Read part one of pain section first or this may not make sense. Why is it that so many people with lower back problems have minimal tissue damage yet suffer terribly? Its all to do with our minds.
It helps to have an understanding of more modern thinking. Aware of the inadequacy of the Cartesian (Descartes) model the IASP (see references) sought a clearer definition which took into account our new understanding. This is their definition:
“Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage (1) ”
Check out my italics – it is an emotional experience associated not just with actual tissue injury but with potential tissue damage. You can get painful sensations even when you haven’t injured yourself.
This is a very different way of looking at the whole experience isn't it?
We understand now that unpleasant sensations are interpreted by the mind. The brain gets signals from the tissues, samples them and decides if the information it is receiving poses a real or potential threat. If it decides there is a threat then painful sensations are experienced and we take appropriate action, we pull our hands away from heat, we rest our sprained ankle for a day or two, we yell and hop about when we step on a thorn.
However, if the brain samples the information and decides the threat is unimportant or there are other greater threats to worry about, it will ignore it or deliberately reduce and quieten down the signals it is getting.
For example you may sprain your ankle but you wouldn’t stop to rest it if you are being chased by a bear,
You wouldn’t yell and hop about with a thorn in your toe if you are stood on the edge of a precipice. If you are a victim of a shark attack the priority is to get out of the water, feeling extreme sensations and responding to that would be inappropriate and may lead to far worse consequences! The brain does this by releasing the bodies own perfect pain killer - endorphins.
we understand that pain is situational and open to interpretation all the time. It is not consistent.
This is a fantastic, brilliant system. The discomfort keep us safe, it does its job and it looks after us. Most of the time it works superbly well; we rest when we need to and keep ourselves safe from harmful encounters.
The problem arises when the brain gets it a bit wrong.
Tissues nearly always heal and so any sprains or strains have been normally repaired by scar tissue usually within about 6 weeks . (There is the very odd exception to this but it is rare and only involves people with delayed or altered tissue healing)
Sometimes though the brain doesn't realise this. It continues to focus attention and alarm on the sore area.
We know that the nervous system, including the brain, far from being fixed or ‘hard wired’ like the electricity circuit in your home is actually very flexible. It can and does change and adapt very quickly to different situations and environments.
This is the nub of the problem because when the brain perceives the sensation to be serious and a threat and focuses all its attention on it, changes can occur in the actual physical make up of the nervous system which can amplify the feelings.
These changes have been seen in the nerves, in the spinal cord and in the brain. All of them are designed to magnify the signal as the brain thinks there is a serious threat and wants you to pay very good attention to it in order to protect yourself from what it thinks will be further harm or danger.
Unfortunately, because we often believe that pain is a reliable sign of tissue damage we respond to this increasing pain by becoming anxious and focused on the problem. This causes a further increase in our symptoms which makes us more certain there is serious damage, and a vicious circle develops as below. This is called central sensitisation.
It’s a bit like a burglar alarm. When it works properly it comes on when it detects an intruder in the house. If it starts to become oversensitive it starts going off when the cat walks across the room, more sensitivity causes it to fire up when a sheet of paper moves, eventually the smallest of breezes gets those alarm bells going.
Imagine if the burglar alarm could change its volume too?
So to start with it makes a bit of a noise to warn that something is amiss, by the end of this process of over sensitisation it’s at a hundred decibels, deafening and drowning out everything else just because a speck of dust has passed in front of it.
This happens with some peoples nervous systems. Sensations that would have once been considered unimportant by the nervous system and brain suddenly represent full on alarm, danger and panic – and pain. It drowns out everything else. This is the cause of chronic pain – sensations that have lasted beyond the normal healing time of injured tissues.
The sorts of changes that have been observed in a sensitised nervous system are complex and a detailed explanation is beyond the scope of this web site.
If you want to read more about this highly complex , clever system I suggest you read ‘Explain Pain’(2) which is a highly readable and very informative book.
What does this all mean to us as people experiencing back problems?
Some days a feeling once regarded as normal, such as touch or movement, may cause severe discomfort. Sometimes even the skin over the area is sore, even though you can see in the mirror that the skin is unharmed. Other times just thinking about moving hurts, simple things that were once symptom free suddenly become very sore and difficult.
It means that a sensation felt as small on one day may feel severe on the next. Have you noticed this with your back problem?
This is not necessarily because the back problem has worsened or is progressing. It is really important to understand that the amount of discomfort you may be feeling may be unrelated to the extent of the injury. It is a symptom of a sensitised nervous system.
This *book is the MOST helpful book on pain that I have ever read. It is simple to understand and very reassuring. I would highly recommend it to anyone who is dealing with back pain.
1. IASP 2006 Available from: http://www.iasp-pain.org/
2.David Butler LM. Explain Pain. Adelaide: Noigroup Publications; 2003
Some of our fears and worries can make this more of a problem and make it harder to get back in control of the problem. These are called psychosocial yellow flags, but before you read about them I would recommend you read this section on the biopsychosocial model of pain.