Over the past few days I seemed to have developed some kind of shoulder injury. I don't want to go into details but I'm now getting pain on my left shoulder when doing flat bench. I just read about joint force and that it can have instant pain relief effects. Wondering how long one bottle will last?. I just purchased two of them just in case. Should I only use it on an as needed basis?. Ok I'll tell you more about the shoulder "injury". I'm not sure what is going on but I was gaining strength on my bench press and kept adding weight each week. On Tuesday my left shoulder felt "off" and I was getting a few popping noises. Wednesday I went to the gym with the intention of doing some chest and shoulders. Anyway I got there and warmed up pretty good. I felt a bit of pain when I was warming up. Put on my working weight and I could barely do 2 reps without pain in my left shoulder. Now today it is difficult to even lift the lightest things around the house with my left arm. I've been trying to avoid the use of my left side. Never had an injury this debilitating. I'm old though so I guess it is inevitable that my shoulder/shoulders will give out. Hopefully I can find some alternate exercises that I can do. Either that or I just keep pushing through it. I just hate to have to give up benching even if it is only till/if my shoulder heals.