Pain is complex. We now understand that their are many inputs outside of localized tissue damage that contribute to the pain experience. In the last 10-15 years lots of good research and amazing writing has come out on the complex physiology of pain. It has changed the way we treat and manage pain for the better. In this post I review some of the important concepts from the 2003 breakthrough book, Explain Pain.

The initiation of pain

Pain occurs when the brain responds to stimulus from the rest of the body. It is constructed from combining signals from the emotional memory centres of the brain, the nerve endings in our skin (mechanical, chemical, and heat), the immune system and our nervous system.

The activation of mechanical, temperature, or chemical receptors within a neuron can initiate a nociceptive signal (danger signal). These signals are going all the time and only sometimes do they result in pain. Nociception is the most common precursor to pain, but thoughts, memories, and experience can also evoke pain and danger signals within the brain.  In Melzecks, body neuromatrix, he outlines the different internal and external inputs that contribute to our experience of pain.

Neuromatrix See here for more information:[/

Understanding pain

When we understand our pain it reduces the threat and improves our ability to manage it. Most of the time, the more we know the better off we are. In certain cases, over diagnosis through MRI and x-ray (SEE HERE) and the type of language used by a therapist, can negatively impact a persons experience.

As time passes tissue begins to heal. Pain that persists beyond 6-12 weeks is often more likely associated with nervous system sensitization than tissue breakdown. In persistent pain cases (pain for longer than 3 months) it is imperative to find out why the brain has come to the conclusion that you are always in danger. If we can identify these “ignition cues,” it is easier to move forward with the healing process.

The amount of pain you experience does not always relate to the amount of tissue damage. The terms disc bulge, degeneration, pinched and squashed nerves can all have a negative impact on the perceived pain experience. The over 60s have far less back pain, again showing us that degeneration and tissue changes are not always related to pain. Furthermore, pain relies on context. If a guitarist or violinist were to injury their fingers, they would most likely feel a lot more pain than someone who did not rely on their fingers for a living. You can also think of soldiers who do not notice a severed limb because they are fleeing other more imminent danger.

As physios it is our goal to help people feel comfortable moving again. Back pain sufferers often have a fear of bending forward. It is our job to work with our clients to find novel movements to allow the body to explore different positions that are non-threatening but still put the body into a bent position. It is our job to reduce the perceived threat and get our clients moving. Remember the body loves to movement! I will be writing another post on the importance of varied movement strategies shortly.

A stressed emotional state can further affect healing because of altered muscle tension and cellular processes. Pain can be far greater when our bodies are emotionally stressed due to work, relationships, or family.

Final Remarks

Whether it is back pain or knee pain, we now understand that we must look beyond just the damaged tissue. We must also pay close attention to the nervous system and clients beliefs, goals, motivation, fears and understanding of their injury.

Important Links

Link to Lorimer mosely Pain video:
Link to NOI group:

Explain Pain. Butler, D., Moseley, L., Sunyata. (2003). Noigroup publications