Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2012 Oct;221(4):311-7.
doi: 10.1111/j.1469-7580.2012.01545.x. Epub 2012 Jul 16.

Muscle dimensions of the foot in the orangutan and the chimpanzee

Motoharu Oishi  1 , Naomichi Ogihara, Hideki Endo, Yumi Une, Nobutsune Ichihara, Masao Asari, Hajime Amasaki
Affiliations

Muscle dimensions of the foot in the orangutan and the chimpanzee

Motoharu Oishi et al. J Anat. 2012 Oct.

Abstract

The hindlimbs of two orangutans and four chimpanzees were dissected, and muscle parameters (mass, fascicle length, and physiological cross-sectional area: PCSA) were determined to explore possible interspecies variation in muscle dimensions. Muscle mass and PCSA were divided by the total mass and total PCSA of the entire foot muscles for normalization. The results indicate that the pedal interosseous and the intrinsic pedal digital extensor muscles in the orangutans probably have higher capacity for force production due to their relatively larger PCSAs than in chimpanzees. Moreover, the medial components of the intrinsic muscles exhibited relatively larger mass and PCSA ratios in orangutans. The mass and PCSA ratios of the hallucal muscles were larger in chimpanzees. These differences in foot muscle dimensions of the two species suggest that the orangutan is more specialized for hook-like digital gripping without involvement of the rudimentary hallux, while the chimpanzee is adapted to hallux-assisted power gripping in arboreal locomotion.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Mass ratios of foot muscle groups in orangutans and chimpanzees. Mass ratios of each muscle group of the foot were averaged for orangutans and chimpanzees. Error bars show mean ± SD. Muscle group abbreviations are as detailed in Table 4.
Fig. 2
Fig. 2
PCSA ratios of foot muscle groups in orangutans and chimpanzees. PCSA ratios of each muscle group of the foot were averaged for orangutans and chimpanzees. Error bars show mean ± SD. Muscle group abbreviations are as detailed in Table 4.
See this image and copyright information in PMC

References

    1. Aiello L, Dean C. An Introduction to Human Evolutionary Anatomy. San Diego: Academic Press; 1990.
    1. Anapol F, Barry K. Fiber architecture of the extensors of the hindlimb in semiterrestrial and arboreal guenons. Am J Phys Anthropol. 1996;99:429–447. - PubMed
    1. Boyer EL. The musculature of the inferior extremity of the orang-utan Simia satyrus. Am J Anat. 1935;56:193–256.
    1. Burkholder TJ, Fingado B, Baron S, Lieber RL. Relationship between muscle fiber types and sizes and muscle architectural properties in the mouse hindlimb. J Morphol. 1994;221:177–190. - PubMed
    1. Carlson KJ. Muscle dimension of the common chimpanzee (Pan troglodytes): perspectives for investigating chimpanzee behavior. Primates. 2006;47:218–229. - PubMed

Publication types

MeSH terms