I am going on my 4th year in MBI, and I have a simular injury. I have been told that it is not from my horn but because of may years sitting hunched over my computer at work. From slouching over my keyboard my shoulder blades are no longer straight up and down, but tilted now. Extended periods of having my arm raised pinches the nerves, causing lose of strength and sometimes numbness in my hand. The good thing is it is my left hand that goes numb so I can still press the buttons.