Structural adaptations of the femur and humerus to arboreal and terrestrial environments in three species of macaque

Abstract

One reason to measure cross-sectional structural properties of primate long bones is to define mechanically relevant complexes of traits that describe the adaptation of bone to different biomechanical environments. This can be effectively accomplished when congeneric species having different postural and locomotor behaviors are compared. This paper compares the cross-sectional geometry of the femur and humerus in three behaviorally different macaque species as a basis for defining such patterns. Cross-sectional moments of inertia in the standard anatomical planes were calculated at five locations along the diaphyses of the femur and humerus in Macaca fascicularis, M. nemestrina, and M. mulatta. The data suggest that the "barrel-shaped" femur is associated with behaviors for which long limbs and small body size are an asset. This may be associated with, but is not restricted to, leaping behaviors. The data also suggest that structural rigidity of the femur and humerus is greater per unit body weight in primates that spend significant amounts of time in terrestrial environments than in those that are more restricted to climbing in arboreal environments.

Cutting corners: the dynamics of turning behaviors in two primate species

“…The locomotor repertoire of the ring-tailed lemur is highly versatile, whereas that of the patas monkey is considerably more restricted and arguably the most stereotypic among primate species. Versatile and particularly arboreal locomotion has been related to highly variable loading regimes of long bones, and ultimately to circular bone diaphyses, whereas stereotypic, and particularly terrestrial locomotion, has been related to more uniform loading regimes and uniplanar expansion of bone diaphyses (Lovejoy et al, 1976;Jungers and Minns, 1979;Schaffler et al, 1985;Burr et al, 1989;Carlson, 2005). Even though the variation in turning forces is greater in the versatile species, supporting these assumptions, it is worth noting that the limbs of the presumed stereotypic patas monkey are exposed to substrate forces with lateral as well as medial directions during turns.…”

Radiographic estimation of long bone cross‐sectional geometric properties

“…Since long and museum specimens may not be secbone diaphyses can be modelled as engineer-tioned, (2) CT may not be available and may ing beams (e.g., Huiskes, 1982), cross-sec-not produce sufficient resolution below a tional diaphyseal properties employed in certain size limit, 1 and (3) X-ray machines beam analyses-areas and second moments are readily available at many institutions, of area-can be used to draw inferences re-including museums. Measurements of bone garding the mechanical loadings of limbs (Burr et al, 1981(Burr et al, , 1982(Burr et al, , 1989Demes and Jungers, 1989;Lovejoy et al, 1976;Ruff, 1987;Ruff and Hayes, 1983a,b;Schaffler et Received D~««*" *• i»i; »«*#«! July ie.…”

Locomotor Differentiation and Different Skeletal Morphologies in Mangabeys (Lophocebus and Cercocebus)

“…The structural strength of the femur varies in response to the intensity of locomo tor stresses imposed on the bone (28]. Thus, the circumference of the femoral shaft is a measure with which to estimate the magnitude of the stresses to which the femur is exposed.…”