Pain in the Brain

By Nick Kinnear, 29th July 2022

This week is National Pain Week, and as part I wanted to talk about a book I often use to help educate people. The above image is from a book titled ‘Explain Pain’ written by two Australian researchers, Lorimer Moseley and David Butler. It may appear complex at first glance, but there are messages in this image that are important, particularly if you suffer from pain. This particular image is a good representation of how the body has changed with the presence of pain and how we aim to reverse or improve those changes

The main aim of the body is to keep itself alive, which forms the basis for pain. Pain is a signal sent to/from the brain to keep the body protected from perceived further damage. Pain does not necessarily equal tissue damage, which makes it a very complex process. When pain signals, or ‘danger sensors’ activate, this is the body trying its best to keep itself safe. After an injury or with the presence of chronic pain we will likely see these pain signals well before we reach capacity. There are a host of other factors that contribute to pain besides the stimulus we are feeling. To name a few life trauma, religion, diet, socio-economic status, and personal beliefs can change pain.

Let’s take a closer look at the top part of the image, with the two mountains representing the state of our bodies before and after injury. In the before injury image, both the ‘protect by pain’ and ‘tissue tolerance’ lines appear higher than after injury. This is important to understand, this is the body protecting itself from further injury.

If we look at the ‘after injury’ image, note how far apart the new ‘tissue tolerance’, and new ‘protect by pain’ line are. The body is trying to protect itself better (in the form of a pain signal) far before there is a threat to the tissue. It will even protect with pain before it reaches the flare-up line, meaning there is minimal threat to tissues but still presence of pain. This is due to our past experiences of injury, as injuries are often painful and not somewhere we want to return to. For this reason it can be challenging to find the balance to push ourselves into discomfort, even when it is often safe to.

So how do we use this to our advantage?

If we look at the ‘pacing & graded exposure’ part, this is a representation of how we want the body to progress. After a bout of exercise, the body adapts or repairs itself to become better placed to complete the same thing the next time we do it. For those presenting with pain, we want to start with things that feel easy, light or pain-free. Once we have found a baseline, exercises should then progress gradually, so that we are increasing the stimulus given to the body but not reaching our flare-up or protect by pain lines. Over time, and with appropriate programming, the protective mechanisms will adjust, so our capacity increases but the threat to our body is low.

Part of your pain journey is to retrain your pain system and convince your body it’s safe to move again, which can take some time. It’s important to be aware that as we increase strength and capacity, the sensitivity of the system reduces. We still have a protect by pain response but it increases with our new tissue tolerance.

Its also important to understand that pain isn’t always a negative response. The body needs pain so that we don’t walk around with nails in our feet, or bugs biting us. Yet, when it comes to recovering from injury or chronic pain, we can use pain research to educate ourselves and give us an advantage.


Butler, David S, Moseley, G. Lorimer & Butler, David S. 2013, Explain pain, 2. edn, Noigroup Publications, Adelaide, South Australia.