GTT

Ive a pain in my left shoulder, if i do any pressing movement where my elbows are pulled right back, like dumbell bench press, shoulder press, flies it hurts like hell, trained very light for a couple of weeks and it doesnt feel any better..however

I can do flat bench with a narrower grip without pain, i can do dumbell front raises with no pain whatsoever and i can do dumbell side raises with no pain except a slight twinge as i get to the very top of the movement, slightly above parallell with the ground.

What have i damaged?

I cant work out wether the pain is comming from my side delt or my front but it feels as though it extends partially down the tendon onto my arm.

I reiterate the pain occurs whenever my left shoulder is at full stretch.