I had trouble with the left shoulder. I had severe pain like I had arthritis. I could not use my left hand while I was in the shower. I had a bad pain in my neck, I used to spend 14 hours at the computer. Practicing karate for 5 months and regained my shoulder and arm to normal. When I sit down I have no pain in the neck. Hand techniques Uchi Uke and Soto Uke helped me the most, these two techniques are afflicted me most in nerve. I have test for yellow belt next week