We all get it. Most of us have had an injury that has settled at some point, but for some pain hangs around longer than we would expect. Why does this occur? And when it does, what can be done? In this article, Musculoskeletal Physiotherapist Mike Callan will talk about pain; how it works, factors that can affect how much pain we feel, and strategies for those who suffer with persisting pain.
Pain is well, a pain. But what is it exactly? An emotion? Physical damage in the body? In reality it is much more. Pain is a complex psychological experience that is different for each person. The experience of pain occurs when your body’s alarm system alerts the brain to actual or potential tissue damage. There is no such thing as pain nerves in our bodies. We have millions of detectors in our body known as nociceptors, which are located in skin, muscle, bone, joint, ligament, blood vessel, disc, and nerve. When stimulated, these detectors can send signals through our nerves to our spinal cord, then on to the brain. But these are not inherently painful. The messages sent from the receptors and nerves are just a ‘danger’ signals; the brain then decides whether or not we experiencing pain, and how strongly we feel it based on how threatening the signal is.
Making matters more complex, the brain and nervous system can get better at detecting danger and feeling pain the longer pain persists. Just like we learn a new skill like piano and get better the more we practise, the brain can get better at feeling pain, and can get better at detecting danger by making more neurotransmitters and receptors in the nervous system. This is how the pain system becomes more sensitive and easier to trigger. But hope is not lost! The same processes that allow us to feel pain more easily over time can also work in the reverse process. The brain and nervous system can be de-sensitised over time with a number of strategies that will be discussed below.
As there are two sides to a coin, there are two sides to the pain system in the body. There is a detection system and a pain-dulling system. This complicated pain-dulling system is strengthened when we exercise, get a good night’s sleep, are in a better mood, and when we have manual therapy.
The body’s pain system is constantly changing. The amount of pain we feel at any given time is much like the volume on our TV. If the pain system is very sensitive, the volume is on high. Every conversation is like shouting, and that action scene is almost deafening. Vice versa, when the volume is turned down, we might not hear conversations at all and the action scene might not make that much noise. Factors that can alter our perception of pain (changing the volume) include: sleep, mood, stress, exercise, previous pain experience, upbringing and beliefs around pain, anxiety, depression, fear of pain or injury, and hypervigilance (paying too much attention to pain).
Additionally, genetics can play a role in how much pain we feel. Research has shown that individuals with fibromyalgia, irritable bowel syndrome (IBS), chronic jaw pain (TMJ), and chronic tension headache may be genetically pre-disposed to having a more sensitive pain system. Individuals with these co-existing conditions should be made aware of this to allow more appropriate pain management.
For those who have persistent pain, there are currently evidence-based strategies to help manage pain.
Butler, David S. and Moseley, G. Lorimer Explain Pain
First edition 2003. Published by Noigroup Publications for NOI Australasia, Pty Ltd.