The spinal column has four functions:

• To house and protect the spinal cord.
• To support the hips and shoulders.
• To serve as an attachment to the muscles.
• To support the head and ribs.

Your spine is made up of spinal bones, or vertebrae, each of which has a hole in its center. Each hole lines up to form a canal where the spinal cord is located and protected. Spinal nerves emerge from the cord, exit between the vertebrae through a hole formed on the side, and travel throughout your body providing essential communication between your brain and all of your body tissues (organs, muscles, bones).

The spine consists of 24 vertebrae plus the sacrum and the coccyx. The first of the seven cervical (neck) vertebrae (C-1), called the “atlas,” holds the skull, as the god Atlas held up the earth. The second vertebrae (C-2), the “axis,” permits head turning and tilting. Cervical vertebrae C-3 through C-7 continue through the neck. The 12 thoracic (mid-back) vertebrae (T-1 through T-12) all connect to the ribs in back, and all but two (T-11 and T-12, which “float”) join the sternum (or breastbone) in front. The five lumbar (lower back) vertebrae are the biggest, thickest, and most massive. They support the weight of the entire spine, and that’s one reason why so many spinal problems are in the lower back (lumbar) area.

The sacrum is a triangular-shaped bone made up of five fused vertebrae. The sacrum and the hips on either side make up the pelvis. Located where the sacrum and the hips join are the sacroiliac joints. These joints often are the source of lower back pain, leg pain or groin pain.

The coccyx, from the Greek kokkyx (cuckoo) so called because it resembles the beak of the cuckoo bird, comprises four fused vertebrae, and is what’s left of the human tailbone.

Spinal Curves

The cervical, thoracic, and lumbar curves give your spine strength, stability, and flexibility. The neck and lower back curves have a normal forward bend, and the mid-back curve has a normal backwards bend. In an unhealthy spine, the curves change: they can reduce, exaggerate, or even reverse causing increased wear and tear on your spine’s delicate parts! Over time you develop arthritic changes which are permanent and cannot be undone. These changes affect the way your spine functions and can create significant pain and gradually increasing disability. Viewed from the front or back, the spine appears to be more-or-less straight.