Sensory Motor Amnesia describes a loss of awareness of a particular pattern of muscular activation to complete a certain task. This becomes habitual and often falls below a person’s level of awareness. We know that when someone sprains an ankle and they develop a limp, that new motor pattern of a limp can be very difficult to get rid of again. This happens because a smudge in their previous map of walking occurs when they limp. The ankle heals, but the limp remains. They have changed their map of walking. To change the limp, you might have to do one of two things:
- Convince them that their ankle is healed (they may be limping to protect the ankle because six months later they still have pain and don’t believe that it has fully healed) and/or
- Teach them how to walk again with a lot of sensory awareness (Read Todd Hargrove on using slow, purposeful movement to improve coordination: https://www.bettermovement.org/blog/2010/why-practice-slow-movement?rq=Slow movement. We do this all the time. We break down an activity into small chunks and get patients to do it regularly. This is remapping. Remapping isn’t new for us. However, consciously targeting the brain is new. Most of us have been doing this therapeutically in many of our interventions without even realizing it. Sometimes it just takes a small shift in our language but a huge shift in our clinical reasoning. Let’s unpack that.
We are really good as physiotherapists at breaking down an activity like walking, and retraining it. However, how do you break down sitting? Changing sitting posture and telling them to sit up straight usually doesn’t change things and the evidence behind postural correction is weak.
How do you break down generalized tension in the low back after an injury? How do you normalize the tone in the paraspinals, the abdominal wall (bracing) and the hip flexors which have learned to guard the area? You can stretch these muscles; this is what we have learned to do as PT’s. It may help because it changes the sensory and motor input into the sensori-motor cortex by re-training the neuromuscular system from the bottom up. But if the motor pattern in the brain has changed and defaulted to a pattern of protection, you may have to target the brain specifically to see any lasting changes in the tension of these muscles. (Moseley, G. Lorimer and Herta Flor. “Targeting Cortical Representations in the Treatment of Chronic Pain”. Neurorehabilitation and Neural Repair 26.6 (2012): 646-652. Web.) This is called a top-down approach.
Body mapping exercises such as Feldenkrais exercises (spend some time reading Bettermovement.org- a great blog on Feldenkrais exercises and mapping), Eric Franklin exercises (The franklinmethod.com – search You Tube for practitioner-driven video clips), and Tai Chi/Qi gong (read The Harvard Medical School Guide to Tai Chi by Peter Wayne, PhD) can be really helpful in finding exercises that target the cortical structures (top-down). It starts with pain education. Pain education targets the cortical structures to produce a change in how the brain perceives threats and processes inputs from the periphery. (Watch a great You Tube Educational video, “Understanding the Complexity of Pain”.
The resources that you have received from PHS are a remix of all of these techniques. What all of these exercises have in common are slow, repetitive movements that are very sensory-based, pain-free and novel. Targeting the brain teaches it not to default to the protective movement patterns- ie limping, tight muscles etc. that it has learned.
We now know in humans (not just monkey studies) that perceptually relevant changes occur in the sensory-motor maps within 24 hours of changing how a body part is used. (see: Kolasinski, James et al. “Perceptually Relevant Remapping of Human Somatotopy in 24 Hours”. eLife 5 (2016): n. pag. Web). Targeting the brain may logically produce quicker and more sustainable changes if that is where the origin of sensori-motor amnesia begins. Muscles may become weak and dis-coordinated, and movement patterns may become painful; however, the changes in the sensori-motor maps (which happen immediately after an injury) may be to blame. The Fre-BAQ gives us some insight into this. So does their progression into chronicity. Mapping issues may not explain the whole picture. Chronicity may also be explained by fear, catastrophization, depression, anxiety, stress and a negative belief system that they can be well. Therefore, unless you measure what is going on with every individual patient, you may not effectively and efficiently uncover the “driver” of the problem.
Every patient is a study sample of N=1. No two patients are identical. Mechanical pain occurs in a predictable pattern, and should be uncovered and treated easily. This is PT as we know it. You may also have a patient that has mechanical underpinnings; you address that, but then you can’t resolve them. There is a cortical component to their picture which also needs to be addressed. You may also have patients who are driven by top-down mechanisms predominantly. Tissues are healed, there are no identifiable mechanical patterns, and fear/catastrophization, allodynia, hypersensitivity, and diffuse pain are dominant (remember, if you don’t assess these factors you can’t treat them). These are also patients who usually have had multiple failed treatments, and treatment has become a nocebo for them. Don’t feed the nocebo. Don’t start mechanically with these patients because you will reinforce negative expectations associated with treatment and you will compromise your strong therapeutic alliance (it is harder to go backwards and start again then to move forwards).
Neuroscience research has shown that our brains are able to rewire themselves, and repetition is one of the key ways of doing that. Practicing re-mapping exercises can actually change your brain. Repeating small batches of novel, pain-free movement is a form of exercise, which allows your brain to develop new connections. It makes it more likely that you’ll actually be able to think and move differently, both now and in the future. To help with rewiring your brain, get plenty of sleep and exercise regularly. Practice relaxed and intentional movement 5-6x/day; this will make these new patterns the default mode your body will use rather than the pain/protective mode that it has become accustomed to.
Remapping exercises aren’t just something for the “difficult” patient. The more you use these exercises in your therapeutic interventions, the more they will become the default pattern of your exercise prescriptions. They are simple, work extremely well and are enjoyable for patients to do. They are effective because they target the brain, the master organ of all that we do. But, they also don’t replace a good physical exam to evaluate the bottom-up contributors to your patient’s presentation.
It starts with a really good, thorough physical exam, a great history-taking session and a thorough vetting of their psychosocial factors. Doing all of these things leads to confidence in your therapeutic alliance when prescribing the best exercises and approach. I suspect that most of us struggle because we are trying to take a short-cut through this process. If we do really great work up front, the rest becomes easy (or at least, easier). If you just try to prescribe a body-mapping exercise without laying the groundwork for it, it will seem forced and unconvincing. It has to be prescribed within the context of a biopsychosocial approach. Start again with a patient if you are stuck. You missed something along the way if they are giving you a blank stare and not understanding what you are asking them to do and why. Confidence in you and your treatment plan is probably the biggest predictor of success.
Change is difficult but worth it. The opioid crisis (http://www.cbc.ca/news/canada/british-columbia/fentanyl-crisis-pain-education-ubc-1.3959353), the cost of chronic low back pain, and our patient’s individual stories demands that we change.