APA Pain Physiotherapist Matt Forster.
Pain is a complex and distressing human experience. Historically, pain was thought of as a direct measure of tissue damage. The French philosopher Rene Descartes in the 17th century described pain as a result of fluid moving through tubes from the injury to the brain, and related the process to ringing the church bell – once the rope is pulled, the bell rings in proportion to the force.
However, scientific research has advanced our understanding of pain. In recent years, some pain experts have been spending their time during a cold and rainy European winter, arguing about how to best define pain. They decided that pain is, a distressing experience associated with actual or potential tissue damage with sensory, emotional, cognitive, and social components.
This definition raises the thought that there might be a number of factors that can contribute to pain. It seems that Rene Descartes’s idea of pain as a measure of tissue damage did not explain the complexity of pain.
Take (fictional patient) Nathan for example. Nathan is 39 and strained his back moving pallets on the family pineapple farm on the Sunshine Coast. He had only just taken over the running of the farm from his old man. Six months later, Nathan had persistent pain. He was managing the farm, but mainly from the office, and could not do any manual work, or operate any machinery. He wanted to be a “hands on” farmer and work with the staff. He felt depressed, had gained weight, and had trouble sleeping. He felt that he had let his old man down and would not be able to run the farm like he had.
Nathan had been told that he may have to learn to live with his pain. However, a physiotherapist with knowledge about modern pain science helped Nathan identify which mechanisms were contributing to his pain. Maybe there is a fluid filled tube in there somewhere, but more likely there may be:
- Structural Mechanisms – Nathan was initially correctly diagnosed with a musculoskeletal strain, which can cause acute (short term) pain. He went on to have an MRI scan which showed a mild broad-based disc bulge. However, scans can often reveal “age related pathology” which in Nathan’s case, may not have been caused by the injury. This strain will take six to twelve weeks to heal, and the disc bulge will likely remain unchanged during this time. There may be stiffness and weakness in the tissues after the healing time frame ends.
- Nerve function mechanisms – The perception of pain requires information to be transmitted from the injured area via nerves to the brain (no brain, no pain). Unlike Descartes’s understanding, the functioning of the nerve system can vary. In some pain conditions, known as nociplastic pain, the sensitivity of the nerves near the injury can increase, and nerve transmission becomes more efficient . With this nociplastic pain, movements that are not dangerous and potentially helpful to the tissues, will be felt as significantly more painful than expected.
- Psychological mechanisms – By definition, pain is an emotional experience. Modern brain scanning techniques have shown that multiple regions of the brain process information about pain. The limbic system, which is in part responsible for processing of our emotions, is active when people are in pain. Pain can be associated with mental health conditions such as depression and stress. In Nathan’s case, he is fearful about further injury, anxious, depressed, and concerned his pain will continue. He became hypervigilant, avoided movements he fears might harm his back, and lost confidence in his back. This impacted on his family life, his work life, his relationships and his participation in hobbies and sports.
- Movement mechanisms – Due to the initial injury, Nathan lost mobility and strength in the injured area. After receiving the results of his scan, he became worried and fearful of his back, and start moving less as an attempt to avoid further injury. He felt stiffness and tension in his muscles due to trying to keep his back supported. He felt pains in other areas, changed how he gets up and down from a chair, and noticed an occasional limp. These abnormal movements can end up actually contributing to ongoing pain, rather that helping to prevent further injury.
- Health and lifestyle mechanisms – Six months down the track, Nathan has stopped exercising, he cannot drive the tractor, is staying in the office, and is now lying down a few times a day. He is having trouble sleeping at night, feeling depressed and not seeing his mates on the weekend. He has lost interest in restoring his ‘74 Harley and can’t see himself recovering.
Nathan’s case is not extreme or unusual. There are many Nathan’s out there, and it is important to recognise that his pain is not “all in his head”. However, there are multiple mechanisms contributing to ongoing pain. If treatment focuses solely on the disc bulge visible on his scan the outcome for Nathan will not likely be optimal.
Fortunately, Nathan has a great physiotherapist who has been able to identify all these mechanisms and develop with him a rehabilitation plan. The physiotherapist has a framework to help guide Nathan’s recovery. One framework developed by researcher Dr Bronwyn Thompson, describes three components:
- Making sense – Nathan’s physiotherapist was able to explain stiffness and weakness after the lumbar strain, that his disc bulge was not a major factor, and how his nerve sensitivity caused some increased perception of pain. Nathan was reassured that he was safe to move and would not cause more damage.
- Deciding – Nathan identified some goals he wanted to achieve. He wanted to help with harvesting, do more work on the Harley, and help out with his daughter’s basketball coaching. He decided to talk to his GP to try to reduce his pain medications. With the physiotherapists help, an exercise rehabilitation program was set up and Nathan started walking each day with his Hungarian Vizsla.
- Flexibly persisting – Nathan steadily made progress, but it was not a straight- line recovery. There were a few flare-ups along the way, some from trying too much too soon (movement factors), but others due to stress and anxiety related to the farm (psychosocial factors). He found that a bad sleep led to worse pain the next day (lifestyle factors). Some psychology treatment was recommended and Nathan found that learning some strategies to manage anxiety, improve his sleep and actively relax his muscles was very helpful to manage his symptoms and for his recovery.
Recovering from persistent pain is challenging. Finding the right physiotherapist who can work alongside patients to understand their individual pain mechanisms and provide a structured treatment framework is crucial to successful recovery. Nathan is now back on the farm pulling out pineapples again and taking his Harley for a cruise in the hinterland on the weekend.
Blog post written by Matt Forster (APA Pain Physiotherapist and QSMC consultant) for National Pain Week 2020. For more information on National Pain Week, visit www.nationalpainweek.org.au.