What is Double Crush?
The hypothesis for double crush was first expressed by Upton and McComas in a Lancet4 research article. They found electrophysiological evidence of cervical neural lesions associated with carpal tunnel and ulnar nerve entrapment syndromes. The researchers concluded that the neural lesions in the neck resulted in serial constraints of axoplasmic flow of nerve fibers. Thus, distal neural function could be impaired when single axons, having been compressed in one region, become especially susceptible to damage in another. Subsequent studies have reinforced the theory of Upton and McComas. A more recent article5 found that “acute and chronic compression of peripheral nerves can induce changes in intraneural microcirculation and nerve fiber structure, increase vascular permeability (with subsequent edema formation) and impair anterograde and retrograde axonal transport, all of which contribute to the clinical symptoms and deterioration of nerve function.”6 “The cell body response is probabl
