Pain is one of the few common experiences we can all relate to. Everyone has experienced pain at one time or another in their lives. No one enjoys being in pain, but it is a necessary part of helping keep us alive. To gain a deeper understanding of pain we will look at the various parts of the brain that control pain.
Pain is defined as “an unpleasant sensory and emotional experience that is associated with actual or potential tissue damage” which was developed by the International Association for the Study of Pain. Pain is an output from the brain when the brain thinks we are threatened. Tissues (muscles, joints, ligaments, and nerves) are just one input for the brain. The brain receives millions of inputs every second before it determines the output (pain or no pain) and processes them at an incredibly rapid rate, millions per second.
These inputs are messages sent to the spinal cord and brain, letting the brain know about temperature (so you know whether to wear a tank top or winter coat), blood flow (is it time to get up and move?), stress levels (hormones including adrenaline and cortisol), movement (your eyes are moving as you read this), and the immune system (such as when you have the flu). If the brain determines that something is a threat it can make you feel pain even in the absence of tissue damage. Processing pain is much more complicated than just a tissue being damaged, so let’s take a deeper look.
Scientists once thought that when tissues are damaged a special “pain center” in our brain lights up telling us we have pain and when tissues are healed this area turns off. We now know through brain scans that when we experience pain, nine areas of our brain light up, we call this our neuromatrix. Everyone experiences pain differently, my pain is different from your pain and your pain is different than your neighbor’s pain but we all have the same nine areas light up, they just light up differently. So what are the nine areas, what are they responsible for, and most importantly why does the neuromatrix matter?
- Premotor/Motor Cortex – organizes and prepares us for movement
- Cingulate Cortex – concentration and focus
- Prefrontal Cortex – problem solving and memory
- Amygdala – fear and addiction
- Sensory Cortex – sensory discrimination
- Hypothalamus/Thalamus – response to stress and motivation
- Cerebellum – movement and cognition
- Hippocampus – memory and fear conditioning
- Spinal Cord – first stop to process information from peripheral inputs (tissues) before sending the info up to the brain
Understanding that there are several areas of the brain that control pain is important. We now know that these nine areas do not just light up together when we experience pain but also communicate with each other when we experience other events such as memories and coordinating movement. This helps explain why when some people experience pain for prolonged periods they report difficulty concentrating at work, feel more stress, have a harder time completing physical activities, or can experience pain without tissue damage.
The good news: we can change the way that our brains light up through treatment interventions used in physical therapy. Education, manual therapy, trigger point dry needling, physical activity, and modalities are all ways that physical therapists can modify brain inputs to help people experience less pain and increase our ability to perform functional activities.
If you’re in pain, don’t wait any longer! Click here to make an appointment at your nearest clinic.
Ted Carter, PT, DPT, OCS, TPS, CSCS, Cert. DN
Foothills Sports Medicine Physical Therapy
Can virtual reality and dual tasking be part of your ACL rehabilitation? Yes, your ACL and other rehabs can incorporate virtual reality activities at all phases of the rehabilitation process as well as dual-task activities in order to be more successful.
Okay, here’s a couple of quick definitions:
- Virtual Reality Exercises: Doing any exercise with those cool VR glasses on that either makes your eyes see one thing in the glasses while you do something else or, has you follow a game while doing an exercise.
- Dual Tasking: You do an exercise while your brain is asked to do something else at the same time. For example, do a squat while you count backward by 5, name as many state capitals as possible, or have a ball thrown at you that you have to catch.
Injuries, such as ACL injuries often occur due to sensory-motor dysfunction.
We play sports in complex environments that have mental distractors that create great cognitive demand. Reviewing video analysis of ACL injuries there is a neuromuscular breakdown and a cognitive overload where the body is not able to adapt to the position and speed of loading. It becomes clear that there are pre-habilitation and rehabilitation programs that need to be better by increasing cognitive demand. We can even argue that by not increasing the cognitive demand with activity, we set patients up for failure. Once they are thrown back into a visually complex environment with their sport, they have not been trained to deal with it, and are therefore at risk for re-injury.
We realize that one of the growing areas of current and future research to improve our body’s function is cognitive research.
For years in rehabilitation after a major injury, many of the exercises that have been done in traditional rehabilitation are boring, and not mentally engaging. Recent research on brain activity during simple, learned exercise shows that once an exercise becomes easy, our brains pretty much turn off. There is some activity in the motor and visual areas of the brain, but very little. This results in ultimately less carry over to real-life activity. However, when the same simple task is done while in a virtual reality world or with dual tasking, the brain is firing all over the place. That motor activity is tied to a large amount of brain input and visual focus is taken off the injured limb, even as it continues to have to work to do the exercise. This improves what we call neuroplasticity, where we increase neural efficiency and increase neural support cells to help the body create improved neuromuscular programs with activities. Pretty cool, and kind of sounds like the real world and sport activity.
Even cooler is what was found when two groups of post-op anterior cruciate ligament reconstruction (ACL) patients were tested on their neuromuscular control (ability to control their knee, hip, and ankle as they squat) after a step-down task.
The group that trained with VR during the step-down task significantly improved their neuromuscular control relative to the non-VR group. In other words, by using virtual reality to engage more of their brain during exercise, when virtual reality was taken away and both groups did the same exercise, the group that engaged more of their brain during the rehabilitation exercise was more successful performing it after training. They had significantly improved more limb control than the non-VR group.
What does this tell us?
It shows us a patient’s brain gets bored doing a simple, unchallenging activity that only causes them to use the vision and motor centers of the brain. Virtual Reality or dual-tasking with exercise stimulates far more of the brain with even simple tasks that then make them more successful with complex, sport and life-like tasks. These results and the contribution of the brain to rehabilitation are seen in significant research by Grooms, Diekfuss, Lepley, Rausch, Kim, Monfort and many others when you explore the current literature.
This further shows us…
that in the rehabilitation of complex surgical cases like an anterior cruciate ligament reconstruction, the body craves neurological input to the new ACL and the surrounding muscles. That ACL needs all the help it can get from muscles that are actively engaged and from neuromuscular programs that are developed early in the rehabilitation process. This then can be carried over to later phases of rehabilitation when we are asking the athlete and patient to do dynamic activities such as their sport with balls and people flying around them, while still safely controlling what their knee is doing during the activity.
Virtual reality integration with exercise can be implemented by a skilled practitioner in a comprehensive rehab program that is done safely at the right point of rehab. This can begin the first-week post-op in order to stimulate improvements in neuromuscular control over those not using VR with the same exercises.
Learn more and schedule a free pain assessment with a Foothills clinic near you to #GetYourMoveBack.