Hello- well I am not really sure what you are saying about the range of movement re left and right shoulders....

But I will tell you that I have the same lump on my left shoulder. For me I only discovered it about a month ago because normally my left shoulder drops back (behind) so it is normally not visible. But if I pull imy shoulder forward to where I think it should be (to make the 2 clavicles in line) and hold in my core, then this mound appears. I have looked in mirrors etc and the scalupa in back appears higher. The mound is attached to the scapula. I think this mound is the leavator scapulae but I am not a PT.

Do you talk a lot on a regular phone by cradling it in your shoulder?

I too would be interested in hearing what a PT has to say about this.

I am seeing a PT this week and if I have time I will ask here about it.

If I were you I would pursue this.

I might try posting a picture of mine in a few minutes- I'll see how complicated it is to do- ya forget it, my camera batteries just died.

But I wanted to add that I fell forward on a staright arm rollerblading a few years ago- maybe you sustained a similar injury at some point?