When it comes to shoulder mechanics one of the first places to check is the thoracic spine. The t-spine is intimately related with the shoulder. Most have horrible t-spine extension & rotation range of motion which is critical for stabilizing the scapula to the thorax. I cannot tell you how many people think that doing only rotator cuff exercises will cure every shoulder problem known to man. Think about all the hours total that you sit, watch TV, play video games, & eat. Does your work consists of sitting a lot? Right now, simply hunch over and try to reach your arm straight over head. Notice the range of motion you have with letting yourself sit up tall. Now, simply sit in a good tall posture and raise your arm overhead. Most likely, unless you’re a mutant, you will easily have more range of motion simply because you put your thoracic spine in a better position. In fact, sometimes you can do only t-spine mobility drills along with scapular strengthening exercises to improve ROM and keep the shoulder happy. David Lasnier had a great post on this earlier in the week. If you have a shoulder issue with things like bench pressing, I highly advise upping the scapular strengthening exercises (rows & retraction type exercises) and hammering away on your t-spine. You can even use these as part of your warm-up. Here are some of the ones we use with our athletes.
Quadruped Extension-Rotation with Internal Rotation
Bent Over T-Spine Rotation
T-Extension of Foam Roller: do not extend from lumbar spine
There are many more that you can do that I will incorporate into another post, but these are some that most people and athletes can benefit from right from the start.