Scaling of form and function in the xenarthran femur: a 100-fold increase in body mass is mitigated by repositioning of the third trochanter
Scaling of form and function in the xenarthran femur: a 100-fold increase in body mass is mitigated by repositioning of the third trochanter
复制标题
xenarthran 股骨的形式和功能缩放：通过第三转子的重新定位减轻了体重 100 倍的增加
DOI：
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
P. O’Higgins
中科院分区：
文献类型：
--
作者：
N. Milne;P. O’Higgins
动物如何科普体型的增长是生物学中的一个关键问题。在这里，我们考虑xenarthrans的缩放，特别是股骨的形式和功能如何变化，以适应3公斤的犰狳和它的巨大的相对300公斤雕齿兽之间的大小范围。已经注意到，这些动物之间的股骨形态不同，这表明这反映了雕齿兽对尺寸增加的新适应。我们测试这一想法，通过应用冠状面的力量，这些动物的股骨模型的有限元分析，模拟在后肢的立场相，其中股骨受到弯曲，由于纵向压缩以及外展载荷的大转子。我们使用这些模型来检查的假设，附着在第三转子（T3）的肌肉可以减少这种弯曲的负载股骨和T3的力量是更有效地减少弯曲的雕齿，其中T3位于膝盖的水平。该分析使用传统的有限元方法来产生应变图，并检查股骨上200个点的应变。这些点在加载前后的坐标也被用来进行几何形态测量（GM）分析的总变形的模型在不同的加载方案。结果表明，纵向压缩和外展肌负荷增加了冠状面的弯曲，而施加到T3的负荷减少了弯曲。在雕齿模型中，T3载荷更有效，并且可以更容易地补偿由于纵向载荷和外展肌载荷引起的弯曲。这项研究也证明了有用的GM方法在解释有限元分析的结果。
How animals cope with increases in body size is a key issue in biology. Here, we consider scaling of xenarthrans, particularly how femoral form and function varies to accommodate the size range between the 3 kg armadillo and its giant relative the 300 kg glyptodont. It has already been noted that femoral morphology differs between these animals and suggested that this reflects a novel adaptation to size increase in glyptodont. We test this idea by applying a finite element analysis of coronal plane forces to femoral models of these animals, simulating the stance phase in the hind limb; where the femur is subject to bending owing to longitudinal compressive as well as abduction loads on the greater trochanter. We use these models to examine the hypothesis that muscles attaching on the third trochanter (T3) can reduce this bending in the loaded femur and that the T3 forces are more effective at reducing bending in glyptodont where the T3 is situated at the level of the knee. The analysis uses traditional finite element methods to produce strain maps and examine strains at 200 points on the femur. The coordinates of these points before and after loading are also used to carry out geometric morphometric (GM) analyses of the gross deformation of the model in different loading scenarios. The results show that longitudinal compressive and abductor muscle loading increases bending in the coronal plane, and that loads applied to the T3 reduce that bending. In the glyptodont model, the T3 loads are more effective and can more readily compensate for the bending owing to longitudinal and abductor loads. This study also demonstrates the usefulness of GM methods in interpreting the results of finite element analyses.
影响因子：
56.9
作者：
BIEWENER, AA
通讯作者：
BIEWENER, AA