Weights and variability of components of the human vertebral column

Abstract

Abstract Principal vertebral segments and individual vertebrae of 83 Asian skeletons were weighed and the data treated statistically. Average weight in grams per unit vertebra in the cervical segment was 6.3, in the thoracic, 8.7, in the lumbar, 17.9 and in the sacrum, 10.6. Mean weights of segments of this series were the lightest of the populations compared except those of the American White and Japanese females. Individual vertebral weights increased in caudad sequence except that the first two cervical and first two thoracic were respectively heavier than the third cervical and third thoracic. Mean weights of the twelfth thoracic, fifth lumbar and the sacrum were approximate multiples of that of the seventh cervical. The third cervical was the lightest in the column. The cervical segment represented 15% of the weight of the entire column, the thoracic segment 36%, lumbar 31%, sacral 18% and coccygeal 0.4%. Relative weights of individual vertebrae corresponded closely with those of other populations compared. Coefficients of variation ranged from 16% in the cervical segment, 19% in the thoracic, 17% in the lumbar, 18% in the sacral to 48% in the coccygeal. Variation was least in the second cervical and greatest in the third thoracic vertebra.