The latter condition is rare. In case of doubt count the next two spinous processes above or below the point in question, and compare the space they occupy with the space occupied by the lesion and the spinous process next above or below it. The comparison will at once aid in determining the point. Points of anatomical weakness are frequently found at the junction of the twelfth dorsal with the first lumbar vertebra, also at the junction of the fifth lumbar with the sacrum. Separations at this point are common.
Marked tenderness is usually present.
The examining fingers are pressed firmly into the spinal muscles and moved transversely to the course of their fibres for the purpose of detecting any abnormal hardening or contracturing of them. Contractures generally affect certain sets of fibres rather than the muscle as a whole. They may be situated in the superficial or in the deep muscles, and may be primary or secondary according as they are produced by direct or indirect lesion of the fibres. It must be borne in mind that bony lesions are not alone important. Ligamentous lesions are quite as much so, and though they are not so generally discernible as are the former, the student must not forget that following upon and consequent to bony lesion they may bring pressure upon important structures, may thus interfere with the functions of blood-vessels, nerves, etc., and become a fruitful source of ill.