Desensitization. Honestly, not a very fun approach to an orthopedic manual physical therapist! I do sort of gripe to myself when I know I need to do this. Results usually are not quick (which we all like!) and the underlying “problem” is quite complicated and not well understood.
We typically use desensitization to specific areas of the body, particularly the distal limbs, in order to create a more normal response from a sympathetic nervous system principle to different grades of touch. This helps in decreasing the hypersensitivity, or more specifically allodynia, of pain when a light pressure/touch or brushing of the skin occurs. I know many of you know more about the molecular and cellular level of allodynia, but I am going to explain a more pragmatic approach to clinical practice.
A Case Example:
I recently had an older lady who had her radial artery harvested for coronary artery revascularization. Not to get into awful detail, she came to me many months later basically for strengthening of the wrist/hand and desensitization. As a fairly common side effect of this procedure, the patient presented with distal/lateral radial antebrachium and dorsal thenar parasthesias from an insult to the superficial radial nerve. It was bad enough that the patient could not sleep, could not wear sleeves/gloves and literally jumped if lightly touched, aka allodynia. Very disrupting to quality of life as you can expect and was even going to go get the nerve ‘burned’ until she asked surgeon to come to therapy.
Desensitization obviously came to mind but even the most soft material, such as silk, was a painful stimulus. I wanted more as I was not satisfied. I tend to treat by the approach of,
“if you can satisfy yourself, you can satisfy your patients”
I opted to perform a more reflex inhibition approach through muscle energy techniques to the antagonist aspect of her thumb. Meaning, I performed thumb MCP and thumb IP flexion low level contractions with a hold (see below).
and BAM! Immediate results with no pain during light touch to the same region. I was then able to prescribe this as a self-care approach at home (using her other hand) and then a more effective desensitization routine. She was satisfied and I was satisfied. I can’t remember how many visits it took, but I can assure you she recovered much quicker this way.
I have since used this technique on patients s/p ulnar nerve transposition (using other muscle groups of course) with again good results. I encourage you to try! Let me know what you think, especially those out there who are more well-versed and trained in neurodynamics.