Causes of Back Pain

by | Jul 12, 2011

In order to discuss what treatments are performed, you need to understand some of the basic anatomy of the spine.  This article will concentrate on the lumbar spine.  The spine is covered and supported by many ligaments and muscle groups.  Beneath these muscles are the bones that form the spinal column.  The lumbar spine is made of 5 vertebral bones or vertebrae.  On this picture, labeled “T12” is the last thoracic vertebral body, and “L5” is the last lumbar vertebral body.  The spine sits upon the sacrum, labeled “7”.  Labeled number “5” is the iliac crest.  So between “5 and 7” is the Sacroiliac joint, which is the lowest major joint of the spine.  On this picture you also see the nerves labeled “11” which innervate the groin and thigh, and nerves labeled “12 and 13’ which form the Sciatic nerve, innervating the leg.

The next picture depicts one vertebral body on top of another.  In the front (left side) you see the intervertebral disk between the two bones.  The disk is made up of the Nucleus Pulposus surrounded by the Annulus Fibrosus.  This acts as a cushion between the vertebral bodies.  Just to the right of the disk is the neuroforamen.  This is the hole that the nerves exit to travel to the lower extremity.  Anything that puts pressure on the nerve (here labeled the Dorsal Root Ganglion) will produce pain down the leg.  This can involve the disk pressing on the nerve, the ligamentum flavum (which are ligaments behind the nerve) or the facet joint (labeled Articular capsule).

These diagrams again show how the disk in the front, the spinal cord and nerves just behind it, and the ligaments and bones in the back.  You see how the nerves exit the bones, and how any surrounding structures could pinch the nerves, causing pain.

This picture shows how disks are tested to determine if they are causing the pain.  This is called a diagnostic lumbar discography.

All of the various structures of the spine can be tested to determine if they are causing the pain.  These tests are much better and more sensitive than MRIs because they are dynamic (the patient reports a response) as opposed to an MRI which is just a static picture.  It is this which gives pain physicians a powerful tool to diagnose and treat patients who are suffering from neck or back pain, as well as other ailments.