Take care of your shoulders
The shoulder complex is a very sensitive area being injured because it lacks structural stability, contrary to what happens with other joints of the body.
Follow this analogy: the shoulder is like a tennis ball on a small plate and the hip is like a golf ball into a cup of coffee. Here it is easy to see that the shoulder is more mobile than the hip and less stability. It would only be possible to achieve something different positions, rotating the arm, make a service tennis, golf, etc.
Because there is this deficit in stability is very important prescribe exercises that represent a suitable challenge for the structures that stabilize the shoulder, in this case the muscles.
To the average person it is difficult to understand which are the most vulnerable positions for this complex, to know when it is appropriate to push and carry a little more weight for example, so there are physical exercise professionals who (a) help maintain shoulder integrity through a rigorous evaluation and prescription.
Do not make risky bets with your body, because often the consequences are for the rest of his life.
Continuation of good practice!