found to be synchronized than coupled in the amplitude domain. Synergies in the two domains occurred independently in some pairs and concurrently in other cases, and were observed between muscles moving the thumb, the index finger, or both digits. Synchronization was more frequent in pairs of muscles supplied by branches of the same peripheral nerve (46%) than in those innervated by different nerves (18%). Synergies in the amplitude domain were distributed in similar proportions across intrinsic, extrinsic, and combinations of both types of muscles, whereas synchronization mainly occurred in pairs of intrinsic muscles. When the task was repeated with slightly lower target forces, there were fewer synergies in the amplitude domain (in 52 of the 213 pairs, distributed among 35 of 82 muscle combinations) and their distribution changed, indicating a flexible, force-dependent mechanism. In conclusion, no strictly coherent interindividual pattern of synergies in the spatial domain could be established.