Point of view

摘要

Several major structural, mechanical, and biological differences exist between the spines of humans and sheep that may prevent extrapolating these results to humans. Among these are differences in spinal geometry and anatomy1'2 and potential differences in mechanical loading between bipeds and quadrupeds. In addition, the authors loaded sheep lumbar specimens exclusively during flexion and compression, but ignored the roles of other loading conditions in contributing to herniation. Other modes of loading, or a combination of different loads applied simultaneously, may play significant roles in causing lumbar disc herniation.