I tried a quad shot for the first time a couple of days ago. I used spotinjection guide for a reference point. About 1/4" in it felt like I hit something and it was quite painful. I angled the needle and seemed to "miss" the bad spot. Any ideas what I hit. It felt simialr to when a firend injected into my shoulder and went in a little too deep. I want to try another, but I was wondering what you guys think.