Exercise Influences the Almond in the Brain
This is a pretty good paper published in 2015 presenting the studies supporting the notion that exercise therapy may be an effective method of helping individuals with persistent musculoskeletal pain.
At first reading, this seems like common sense but the authors propose that the benefits of exercise have little to do with increases in strength, flexibility or endurance or “fixing” a structure. The primary benefit of exercise or movement therapies for persistent pain is to influence the central nervous system and reduce the anticipated fears of movement.
Thanks to the Amygdala, patients with persistent pain are frequently limited in their activity levels due to protective pain memory. The Amygdala is the almond-shaped section located in the temporal lobe. It is part of the limbic system, which is responsible for emotions, survival instincts, and memory. Its name comes from the Greek word for almond.
The Amygdala modulates all of our reactions to events that are very important for our survival. When researchers have directly stimulated the Amygdalae of patients undergoing brain surgery, patients have reported most often of feeling imminent danger and fear.
In rare cases, where the Amygdala is destroyed (e.g. post-stroke), patients are able to recognize the facial expressions of every emotion except fear.
The Amygdala is therefore referred to as the fear-memory center of the brain and “remembers” the negative emotions related to pain; it has therefore been blamed for facilitating the development of chronic pain/central sensitization. (Note: chronic pain is much more complex than just one part of the brain; I have simplified it for the purpose of this review.)
The protective pain memories stored in the “almond” in our brain may continue to become stronger long after the injured tissues have healed, leading to chronic pain.
It is suggested that, as PTs, we can prescribe exercises and address movement related to pain memories by applying the “exposure without danger” principal. Daily exposure to a safe physical activity or movement will eventually convince the brain that it is not truly in danger.
The ultimate goal of PT is to provide pain neuroscience education in order to reduce the threat value of any exercise and movements provided. We must change the belief that pain always means tissue damage.
The paper makes a point that I strongly agree with, and that is: PTs must be cautious and not promote “inappropriate safety behaviours” such as teaching contraction of specific core muscles before bending or twisting and the teaching of maintaining neutral spine during low load physical activities.
With the best of intentions, PTs teaching patients inappropriate safety behaviours can increase their fear and perception that they are fragile. We must reduce the threat value of various activities and movements stored in the “almond” in their brain.
Reference: Nijs J et al Exercise therapy for chronic musculoskeletal pain: Innovation by altering pain memories. Man Ther. 2015 Feb;20(1):216-20.
