I was a competitive swimmer in high school and now swim recreationally and while working as a lifeguard. A few months ago I felt a painful pop in my shoulder while lifting a boat and I was diagnosed with impingement and instability. I did 8 weeks of PT and all was well. Recently I got back in the pool, to begin light workouts for lifeguarding I am now experiencing a painful pop during the pull of my stroke...this also seems to occur randomly when reaching for things. Any ideas as to what this may be?