STRUCTURAL CHANGES IN THE LOWER LIMB BONES WITH AGING AT PECOS PUEBLO.

Format:

Book

Thesis/Dissertation

Author/Creator:

RUFF, CHRISTOPHER BRITTON.

Contributor:

University of Pennsylvania.

Subjects (All):

Physical anthropology.

0327.

Local Subjects:

0327.

Physical Description:

505 pages

Contained In:

Dissertation Abstracts International 42-06A.

System Details:

Mode of access: World Wide Web.

text file

Summary:

To interpret structural variation in the skeleton in biomechanical terms, accurate measurements of important structural characteristics, including cross-sectional geometry, must be available. In addition, because of normal inter-individual variation in these properties, large numbers of individuals are necessary if clear sex and age differences are to be determined. In the present study, structural data, including cross-sectional geometric properties and bone mineral content, were gathered for a large sample of femora and tibiae from the Pecos Pueblo, New Mexico archaeological site.

120 skeletons, equally divided between males and females and six adult age groups, were obtained from the Pecos collection (Harvard Peabody Museum). Femora and tibiae were sectioned at five diaphyseal sites and one site through the femoral neck. Using interactive computer software (SLICE) and an electronic digitizer, cross section photographic slides were manually traced and used to determine all important section properties--bone areas, principal moments and their orientations, polar moment, section modulus. Bone mineral content (BMC) was determined using ('125)I photon absorptiometry. In addition, directly measured bone density was derived from femoral midshaft cores for a subset of the sample.

Major results of the study may be summarized as follows: (1) As in modern populations, with aging endosteal resorption and cortical thinning occur, more so in females. However, subperiosteal expansion with aging limits age-related losses in cortical area, and produces age-related increases in second moments of area, averaging 10% in males and 7% in females. (2) Cross-sectional geometric characteristics indicate that males in the sample are adapted for relatively higher A-P bending loads in the lower limb, females for M-L bending loads. This could be related to both sexual dimorphism in the pelvis and different sex-related activity patterns at Pecos. (3) Age changes in BMC closely parallel those in cortical area, and directly measured bone densities show little age reduction. Thus, age changes in compact bone are mainly volumetric, with no large changes in tissue density.

The results illustrate the fruitfulness of a combined biomechanical-demographic approach to these issues. Using these methods, structural differences in the skeleton are used to investigate in vivo mechanical stresses and their relationship to bone remodeling.

Notes:

Source: Dissertation Abstracts International, Volume: 42-06, Section: A, page: 2751.

Thesis (Ph.D.)--University of Pennsylvania, 1981.

Local Notes:

School code: 0175.

Access Restriction:

Restricted for use by site license.