Most of us start off with a beautifully mobile and smooth running back and rarely are we stiff backed unless there is a reason for it. The back is well evolved to do the job it has to do and does this mostly very well. Spinal bones are separated from the vertebrae by discs which are thicker in areas of greater mobility and greater load, allowing more movement. Facet joints at the back of the spine limit and control spinal motion, stopping inappropriate spinal displacement in response to the loads placed on the spine. Muscles are strong, in balance and working in harmony to achieve the movement and stability required.
Inhibition of the stabilising musculature occurs with an episode of acute spinal pain and this can persist beyond the resolution of the pain to generate a long-lasting instability which puts the segment at increased risk of re-injury over time. Longer term effects include the occurrence of degenerative alterations in the spinal structures such as joints and discs, causing segmental levels to develop stiffness and eventually chronic back pain. The discs have fluid forced out of them by gravitational compression forces and must counteract them by generating a fluid absorption force.
As compression forces tend to be more powerful as time goes on, dehydration of the disc occurs to some extent as it narrows and stiffens. This can be imaged on x-ray but the disc is likely to show changes and painful problems long before the results can be seen on x-ray. A segment is defined as two adjacent vertebrae and the intervening intervertebral disc, an altered disc contributing to an abnormal segment which moves abnormally and pushes abnormal loads onto tissues where they are not designed to take them. Physiotherapists can feel the restrictions in spinal movements which occur when a stiff segment limits segmental excursion.
After an acute back pain injury the surrounding musculature tends to go into muscle spasms to splint and protect the injured segment until inflammation reduction and healing have had a chance to begin. Steady reduction in pain and progress in healing is usually accompanied by lessening of the back spasms and a restoration of normal spinal movement. However, this does not always occur as muscles may remain contracted and overprotective, causing a shortened tissue area which keeps the local joints and other tissues in a permanently shortened position.
Sitting for extended periods can increase the likelihood of suffering from increased compression of the lumbar discs with consequent fluid loss. Repeated flexion maintains the regular cycle of fluid uptake and avoidance of this movement interferes with this important process for disc health. The maintenance of abnormal posture and lack of strength in the abdominal muscles are also important factors.
Having a series of acute episodes of lumbago can predispose to developing a segmental stiffness problem, often with the stiff or abnormally moving segments of the spine having been present for a long period before they start to give pain symptoms. Actions which make this syndrome worse will tend to hold the spine in flexion for long periods or at end ranges, such as sitting for extended times and bending forwards repeatedly, actions which push joints further than their limits of comfort. The spinal facet joints develop an extension dysfunction and the spinal segment can become adaptively shortened, compromising its movement ability. My own lumbar spine has some of these back problems and limits my ability to do repeated lifting or bent over work.
However, I have been significantly improved by following Sarah Key’s method of back care, popularised in her book Sarah Key’s Back Sufferers Bible. While it is hard to agree with all the assertions she states in her book (as she herself admits), there is no doubt she has some very good ideas on how to practically manage low back pain. She describes the chronically stiff segmental back along with several other back pain syndromes and prescribes an exercise and management regime for treating them. The regime is not difficult but has very good results, particularly in my case where I felt I was stuck with my lower back pain and now realise this may not be the case.