Moving differently after injury may lead to chronic pain
Chronic Pain Development
When people suffer musculoskeletal pain – that is, pain arising from muscles, ligaments, bones or joints – they change the way they move. Changes may include completely avoiding certain movements, and despite being subtle. Someone with knee pain might walk with a limp, whereas someone with hand pain might pick up an object differently, while someone with neck pain might refrain from turning their head to one side. Does this contribute to chronic pain?
Our brains tell our bodies to change how we move and that change might contribute to the development of chronic pain that lasts for months or years. The change of movement pattern whether helpful or harmful depends on how long you have been experiencing pain. Can the way we move after trauma lead to chronic pain?
Acute vs Chronic Pain
When pain is short-lived (minutes to hours), changes in the way we move are thought to protect us from further injury by restricting movement of the damaged part. This important protective strategy mirrors the altered activity in our brains. A large body of evidence shows that short-term pain causes a reduction in activity in the regions of our brains that control movement. But for pain that lasts longer than a few days, a recent study has shown activity in the areas of our brain that control movement actually increases – the opposite of what happens with pain lasting minutes or hours.
This reflects your brain’s search for a new way to move, now that the pain is chronic or persistent. This new way of moving aims to maximise your performance of daily activities while reducing pain as much as possible. However, changes to the way we move that are helpful in the early stages of pain may have negative long-term consequences. For example, moving differently for a prolonged time will alter the loading on surrounding muscles, ligaments and joints, potentially adding more stress to the body region that was initially injured. This may then lead to persistent or recurrent pain, perhaps interspersed with only short periods that are pain-free.
So when the chronic pain has persisted for 25 months or years, are changes in movement still helpful?
Development of Chronic Pain
Evidence from several studies shows that people who have been experiencing pain for more than three months frequently use more simple ways of moving. For example, when climbing stairs, people with hip pain move their hips, trunk and pelvis differently to people without pain.
Those with persistent elbow pain, meanwhile, show changes in muscle coordination while gripping an object. These more simple ways of moving result in fewer peaks in brain activity than usual. This is similar to perfecting your tennis backhand, when the skill becomes more automatic. suggesting Simplified ways of moving might become ingrained in the brains of those with long-term pain.
Importantly, changes in movement persist in people who have recurring episodes of pain, even when these people are pain-free. As a result, moving differently, even when free of pain, could predispose you to another pain episode. We need more research to confirm this link as it is clear that there is a relationship between movement and pain.
Managing Chronic Pain
Treatments retrain the way we move, such as physical activity and exercise, are the cornerstone of management in musculoskeletal pain. The type, duration and quantity of activity or exercise needed to promote recovery from pain are unclear. We know that moving too little or too much can each have negative consequences for people in pain.
We need more research to understand exactly why people move differently when in pain, and how we can use this to treat or perhaps even prevent persistent pain in future.
Reproduced from PhysioTimes magazine. Jan 2017