Pectoral girdle and forelimb musculoskeletal function in the echidna ( Tachyglossus aculeatus ): insights into mammalian locomotor evolution
Pectoral girdle and forelimb musculoskeletal function in the echidna ( Tachyglossus aculeatus ): insights into mammalian locomotor evolution
复制标题
针鼹（Tachyglossus aculeatus）的胸带和前肢肌肉骨骼功能：对哺乳动物运动进化的见解
DOI：
10.1098/rsos.181400
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发表时间：
2018
影响因子：
3.5
通讯作者：
Pierce, Stephanie E.
中科院分区：
文献类型：
--
作者：
Regnault, Sophie;Pierce, Stephanie E.
虽然进化转型的肩带和前肢似乎有深远的影响，哺乳动物的运动和生态多样性，无论是解剖学变化的顺序和功能的影响仍然不清楚。单孔目动物可以提供深入了解这一进化转型的一个重要阶段，由于他们的系统发育地位的姐妹群兽亚目哺乳动物和他们的马赛克的近形和衍生功能。在这里，我们建立了一个肌肉骨骼计算机模型的针鼹鼠肩带和前肢估计关节的运动范围（ROM）和肌肉力矩臂（MMA）-两个基本的描述符的生物力学功能。我们发现针鼹鼠的骨骼形态限制肩胛喙突的流动性和盂肱关节的屈伸与兽相比。估计肩部ROM和跨肩肌肉的MMA表明，针鼹肩带和前肢的形态优化肱骨内收和内旋，符合limitedin vivodata。此外，更多的肌肉行动，以产生肱骨长轴旋转针鼹相比，兽，作为肌肉几何形状的差异的结果。我们的肌肉骨骼模型允许解剖和功能的相关性，并可以指导假设功能的灭绝类群和形态和运动的转变，导致兽目哺乳动物。
Although evolutionary transformation of the pectoral girdle and forelimb appears to have had a profound impact on mammalian locomotor and ecological diversity, both the sequence of anatomical changes and the functional implications remain unclear. Monotremes can provide insight into an important stage of this evolutionary transformation, due to their phylogenetic position as the sister-group to therian mammals and their mosaic of plesiomorphic and derived features. Here we build a musculoskeletal computer model of the echidna pectoral girdle and forelimb to estimate joint ranges of motion (ROM) and muscle moment arms (MMA)—two fundamental descriptors of biomechanical function. We find that the echidna's skeletal morphology restricts scapulocoracoid mobility and glenohumeral flexion–extension compared with therians. Estimated shoulder ROMs and MMAs for muscles crossing the shoulder indicate that morphology of the echidna pectoral girdle and forelimb is optimized for humeral adduction and internal rotation, consistent with limitedin vivodata. Further, more muscles act to produce humeral long-axis rotation in the echidna compared to therians, as a consequence of differences in muscle geometry. Our musculoskeletal model allows correlation of anatomy and function, and can guide hypotheses regarding function in extinct taxa and the morphological and locomotor transformation leading to therian mammals.