It looks (& feels) like I have a rotator cuff injury. I fell over some packing paper (only a klutz like me would trip over paper) back in December when the movers were packing our stuff. I
a) landed on my left knee,
b) inverted my right ankle, and
c) used my left outstretched arm to catch my fall so that I wouldn't land on my face.
The knee & ankle have since recovered. But I find myself wincing each time I take off my shirt or use my left arm to reach for something overhead - quite classical of rotator cuff injuries. Passive abduction is fine (I used my son to test this :)) but active abduction hurts. Even lying on my left side is not comfortable.
Am going to take Nsaid's for a few days (something I usually try to avoid) as 3 months is a bit long for this to go on. I took Celebrex a couple of times, but not at a stretch. Also tried traditional Chinese massage by a trained Chinese masseur (I'm in China after all!). The pressure he used felt good but the manipulation was not pleasant at all (although after the first session, the pain did lessen for a day), and I am not comfortable with all the joint stretching that he does (ouch!).
I've been using some light weights to try to strengthen the shoulder muscles, & doing some stretching to try to maintain/improve range of motion. I hope I don't need to go for physiotherapy. Being in a foreign country & looking for good healthcare is a bit daunting. On the other hand, I don't want to end up with Frozen Shoulder either.