An initial evaluation of the relationship between human pelvic size and shape and the distribution, type and severity of vertebral degenerative disease in archaeological material.

Abstract

Keyývords bipedal adaptation;pelvic shape; pelvic dimensions;vertebral degenerative disease. In order to adopt an efficient bipedal postureand method of locomotion, tile human skeleton has evolved a curved vertebral column and a stable, compact male pelvic girdle. Adaptive vertebral curves and the force of gravity render it susceptible to injury and degenerative change. This study examines if there is any association between pelvic size and shape and the distribution, type and severity of vertebral degenerative disease. Four documented North- west European, middle-class skeletal samples from the eighteenth and nineteenth century were examined. Pelvic shape and size were recorded, the latter of which necessitated the measurementof 93 dimensions. The severity and distribution of osteophytes, porosity and eburnation in the vertebral column were recorded. Statistical analysis was undertaken of relationships between pelvic measurements and tile sex and age at death of individuals as well as correlations between the measurements themselves. The relationship between pelvic shape and degenerative disease was also investigated. The correlation between measurements in the pelvis and disease were examined and a mechanism was created to display this relationship. Results demonstrated that this sample exhibited significant din-iorphic differcrices in pelvic measurements and pelvic shape between the sexes. Significant correlations were found between age and pelvic dirriensions in five (331/o)sacral, 29 (94%) innominate and four (25%) reconstructed pelvis measurements. Correlations were small but positive for both sexes in the sacrum and innorninate. In the reconstructed pelvis, significant correlations were again small, but Positive in females and negative in males, suggesting that although a larger pelvis may be selected for in older females, the opposite is occurring with males. This supports the theory of an evolutionary effect selecting for females with larger pelves and males with more compact pelves. Statistical analyses of tile relationship between pelvic shape and the severity or presence/absence of degenerative disease were limited and not deemed to have any statistical ment. A 'signpost' configuration was created to graphically display results of correlations between individual measurements and disease. Results suggest that osteophytosis was the most common type of disease encountered and the superior and inferior body surfaces were the main areas affected, particularly in the lower half of the thoracic and lumbar regions. All, correlations, except one, were positive, implying a positive association between those measurements and the degree of degenerative change. Patterning of the correlations was identified and discussed and statistical differences between correlations at levels of maximum and minimum curvature were examined. Results suggest that particular pelvimetry plays a significant role in this at levels of maximum and minimuni curvature. Discriminant function analysis was employed to explore the predictive ability of combinations of measurements to predispose to the development and severity of osteophytosis on the superior vertebral body surface. Contrived data was then used to test this model and was successful in predicting an expected level of expression of pathological change.