Having a internal shoulder rotation or "rounded shoulders" can cause a series of different issues such as back pain, neck pain, headaches, or winged shoulder blades. If caught early the treatment and steps to help are very easily done and can be managed over time.
PECTORALIS MINOR STRETCH
Stand parallel to the wall with the target arm closest to the wall, Raise arm up vertically overhead and rest your hand on the wall. (first picture) *Note the space between you and the wall may need to be adjusted depending on your flexibility level
Without letting your body rotate slowly walk your hands back until a stretch is felt in the upper chest (second picture) *Note if fingers become numb or the stretch is too intense walk your fingers forward back to neutral.
This stretch will allow your pectoralis minor to lengthen and slowly put the shoulder blade back into a neutral resting position.