I am young.. 24... I think that my problem may be related to overuse from weightlifting and swimming over the years... anyways I used to never have problems with swimming, only certain weightlifting exercises would aggravate it, but recently it has been feeling funny.
Whenever my left shoulder feels really stretched out in my armpit area. If I try and stretch my chest I dont get a whole lot out of the stretch as I feel my armpit stretching out more. The whole area does not feel nearly as stable as the right side. When I do the catch I feel like I could take a much harder stroke if it was not for the weakness of that area. Also, I tend to dip my left arm into the water in a very awkward motion during freestyle... I think I am shying away from getting my elbow high and then pushing it far out in front of me. Lots of popping and clicking going on.
I have been doing plenty of RC exercises and other exercises to strengthen the area around my shoulder blade on that side... and I do feel them working but when I go to swim again it sets me back.
I should also mention that there is usually no pain and probably no inflamation either.