Double Crush Syndrome and why you need to know about this

upper extremity nerves

Sharing some thoughts from an interesting client seen in the clinic last week. What happens when the diagnosis doesn’t fit the clinical picture? For example, the client who presents with lateral elbow pain and is given the diagnosis of “tennis elbow” or technically “lateral epicondylitis”. This would seem plausible except for one reason: this particular client doesn’t play tennis and the pain is in the non-dominant hand. Now what?
One possible explanation is a phenomenon called “Double Crush Syndrome” that was first presented back in 1973 by Dr.’s Upton and McComis, MD who postulated that “damage to a nerve at one site along its course may sufficiently impair the overall functioning of the nerve cells so that they become more susceptible than would normally be the case to trauma at other sites”.
What exactly does this mean? A couple things to first keep in mind. Anytime you see “Syndrome” attached to anything (Fibromyalgia, Chronic Fatigue, and Myofascial Pain are all common Syndromes), understand that is medical code for “not really sure what’s going on”. We know “something’s up” just not sure what so let’s guess. Since the nerves that travel down and innervate the arm and hand start up at the neck, any “injury” to the nerves as they leave the neck can make them more likely to be irritated anywhere along the chain afterwards. What should be a sore wrist from computer work could turn in to Carpal Tunnel Syndrome (yes, there’s that word “syndrome” again) from a nerve irritation in the neck. This can also be said for lower extremity issues: plantar fasciitis, shin splints, Achilles tendonitis, etc. that could all have a lumbar spine or sacral “nerve” issue that could be clouding the clinical picture.
So what if you are like my client who’s having arm (or leg) pain that can’t be explained and you were questioning whether or not you have “Double Crush Syndrome”? Luckily, there are many tests that can be clinically done to determine if there is a “neuro-dynamic” component to your pain and if so, how it changes the course of treatment. Hope you enjoyed my ramblings, there is power in knowledge.
Cheers,
Ed