If the pectoralis and latissimus are tight or overly developed, they can alter how the arm bone and/or scapula rests and moves. Again, they tend to dominate arm movements because of how we typically work with our arms and the muscles' sheer size. This makes it difficult for the rotator cuff muscles to guide the head of the humerus in the shoulder socket. When this happens, the rotator cuff internal rotators also become tight, reinforcing this problem. This is often the case in weight lifters whose training emphasizes bigger or stronger chest and back muscles while excluding scapular and rotator-cuff muscles.
Find out more about this book:Fixing You: Shoulder & Elbow Pain: Self-treatment for rotator cuff strain, shoulder impingement, tennis elbow, golfer's elbow, and other diagnoses.