How to "flatten" low back pain
LBP is most common in the 40 to 70 year old age group. Up to 90 per cent of people will have an episode of low back pain at some point in their lives. While most patients will recover from their incident, approximately ten per cent will go on to develop chronic low back problems. The amount of money spent on low back pain, including the cost of treatment, legal, and economic (days lost from work, etc.) is enormous and estimates run to as high as 30 billion dollars annually. While the cause of low back pain is usually a benign process, it is important to eliminate the more serious causes of low back pain such as tumor, infection, aortic aneurysm, or fracture. The low back is comprised of a stack of vertebrae, each separated from the other by a disc containing a gel that acts as a cushion. The vertebrae and discs are supported by a complex series of muscles, ligaments, and tendons. Helping to further cushion these structures is a group of bursae (fluid-filled sacs). Finally, the spinal cord runs down through a central canal in the vertebral column. At each disc level, the spinal cord sends out a pair of nerve roots- one to each side. These nerve roots provide the innervation for the structures in the hips and legs. Low back pain is caused by a number of different problems including trauma, inflammation, degenerative and mechanical processes, infection, and malignancies. Approximately 90 per cent of patients have a mechanical problem accounting for their low pack pain. The history is important because it can point out symptoms that might suggest causes of low back pain that are not degenerative. In most cases, though, a history of trauma, repetitive motion, or other activity is elicited. Sometimes the inciting episode is relatively trivial. A patient may state they were “just brushing my teeth”, or “just bending over to pick up the newspaper.” It is this type of history that will point towards low back strain being the culprit. Strain refers to pain due to unexpected stretching of muscles or nerves. Multiple reasons are responsible for strain including repetitive motion, unexpected movements, lifting, rotating/twisting of the trunk, or even emotional stress. Physical examination will reveal limited range of motion, significant muscle spasm, and tenderness of the muscles that lie alongside the spine. Factors predisposing to strain include occupations or hobbies that cause repetitive motion in the low back, obesity, deconditioning, poor posture, prolonged exposure to vibration (heavy equipment operators). Another key point is that the low back shares an interdependence with the hips, knees, ankles and feet. So... any problem occurring lower down will eventually lead to low back problems. An example would be a patient with a significant leg length discrepancy. Structures in the spine that are often responsible for pain syndromes are the discs and the facet joints. The discs can herniate – i.e., the gel inside the disc explodes out and causes pressure on the nerve root. The discs can also degenerate and cause nerve root pressure. The facet joints which interact in the back part of the spine can develop arthritis and cause nerve root irritation as well. Significant arthritis in the spine either in the facet joints or in the disc can lead to narrowing of the spinal canal – a condition called spinal stenosis. Spinal stenosis pain is aggravated by standing, walking, or extension of the spine. Sciatica is pain that radiates into the buttock and down the outside of the leg. This is due to pressure on a nerve root from either disc disease or arthritis in the fact joint... or both. Sciatica due to disc herniation is aggravated by sitting or bending forward. Sometimes low back pain will radiate down the front of the thigh. It is important to rule out hip disease, inguinal hernia, pressure on the femoral nerve, aneurysm of the aorta, and kidney disease. Some other unusual symptoms that are a tip off to more serious problems include pain at night that interferes with sleep (malignancy), pain and stiffness in the morning (ankylosing spondylitis), pain accompanied by fever or weight loss (infection or tumor), back pain accompanied by numbness in a “saddle distribution” and loss of bladder/bowel control (cauda equina syndrome – pressure on all the nerve roots in the lower part of the spine- this is a surgical emergency!) Physical examination should evaluate range of motion, the presence or absence of muscle spasm, the presence or absence of nerve root compression signs, deep tendon reflexes, and muscle strength. A careful examination of organ systems is mandatory to exclude the less common causes of low back pain in patients where the history is suspicious. The laboratory is not particularly useful other than to help exclude systemic causes of low back pain. Electrical testing can determine the presence of radiculopathy (pinched nerve). X-rays are not that helpful. Most low back syndromes don’t have readily apparent x-ray findings, and the majority of older patients will have x-ray abnormalities that are not symptomatic. CAT scanning and magnetic resonance imaging are more sensitive and specific. Low back pain treatment is highly dependent on diagnosis. For the 90 per cent of patients who have mechanical low back pain, a number of modalities have merit. For acute low back syndromes, bed rest for 24 to 48 hours may be helpful. No longer... since prolonged bed rest is actually detrimental. Aggressive physical therapy is often helpful. Spinal manipulation (chiropractic) may be beneficial as well. Specific stretching and strengthening exercises accompanied by non impact aerobic exercise is one of the most helpful modalities. Anti inflammatory drugs and muscle relaxants are helpful in alleviating symptoms. For patients with more chronic problems, a number of modalities have been used with varying degrees of success. Soft tissue and epidural injections are often helpful. Transcutaneous electrical nerve stimulation (TENS) has also found advocates. More recently, intervertebral disc decompression (IDD), a non-invasive, non surgical method for stretching and decompressing the spine has been shown in at least one study to achieve a success rate of 86 per cent. Recent studies have also shown botulinum toxin injections may be helpful for patients with mechanical back problems associated with muscle spasm. Surgery is indicated for patients who have intractable pain with a well-defined anatomic reason for the pain and who have a progressive neurological deficit.
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