Causes of Lower Back Pain

We all will experience lower back pain at one point or another in our lifetime. In some cases, it will last for a long enough period which will drive us to find out the true cause of the problem. The sooner we can learn about possible causes, the sooner we can often rid of our problem and prevent it from ever arising again!

Non-Spinal Causes of Lower Back Pain

Some of the body's areas from which back arises include:

- Kidney or Bladder Infection, Kidney Stone (associated fever, blood in the urine)

- Stomach/Duodenal Ulcer (associated heartburn, nausea, indigestion)

- Gynaecoloic Problems: endometriosis, ectopic pregnancy, fibroids, infection (associated irregular bleeding, pain with periods, vaginal discharge)

- Pancreatic Inflammation or Pancreatitis (associated history of bile stones, alchohol abuse, recent infection)

- Enlarged Abdominal Aorta (severe, unremitting, rapidly worsening lower back pain)

The 2 Most Common Spinal Causes of Lower Back Pain

1. Disc Herniation and Resultant Sciatica

The disc is a major source of pain within the low back. The dual nerve supply to the disc, involving both regular sensory nerves and those of the sympathetic system, results in more profound, diffuse, and complex pain.

'Slipped disc', 'herniated disc', 'sciatica', 'nerve damage' are terms used interchangeably and often inappropriately when dealing with low back and leg pain.

The disc comprises a tough outer shell (annulus fibrosus) and a soft inner core (nucleus pulposus). A weakness in the annulus fibrosus may allow the nucleus pulposus to bulge outward, while a tear of the annulus fibrosus will permit the nucleus pulposus to actually extrude from the disc.

Herniation often results from the gradual aging of the disc, combined with poor muscle strength and improper body mechanics. Due to the close proximity of the spinal nerve roots to the posterior aspect of the disc, herniated nucleus pulposus material can compress or stretch these structures. This may reslut in pain, typically 'sciatica' or nerve dysfunction with numbness or weakness in the leg. Seventy percent of patients with sciatica recover in 6 to 12 weeks.

Sciatica refers to pain in the leg below the level of the buttock fold. It relates to the sciatic nerve, a large nerve supplying most of the leg with power and sensation that arises from numerous roots in the lumbar spine. If the pain of sciatica is specific, relating clearly to one nerve root, then it is called radicular pain. Often accompanied by numbness or tingling, the pain radiates down the leg to a specific area such as the great toe or the outside of the foot.

If the pain of sciatica is more dull, radiating downward but to a more diffuse area, it is called referred pain. Typically, this pain radiates through the buttocks and thighs, sometimes into the calf.

Nerve root compression and damage can also cause the nerve to malfunction. In this case, there may be loss of the skin sensation in the area supplied by the nerve, loss of power in the muscles it supplies, and loss of reflexes as tested by an examiner. Nerve root dysunciton may or may not be associated with pain. Sciatica does not imply damange, just irritation - the nerve is usually able to recover.

2. Facet Joint Pain

The lumbar facet joints are the paired synovil joints at the back of each vertebra supplied by branches of the dorsal sensory nerve, the main trunk through which peripheral sensation reaches the spinal cord. Each facet is supplied by two nerves, one from its own level, one from the level above. The capsule of the joint is densely supplied with sensory endings that respond to pressure and stretch. It also contains specific pain fibers. Mechanical stimulation by chronic or acute strain of the joint capsuel can give rise to painful sensation, particularly in the presence of sensitization by local factors such as inflammation or by cnetral mechanisms.

The presence of nerve endings within the synovial tissue lining the facet joint prvides an additional source of painful stimuli. This would likely play an important role in arthritic conditions affecting the spine, such as rheumatoid arthritis, ankylosing spondylitis, or osteoarthirtis.

The facets are joints just like the knee or the shoulder joint. The surrounding capsule and ligaments can be stretche by movement or force beyond their tolerance, and the jont itself can become inflamed and swollen. The facet joint is a significant pain generator, often resulting in both local and referred pain, muscle spasm, reduced flexibility and tenderness. Next to muscle injury, facet strain is probably the second most common cause of acute low back pain.

One very helpful lower back pain management tool is the use of TENS which means Transcutaneous Electrical Nerve Stimulation.  Clearly written information on TENS can be found at http://www.queenwestphysio.ca/strategies/electrotherapy.html

Aside from pain arising from discs or facets, back pain origins also include pinched nerves and bony growths known as osteophytes.

Some possible external causes of lower back pain that can directly change the structures in your body, can include:

• Sudden injury to the back such as may occur in an auto accident, fall, sports, or other manner.
• Stress to the muscles, nerves, or ligaments in the lower back.
• Certain jobs such as those that require repetitive movements, sitting in chairs that are not ergonomically proper for your back, or standing for long periods of time often increase back stress and cause lower back pain.
• Arthritis, osteoporosis, osteoarthritis, and other bone or joint diseases often cause lower back pain.
• Not getting enough physical activity, being sedentary, or being overweight often stresses the lower back causing pain.
• Smoking history, hypertension, and coronary artery disease (risk factors for atherosclerosis, occlusion of the arteries) are significantly associated with development of lower back pain.