Biomechanics and biochemistry of the intervertebral disks: the need for correlation studies. 
The literature on the biomechanics of the intervertebral disk is reviewed with emphasis on biomechanical--biochemical--morphological correlative studies.  The deficiency of definitive correlative studies is apparent and an appeal is made to interested investigators to fill in the voids in this extremely important area of study.  A comprehensive theory of intervertebral disk failure awaits application of existing biomechanical, biochemical and morphological techniques in a detailed and methodical manner to the normal and early degenerative human intervertebral disks.