Lower Back Chronic Segmental Stiffness

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.

Protective muscle spasms are common after an injury and this splints the affected area and allows the process of inflammation and healing to get started. With the gradual resolution of the injury and its pain reduction the amount of back spasms normally lessens and slowly normal movements begin to be apparent again. But muscles can remain in muscle spasm in some cases, leading to a stiffened and shortened group of spinal structures which, by this adaptive shortening, leads to the production of shortened and abnormal spinal joints, ligaments and muscles.

Increase of the compression forces through the spine can be promoted by sitting for long periods, leading to increase in the fluid loss from the discs. Discs rely on us repeatedly bending forwards for disc health and nutrition and avoidance of this movement compromises disc wellbeing, leading to an increased potential risk of degenerative change. A weakness in the abdominal muscles and the development of abnormal postures also contribute to these problems.

Chronic segmental stiffness is usually indicated by a history of back pain and general backache with some leg referral also possible. Since many and variable areas of the spine can be stiff or mobile, the stiffness which contributes towards the painful problem might have been present for some time. The pain is worse on sitting for long periods or doing bent over activities, anything which stresses the stiff segment towards the end of its available range of motion. The facet joints become stuck in an extended position and the segment tightens up by adaptive shortening, losing its ability to flex or maintain flexion comfortably. My back problems are like this and can be quite troublesome on stressing, leading me to avoid heavy work such as lifting objects of any weight.

Sarah Key, a physiotherapist who is well known in the UK, has produced the Sarah Key's Back Sufferers Bible, a book in which she sets out her views of what is going on in this most common of musculoskeletal syndromes. She does acknowledge that it is hard to bring solid evidence for many of her interpretations but seems to have many good and practical therapy ideas to approach the back pain problem with. She covers the main syndromes which typically occur, giving treatment routines for self management of each one, all of which I have found very useful for my own lower back pain. Now I have something I can do about it rather than accept it as a fact of life.

Jonathan Blood Smyth, editor of the Physiotherapy Site, writes articles about Physiotherapists, physiotherapy, physiotherapists in Harpenden, back pain, orthopaedic conditions, neck pain and injury management. Jonathan is a superintendant physiotherapist at an NHS hospital in the South-West of the UK.