Larson S G, Stern J T
Department of Anatomical Sciences, State University of New York at Stony Brook, New York, USA.
J Mot Behav. 1989 Dec;21(4):457-72. doi: 10.1080/00222895.1989.10735494.
In comparative anatomical studies of the shoulder, the humeral retractors are often grouped together as propulsive muscles, which are important in the propulsive stroke of the forelimb during quadrupedal locomotion. Electromyographic (EMG) analyses of these muscles in opossums, cats, and dogs in general have confirmed such conclusions. An EMG study of chimpanzee shoulder muscles during knuckle-walking found, however, that the humeral retractors are either inactive or perform a function unrelated to propulsion (Larson & Stern, 1987). This contrast in muscle recruitment patterns between chimpanzees and more "typical" mammalian quadrupeds was attributed to the derived morphology of the chimpanzee shoulder. The present study examines the activity patterns of the humeral retractors in the vervet monkey, a primate more closely resembling nonprimate mammals in its shoulder morphology. The results of this EMG analysis show that despite the significant differences in anatomy between chimpanzees and vervets, the two species display very similar muscle recruitment patterns during quadrupedalism, and there is evidence for this same pattern in other species of primates. These differences in muscle activity patterns between primates and nonprimate mammals may be related to changes in the neurological control of locomotion in primates due to the evolutionary development of manipulative abilities in the primate forelimb.
在肩部的比较解剖学研究中，肱骨后缩肌通常被归为推进肌，在四足动物运动过程中，这些肌肉在前肢的推进冲程中起着重要作用。一般对负鼠、猫和狗的这些肌肉进行的肌电图（EMG）分析证实了这些结论。然而，一项对黑猩猩在指关节行走时肩部肌肉的肌电图研究发现，肱骨后缩肌要么不活跃，要么执行与推进无关的功能（拉森和斯特恩，1987年）。黑猩猩与更“典型”的哺乳动物四足动物在肌肉募集模式上的这种差异归因于黑猩猩肩部的衍生形态。本研究考察了绿猴肱骨后缩肌的活动模式，绿猴是一种在肩部形态上比非灵长类哺乳动物更接近灵长类的动物。这项肌电图分析的结果表明，尽管黑猩猩和绿猴在解剖结构上存在显著差异，但这两个物种在四足行走时表现出非常相似的肌肉募集模式，并且在其他灵长类物种中也有这种模式的证据。灵长类和非灵长类哺乳动物在肌肉活动模式上的这些差异可能与灵长类动物由于前肢操作能力的进化发展而导致的运动神经控制变化有关。
