Rene Descartes suggested “If there´s damage, there´s pain, if there´s no damage therefore there´s no pain and the more damage you have, the more pain you feel”, suggesting that the degree of pain experienced was directly proportional to the degree of tissue damage, but… is that correct?
NO, ABSOLUTELY NO!
First of all we should know and understand what the pain is and according to the IASP (International Association for the Study of Pain) "Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage" (1).
After understanding that pain is not just a sensation but also an emotional experience associate with actual or potential damage, we should differentiate between two different types of pain which are Acute and Chronic.
Is the useful pain and it lasts no more than 6 months. It is the way the body lets you know that something may be wrong. For instance, when you sprain you ankle, quickly your brain realises that there is something wrong and sends painful signals in order to advise us that if we carry on running we could cause major damage.
Is when you feel pain for more than 6 months and after negative blood tests, X-Ray, MRI, etc, we find out that no damage could be found. This is because after 6 months we know that the healing process is complete and therefore this type of pain is not related with damage in the body and is not useful.
Chronic pain is usually unpredictable, this pain is not useful anymore as it is not telling you about any damage in your body
HOW IS THAT POSSIBLE? ... Let me tell you one good example.
Before i tell you, let me introduce you HOMUNCULUS, who is the body representation your brain has about the different parts of the body. Homuncular man’s proportions are determined by the relative sensitivity of each body part, as determined by the density of nerve endings in each part. Not surprisingly, tongue, lips, hands and face are all very sensitive areas, and accordingly have a greater number of nerve endings.
The best example could be the phantom limb pain, the pain someone experiences in an amputated limb after an amputation. If this limb still exists within the homunculus, even if that region isn’t physically there anymore, the patient refers pain in the amputated limb. There’s no limb anymore, but there’s pain in that area (2).
To sum up, our brain receives information from every single neuron and at the end it has to wonder: IS THIS DANGEROUS?
That´s the question the brain receives along with all the information and decides if that information is dangerous and therefore painful or it´s not dangerous and painless.
Our brain is full of memories, thoughts, feelings, information from other senses, our culture… and therefore all of these things make an impact on how we perceive the different signals. For instance if a violinist has an injury on their index finger, they will feel more pain than a footballer, because their finger is a bigger 'threat' for him than for a football player(3).
Sometimes the brain is confused;
Our brain perceives it as moving but… It isn’t.
The reason we feel the pain with no damage is because our nervous system becomes more sensitive, our pain threshold decreases and the brain receives much more messages from the nervous system concluding there is a DANGER!!
HOW CAN WE MANAGE THE CHRONIC PAIN?
We can reduce the sensitivity of the nervous system by:
Managing the anxiety
Pain education: Current evidence supports the use of pain neuroscience education for chronic MSK disorders in reducing pain and improving patient knowledge of pain, improving function and lowering disability, reducing psychosocial factors, enhancing movement, and minimizing healthcare utilization (4).
Physical activity: According to the available evidence physical activity did not cause harm (5).
1. IASP Taxonomy - IASP [Internet]. [cited 2017 Aug 16]. Available from: https://www.iasp-pain.org/Taxonomy
2. Nikolajsen L, Jensen TS. Phantom limb pain. Br J Anaesth. 2001 Jul;87(1):107–16.
3. Butler D, Moseley G. Explain Pain. Noigroup Publications, editor. Noigr Publ. 2nd Editio. Adelaide: Noigroup Publications; 2003;130.
4. Louw A, Zimney K, Puentedura EJ, Diener I. The efficacy of pain neuroscience education on musculoskeletal pain: A systematic review of the literature. Physiother Theory Pract. 2016 Jul 3;32(5):332–55.
5. Geneen LJ, Moore RA, Clarke C, Martin D, Colvin LA, Smith BH. Physical activity and exercise for chronic pain in adults: an overview of Cochrane Reviews. Geneen LJ, editor. Cochrane database Syst Rev. Chichester, UK: John Wiley & Sons, Ltd; 2017 Apr 24;4:CD011279.