In case of general thinning of intervertebral substance unequally divided between different sections of the spine the record will show that almost every vertebra is listed either S or I, and if a system of underscoring is used that these two directions are frequently indicated as most noticeable. A study of the spine will make clear the fact that if the cartilage between any two Dorsal vertebrae be thinned in front the bodies of the vertebrae will be closer together and the spinous processes more widely separated; the spinous process of the upper vertebra will be crowded against the one superior to it and that of the lower against the one inferior to it. These spinous processes are said to be _approximated_. The correction of S or I subluxations, then, depends upon correction of disturbed nutritive processes. Lateral Displacements According to the usage of earlier writers on subluxations this term (lateral displacement) included rotation of the vertebra as well as those changes in position in which the whole or nearly all of the vertebra deviates sidewise from its normal position. Since the introduction of the term “rotation” into the description of subluxations, the meaning of the term “lateral displacement” is much more restricted. It refers now to a condition which probably occurs in the strictest sense only in the Cervical region, most frequently with the first and second Cervical, the two being subluxated together. We have already stated that the most important fact to be determined regarding the Atlas is its lateral displacement, since this produces the greatest impingement of nerves. Lateral displacement of any other Cervical can best be judged by examination of the transverse processes, since by palpation of the spinous process alone it is quite impossible to distinguish between lateral and rotary subluxation. In the Dorsal and Lumbar regions the R or L used to describe the position of the spinous process most often indicates rotation of the vertebra. While it is perfectly proper thus to describe the subluxation on a record, in the determining of the form of adjustment to be used the position of the _whole_ vertebra must be considered. Anterior Subluxations Forward displacements may occur anywhere in the spine. In the case of the first Cervical they are usually, though not always, forward displacements of only one side--rotation--though the whole Atlas may be anterior if the Axis has moved with it or is tipped so that the spinous process is much superior. This is rare. Any Cervical may be anterior; usually a series are anterior (if any) amounting to an increase in the Cervical curve--a lordosis. This condition may be corrected by transverse adjustments given from the front and side.