McConathy D, Giddings C J, Gonyea W J
J Morphol. 1983 Mar;175(3):279-92. doi: 10.1002/jmor.1051750306.
Investigations of the structure and function of the flexor carpi radialis muscle (FCR) in the cat have led to the hypothesis that the compartmentalized (nonuniform) distribution of fiber types within the muscle relate to the complex motor skills of the cat. To test this hypothesis a study was undertaken to compare the FCR in four mammalian species of similar body size but with different forelimb motor tasks. The species chosen were: dog, opossum, armadillo, and cat. Comparisons were made among species with regard to general muscle morphology, fiber types and sizes, fiber proportions, and fiber distributions. The FCR of all species was morphologically similar and contained three muscle fiber types (SO, FOG, and FG). The mean area of muscle fibers was largest in opossum, while the FCR fibers of dogs were smallest. The percentage of SO fibers in the dog FCR was greater than in the other species studied. The opossum FCR also contained a high percentage of SO fibers. The armadillo FCR consisted of a high percentage of FG fibers. In the cat FCR the percentages of all three fiber types were similar. For each species, individual fiber proportions were in agreement with the results for fiber percentages. Compartmentalized distribution of fiber types existed in each species with the dog having the most compartmentalized fiber type distribution and the cat the least compartmentalized distribution. Therefore it seems that the compartmentalized organization of the FCR is not related to any specialized motor task, but may be a generalized pattern associated with motor patterns shared among all species studied.
对猫的桡侧腕屈肌（FCR）的结构和功能进行研究后，得出了这样一个假设：肌肉内纤维类型的分区（不均匀）分布与猫的复杂运动技能有关。为了验证这一假设，开展了一项研究，比较四种体型相似但前肢运动任务不同的哺乳动物的FCR。所选的物种为：狗、负鼠、犰狳和猫。对这些物种在一般肌肉形态、纤维类型和大小、纤维比例以及纤维分布方面进行了比较。所有物种的FCR在形态上相似，均包含三种肌肉纤维类型（慢氧化型，SO；快收缩抗疲劳型，FOG；快收缩型，FG）。负鼠的肌肉纤维平均面积最大，而狗的FCR纤维最小。狗的FCR中SO纤维的百分比高于其他所研究的物种。负鼠的FCR中也含有高比例的SO纤维。犰狳的FCR由高比例的FG纤维组成。在猫的FCR中，三种纤维类型的百分比相似。对于每个物种，个体纤维比例与纤维百分比的结果一致。每个物种都存在纤维类型的分区分布，其中狗的纤维类型分布分区最明显，而猫的分区分布最不明显。因此，似乎FCR的分区组织与任何特定的运动任务无关，而可能是一种与所有所研究物种共有的运动模式相关的普遍模式。
