Back To Anatomy
Let’s examine the back. With feet as the foundation, the back constitutes the structural support for those with intact spinal integrity. The human spine, a marvelously intricate column of 33 bones (vertebrae) woven together with ligaments and muscles, gives strength yet flexibility to the body. By restricting motion to within definite bounds, the bones provide protection for the delicate spinal cord, the superhighway of nerves running down the center of the vertebrae.
The top seven bones of the spine work with the muscles of the neck to carry the head. These cervical vertebrae are the smallest and most flexible in the spinal column. Twelve thoracic vertebrae have ribs attached to them that gird the chest cavity and lend extra strength to the midback. Because the bottom two thoracic vertebrae are attached to ribs that float freely in front–the first 10 ribs attach to the sternum in front–the low thoracic spine provides a lot of rotational freedom.
But the lower back, with five lumbar vertebrae, has the largest components of the spine and bears the greatest load with the least flexibility and, consequently, gets the most votes as Area Most Likely to Hurt.
Below the lumbar spine, a lump of bones called the sacrum holds the pelvis in place. Finally, the functionless little coccyx reminds us, perhaps, that we once extended farther in that direction. The five fused bones of the sacrum the and four of the coccyx brings the total to 33.