Experimental: Embolization

Angiography will be performed to identify hyperemic neovasculature arising from one or more of branch shoulder arteries. After localizing the abnormal neovessels a microcatheter will be inserted coaxially and selectively placed in the targeted artery(ies). The abnormal vessels will be embolized with Lipiodol emulsion (Guerbet, Villepinte, France) The embolic agent will be used under an investigational device exemption from the FDA. The embolic will be injected in small volume increments until blood flow stagnates in the target artery(ies).~Angiography and embolization will be repeated until the hyperemia is markedly reduced as demonstrated on digital subtraction angiography.~Subjects will participate in structured physical therapy consisting of 3 months of eccentric strength training. This twelve-week program will consist of 4 PT sessions at week 0, week 4, week 8, and week 12.

Active_comparator: Physical Therapy

Subjects will participate in structured physical therapy consisting of 3 months of eccentric strength training. This twelve-week program will consist of 4 PT sessions at week 0, week 4, week 8, and week 12.