Hi My 14 Yr Old Son Was Playing Hockey And

Hi my 14 yr old son was playing hockey and he received a hit on his left shoulder. He is complaint of pain by his collar bone and on his back directly behind it. He can make a clicking grind noise just below his collar bone on the left side. If you put your hand on it you can feel it grind and pop. I brought him to the hospital the day he got hit, they took X-ray of his back and said that they did not see anything wrong. It has been 8 days now and it not getting better. Thanks for your help