The Evolution of Low Back Pain
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Chapter 2.2 The Sublesation
Although the idea of a warning pain explains some aspects of back pain it does not explain the muscular spasms that are so often associated with back pain.
It seems very likely that these muscular effects are associated with a phenomenon that occurs in the spine of any animal that I shall refer to as a sublesation. The chiropractor refers to this effect as a chiropractic subluxation and the osteopath refers to it as an osteopathic lesion.. I shall avoid both words because in medical terms it is neither a subluxation nor a lesion because it is within the normal range of joint mobility and because there is no associated tissue damage. (Osteopaths have recognised this and now call it a somatic dysfunction.)
I have also avoided the word fixation because this includes cases where the joint is fixated by adhesion following trauma. The word sublesation should avoid all these ambiguities because it doesn't exist. It is a combination of the chiropractic term subluxation and the osteopathic term lesion. I hope that sublesation will eventually be accepted by both professions and also by the medical profession so that this important phenomenon can receive the recognition and research effort that it deserves.
In a sublesation local muscles around a joint are permanently energised by nerves that are in some way excited by the clamping effect of the muscles. Thus the effect is self- perpetuating. The mobility of the joint is greatly reduced and it is distorted asymmetrically because the muscle in spasm is only on one side. The osteopath and chiropractor both recognise the characteristics of the sublesation as asymmetry, loss of mobility and local muscle abnormality. The effect can occur in any spinal joint of any animal and has probably evolved in order to allow an injured joint to recover. (This phenomenon is the central point of chiropractic and is also central to osteopathy.)
When the warning pain has been triggered and there is disc damage or potential disc damage, the sublesation is ideally suited to provide muscular immobilisation of the vulnerable part of the spine. It seems likely that the phenomenon of the sublesation has evolved to be a very much more powerful effect in the human lumbo-sacral area. It also seems likely that evolution has used sublesations in the pelvis and sacro-iliac joints to cause muscle contraction in many of the muscles of the lumbar region. (It is also possible that the warning pain directly energises some muscles. Regardless of how large muscles are energised and put into spasm, the balance of most muscles of the pelvic region is bound to be disrupted). Where parts of the erector-spinae and the psoas are involved the lumbar spine can be very effectively splinted or immobilised.
Some characteristics of this sublesation should be noted;
1) It is triggered by the warning pain from the disc but may possibly be triggered by other strains as well.
2) It is self-perpetuating so it will remain after the triggering pain from the disc has gone away.
3) It probably causes pain because this would be advantageous in inhibiting actions that might injure the weakened disc again.
4) The loop that perpetuates the sublesation would normally be released eventually by exercise.
5) Osteopaths and chiropractors have developed methods of releasing the loop by fast manipulation. They use high velocity, low amplitude thrusts to move joints before muscles can react. This releases the clamping effect for long enough to interrupt the stream of nerve impulses from the joint and this breaks the nerve loop that is clamping the joint. Physiotherapists use other forms of manipulation. Massage of the muscle can probably have the same effect.
6) The phenomenon of the sublesation is reasonably well researched inside the osteopathic profession. It is referred to as the osteopathic lesion or somatic dysfunction and is associated with the facilitated segment (Chapter 2.3). Confusion may be created by my invention of the new term sublesation but even more confusion has been created by the wrong use of ‘ lesion’ and ‘ subluxation’.
There are many theories about the nature of the sublesation. The interpretation given here comes mainly from Osteopathic research ( mainly Korr) and from other papers, researchers and practitioners.
This interpretation seems to be the only one that corresponds to the facts and particularly to the way in which sublesations can be switched on by some occurrence at a different point in the spine. This could not occur with a fixation caused by adhesions or tight ligaments. However, if a joint remains immobile for a long time these other restrictions on mobility will obviously develop.
(My conclusion from various sources is that the sublesation is almost certainly a unilateral spasm of the Rotatores muscle in the thoracic area and therefore probably of the laminar fibres of the Multifidus in the lumbar region since they are homologous to the Rotatores.
I was interested to find recently that the Australian writers on core stability concentrate on exactly these parts of the multifidus.