I have mild shoulder impingement in my left shoulder which is almost unnoticeable when I am not at rest. As soon as I rest or sleep I get some discomfort. I think what is happening is when I am sleeping my shoulder tightens up & pulls my shoulder into the impingement zone. My right arm is fine but my left arm lacks horizontal abduction which I think maybe causing the problem. I also think I may have tight pecs which are contributing.

What kind of stretches could I do, if any, to give me back the range of motion in my left shoulder?

Theses are some pics of what I mean.

Front bicep pose: https://imgur.com/c0eEgUl 11
Right side: https://imgur.com/mFJXfFS 3
Left: https://imgur.com/2K8HXLu

As you can see from the bicep pose I cannot get my left shoulder (right on the pic) into the same position as the right. This is also noticable from the side views.

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