The Effect of the Achilles Tendon on Trabecular Structure in the Primate Calcaneus
Article first published online: 3 JUL 2013
Copyright © 2013 Wiley Periodicals, Inc.
The Anatomical Record
Volume 296, Issue 10, pages 1509–1517, October 2013
How to Cite
Kuo, S., Desilva, J. M., Devlin, M. J., Mcdonald, G. and Morgan, E. F. (2013), The Effect of the Achilles Tendon on Trabecular Structure in the Primate Calcaneus. Anat Rec, 296: 1509–1517. doi: 10.1002/ar.22739
- Issue published online: 13 SEP 2013
- Article first published online: 3 JUL 2013
- Manuscript Accepted: 18 MAY 2013
- Manuscript Revised: 13 MAR 2013
- Manuscript Received: 28 JUL 2012
- Boston University Undergraduate Research Opportunities Program
- trabecular bone;
- Achilles tendon;
Humans possess the longest Achilles tendon relative to total muscle length of any primate, an anatomy that is beneficial for bipedal locomotion. Reconstructing the evolutionary history of the Achilles tendon has been challenging, in part because soft tissue does not fossilize. The only skeletal evidence for Achilles tendon anatomy in extinct taxa is the insertion site on the calcaneal tuber, which is rarely preserved in the fossil record and, when present, is equivocal for reconstructing tendon morphology. In this study, we used high-resolution three-dimensional microcomputed tomography (micro-CT) to quantify the microstructure of the trabecular bone underlying the Achilles tendon insertion site in baboons, gibbons, chimpanzees, and humans to test the hypothesis that trabecular orientation differs among primates with different tendon morphologies. Surprisingly, despite their very different Achilles tendon lengths, we were unable to find differences between the trabecular properties of chimpanzee and human calcanei in this specific region. There were regional differences within the calcaneus in the degree of anisotropy (DA) in both chimpanzees and humans, though the patterns were similar between the two species (higher DA inferiorly in the calcaneal tuber). Our results suggest that while trabecular bone within the calcaneus varies, it does not respond to the variation of Achilles tendon morphology across taxa in the way we hypothesized. These results imply that internal bone architecture may not be informative for reconstructing Achilles tendon anatomy in early hominins. Anat Rec, 296:1509–1517, 2013. © 2013 Wiley Periodicals, Inc.