Recognition of the fact that injury or disease of joints is apt to be followed by atrophy of adjacent muscles, especially of the extensors above the joint, is said to date from the time of Hippocrates, but until the early part of the nineteenth century there was no serious attempt to explain why this atrophy occurred.
John Hunter spoke of it as being due to "sympathy," Whatever that may have meant. In 1860, Brown-Séquard advanced the idea that atrophy following joint disease was due to reflex irritation acting through the vasomotor system. Sabourin, in 1873, attributed it to direct extension of inflammation from the diseased joint, while Vulpain was the first to suggest that it was due to reflex influences exerted on the trophic nerve centers in the spinal cord, which opinion was later supported by in Charcot.Charcot. Valtat and Dide>in 1877' stucliod the change's in the muscles following arthritis
ALLEN CL. ARTHRITIC MUSCULAR ATROPHY. JAMA. 1911;LVII(26):2053-2055. doi:10.1001/jama.1911.04260120243008