So I have been experiencing a pain in my shoulder and upper arm when I play. It starts off as a fatigued feeling almost as if I have been lifting weights but if I continue to play it progresses until it becomes quite painful. If I stop then the pain subsides until I start playing again but if I play through the pain for a while my shoulder might ache for a few hours after (I only did this once, I know it's terrible for me to do this). This mainly happens if I play on the G string for a while (Dragonetti, vomit drills or high octave scales etc...). I thought for a while that it was linked to flexibility but I have been stretching before I play for a few months now and it doesn't seem to be helping. I am about to take a trip to the doctor to have him take a look at it but I am wondering if any of you have had this problem or have any ideas as to what it could be. Thanks.