Most low back pain results from mechanical disorders of the spine, which are commonly related to overuse.  Mechanical disorders of the spine are caused by localized problems involving the bones, joints, ligaments, muscles, tendons, or nerves of the back.  Causes for mechanical back pain include injury, deformity, degenerative disc disease, herniated disc, muscular sprain/strain, muscle spasm, and poor posture.  It is estimated that up to 85-90% of back pain is mechanical in origin.  The other 10-15% of cases are secondary to other underlying medical or organic causes.  Systemic illness and organ disease can refer or contribute to back pain.  It may present in a manner very similar to mechanical back pain.  Mechanical back pain is generally associated with reproducible characteristics during movement or in certain positions.  During the course of an evaluation the attending spine specialists is usually able to bring on or magnify the back pain with various tests or certain postures.   

The specific cause of mechanical back pain is also influenced by certain positions of the spine.  For example, an individual with a disc herniation may feel more pain when they bend forward, whereas an individual with spinal arthritis is more likely to experience increased low back when leaning back while sitting or standing, a position which places more stress on the spinal (facet) joints. Most medical disorders, which cause neck or back pain do not follow such a specific pattern.  They may not get better or worse with activity, rest, or in certain positions. Most mechanical back pain heals or improves over time.  A small percentage of individuals with mechanical back pain will require surgical intervention.  It is possible for mechanical and medical back pain to coexist.  If this is suspected, the individual should undergo a broader range of diagnostic procedures to help determine the cause of the pain and the most appropriate treatment.