I spent Saturday and Sunday at St Leonards Hospital in east London on a course which is simply titled Explain Pain. This approach to pain management is the brain child of two Australians, David Butler and Lorimer Moseley who founded the Neuro-Orthopaedic Institute. There were about 40 or 50 of us on the course, mostly physiotherapists (I was the only osteopath), all eager to learn about managing chronic pain. One of the central tenets of the Explain Pain approach to pain management is that when someone experiences severe pain, understanding the mechanisms that determine how much pain we feel is the best way of getting the pain under control.
Perhaps the most important thing to understand about pain is that it only exists in the brain. We do not have pain receptors anywhere in our bodies – the nerves which carry so-called pain signals are “nociceptors”. In plain English that means harm sensors (“noci” is the Latin word for harm). These signals travel to the spinal cord, where they communicate with “second order” neurones which carry the signal on to the brain (represented in blue in the image below) and it is the brain which decides whether or not to construct an experience of pain. This construction of pain is influenced by many other factors including:
- the current situation: “is it safe to stop and attend to the injured part or is it imperative to get out of a dangerous situation?”
- previous experience, eg “what happened last time I had this harm sensation?”
- beliefs, such as “my uncle needed a hip replacement so I probably will too.”
Some of these thoughts and beliefs are helpful. For instance it is not sensible to stop and rub your leg where you fell over a fallen branch if you are being pursued by a predator, or if you are trying to escape enemy gunfire. On the other hand if you are somewhere safe and you can see blood pouring from your leg, severe pain will get your attention and make you do something about it before it becomes life threatening.
However in many cases, the thoughts and beliefs are counter-productive. Many patients with low back pain have heard stories about people with sciatica and the awful things that happened to them: wheelchairs, surgery, etc. Being frightened by your pain has the effect of making it shout louder. Unfortunately when people hurt a lot they tend to stop doing anything that they believe may make their condition worse, whereas movement and activity are essential for tissue repair and will help to reduce pain levels.
So how do beliefs and fears affect the level of pain we experience? Nociceptors (the harm receptors, remember) communicate with other nerves in the spinal cord, in an area called the dorsal horn. The point where two nerves meet is called a synapse, and the dorsal horn is full of nerves which synapse with the nociceptor, all serving to either increase the signal or dampen it down. Some of this signal modification is due to activity in nerves coming down to the dorsal horn from the brain (represented in green in the image). The nerves which carry the signal on up to the brain are called second order neurones, but they only fire if enough of a signal crosses the synapse at the dorsal horn. So there may be situations where someone is injured but feels no pain because of inhibition from the brain. On the other hand in certain conditions including fibromyalgia and phantom limb pain, there is no tissue injury at all, but the nociceptors fire because of sensitisation from the central nervous system.
The Explain Pain approach aims to reduce pain levels in patients by working on the fears and beliefs which lead to sensitisation. On Sunday we were introduced to the Protectometer, which helps patients to rethink their pain and to begin to identify things in their lives which can help to reduce sensitisation, and as David Butler says, understanding your pain is the best pain-relief you can get. Understanding and a positive approach help to unlock the natural pain-killers in your brain, which get to work on reducing sensitivity in the dorsal horn and even in the nociceptors themselves.
I plan to take this work further. In November I am booked onto another course Explain Pain course which will introduce other methods of working with people with persistent and intractable pain. And in the new year I plan to start offering workshops and a chronic pain programme using concepts from Explain Pain and from OsteoMAP, which combines osteopathy with mindfulness and ACT (Acceptance and Commitment Therapy).
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Sorrel Pindar, Registered Osteopath and Clinic Director