The Change from Acute to Chronic Back Pain

Chronic back pain is a very important and costly condition in advanced industrial societies which is the chief cause of limitation of physical function in younger people under 45. The definition of chronic is variable and can be taken to be a pain persisting beyond the expected healing time of the tissues which may have been damaged in the acute back pain event. This is often taken to be beyond twelve weeks as much of the soft tissue healing will have occurred at that point. Acute pain serves a biological purpose to warn us to stop doing the aggravating activity and to take care of the injured part, however chronic pain appears to have no useful function.

Low back pain is a common occurrence and up to 20% of a nation’s population may be affected by longer term or recurring bouts of pain without significant disability. Of the overall number with back pain problems around five to seven percent may fall into the severe category, exhibiting significant disability and inability to work. For this problem it is moderately frequent to employ surgical means and some of the delayed resolution of pain problems may be related to poor blood supply in spinal tissues.

Most back pain appears to be caused by traumatic events to the back or is secondary to degenerative changes which occur in the spinal discs and joints. The connection between the spinal pathology and the pain with which a patient is suffering is not completely clear as many disc prolapses and protrusions seen on MRI scanning are not symptomatic. There may be neurological and inflammatory reasons for back pain but these factors are not clear and so the pathology of low back pain overall is not well understood.

If imaging and other diagnostic studies do not reveal a plausible pathological reason for a person’s back pain then it is very easy to question whether psychological factors are responsible. Although psychological factors combine in a complex way in the progress from acute back pain towards a disabling condition there is no good evidence that psychological factors can produce pain. The cause of the pain may just not be amenable to the forms of investigation now prevalent. Once the condition is present or developing however, and arguably even in the acute stage, it is vital to identify and deal with all the non-physical factors to attain the best outcome.

Heavy workers make up the greatest preponderance of claims for low back pain, with high risk categories being truck drivers, operators of heavy equipment and construction workers. The lifetime prevalence of back pain and sciatica appears to be very high in heavy workers such as those working on road construction. Sciatica is much less common than back pain (around five percent) and typically resolves without interventions, but is still an important cause of surgical management with most surgery occurring at the L4/5 level, closely followed by L5/S1. Levels of surgical management are low in the United Kingdom but can be much higher elsewhere, such as in the United States.

It is in western industrialised countries that the levels of disability from chronic low back pain have become very high with typical social and economic consequences. No genetic factors have been distinguished between different races to explain the variation in causative mechanisms. The split between male and female sufferers is about equal and people report low back pain mostly in middle age when the large majority have evidence of spinal degenerative changes. Sciatica, closely related to disc changes, occurs mostly in the 30s and 40s with age 42 being the average age for lumbar discectomy.

The last and more flexible part of the spine is the lumbar spine which is specialised in supporting the weight of the body above it and in transmitting it to the legs. For its size the lumbar spine is able to manage heavy loads and pass them on through the sacroiliac joints to the pelvis and the legs. There is considerable mobility in the lumbar vertebrae and they function to transmit loads by the internal bony structure of the cancellous struts forming stronger areas called trabeculae which are aligned with the lines of forces taken by the spine in activities.

About the Author

Jonathan Blood Smyth is the Superintendent of Physiotherapists at an NHS hospital in the South-West of the UK. He writes articles about back pain, neck pain, and injury management. If you are looking for physiotherapists in bradford visit his website.