One of the best shoulder rehab exercises I use with my clients are shoulder dislocations. I personally had a chronic shoulder injury several years ago, and even after going to my primary doctor and several sports rehab guys, oddly enough it was this exercise that completely eliminated all the pain I had. I've seen the same thing happen for several people now so this has become one of my favorite rehab exercises.
You need a long broomstick or something similar to do this stretch. Here's a video that shows you how to do it:
https://www.youtube.com/watch?v=33P5AI27eiU#t=17
Here are some important rules to keep in mind:
- Use the widest grip possible on the broomstick when you're starting out. The wider the grip, the easier the stretch. When I first started, I could only do this stretch with proper form while holding the broomstick with only two fingers on each side.
- Don't move as quickly as the guy in the video. Start out slowly and make sure you keep proper form. You want your elbows to be locked the entire time. Absolutely no cheating on this or it defeats the point of the stretch.
- Start off doing 20 reps per day, once a day.
- Whenever you're able to, narrow your grip on the broomstick a little bit. As you move your hands closer to each other and narrow your grip, the stretch becomes more effective and your range of motion with shoulders will improve dramatically.
Let me know if you have any questions about this. Shoulder injuries are awful to deal with and prevent you from doing a lot of the most effective exercises, so you want to get this sorted out ASAP. Then we can move on to your chin-up goals