Shoulder Tendonitis
Shoulder bursitis and tendinitis are common causes of shoulder pain and stiffness. They indicate swelling (inflammation) of a particular area within the shoulder joint.

The shoulder joint is kept stable by a group of muscles called the rotator cuff as well as the bicipital tendon (the tendon that keeps the upper arm bone within the shoulder socket). When the rotator cuff tendon or the bicipital tendon becomes inflamed and irritated it is called rotator cuff tendinitis or bicipital tendinitis.

An area called the subacromial bursa lies in the space between the shoulder tendons. The bursa is what protects these tendons. Subacromial bursitis occurs when the bursa becomes inflamed.

Both conditions (shoulder bursitis and tendinitis) can cause pain and stiffness around the shoulder and may exist together.