Laboratory of Animal Anatomy, Federal University of Pampa (UNIPAMPA), Uruguaiana, RS, Brazil.
Laboratory of Wild Animals Teaching and Research (LAPAS), Federal University of Uberlândia (UFU), Uberlândia, MG, Brazil.
J Anat. 2018 Dec;233(6):783-806. doi: 10.1111/joa.12892. Epub 2018 Oct 14.
The characteristics of the muscles of the thoracic limb were evaluated in 22 specimens of Lycalopex gymnocercus. Descriptive and comparative analyses showed similarity with other canids in terms of topography and tendon insertions. Differences with the domestic dog were observed in the pectoralis profundus, triceps brachii and interflexorii muscles. Intraspecific variations were observed in the rhomboideus capitis, serratus ventralis cervicis, extensor carpi radialis, extensor digiti I and II, lumbricales, flexor digiti I brevis, abductor digiti I brevis, and flexor digiti V muscles. The analyses of muscle architecture carried out in nine specimens showed that there was no difference in muscle percentage mass in the thoracic limb of males and females, but a young specimen showed significant lower percentage mass. The triceps brachii caput longus muscle showed the greatest mass, the subscapularis muscle showed the greatest physiological cross-sectional area value, and the extrinsic muscles, in general, presented the longest fascicles and higher architectural indexes. Muscle architecture data were compatible with those of a thoracic limb adapted to fast cursorial locomotion that prioritizes movements in a sagittal plane instead of rotation or adduction/abduction. There was a high association between functional percentage mass of the muscles in the thoracic limb and phylogeny in the Carnivora order. It may be inferred that carnivoran muscle mass is largely determined by phylogeny.
对 22 只鬃狼 Lycalopex gymnocercus 的胸肢肌肉特征进行了评估。描述性和比较分析表明，其在肌肉的形态和肌腱附着方面与其他犬科动物具有相似性。与家犬相比，在胸深肌、肱三头肌和内收肌方面存在差异。头半棘肌、颈腹侧锯肌、桡侧腕伸肌、指深屈肌 I 和 II、蚓状肌、指浅屈肌 I、指浅屈肌 I 短肌和指浅屈肌 V 等肌肉存在种内变异。在 9 个标本中进行的肌肉结构分析表明，雄性和雌性胸肢的肌肉百分比质量没有差异，但年轻标本的百分比质量显著较低。肱三头肌长头肌肉的质量最大，肩胛下肌的生理横截面积值最大，而外在肌肉的肌束通常最长，建筑指数也较高。肌肉结构数据与适应快速奔跑运动的胸肢相适应，这种运动优先在矢状面进行，而不是旋转或内收/外展。胸肢肌肉的功能百分比质量与食肉目动物的系统发育之间存在高度关联。可以推断，食肉动物的肌肉质量在很大程度上取决于系统发育。
