I have been having pain in my left shoulder whenever I do wall presses (spider climbs to some). I don't really know if it is a strained muscle or something, but it only takes two or three presses for the pain to shoot up. I haven't fallen on it, or stretched it too hard, and I haven't always had the pain, and I trained wall presses for a week or two before it started to hurt.
It is either in my deltoid or coracobrachialis... I think the second, based on which stretch helps to alleviate the pain.
It doesn't really impact my training much because wall presses are the only thing that make it hurt, but I do want to continue training them again ASAP.