There is a small fluid-filled cushion at the top of the shoulder called the bursa which protects the rotator cuff muscles from rubbing on the bony acromion (found at the very edge of the shoulder). Bursitis is an inflammation of this cushion that results in pain and swelling, typically worsened with overhead activities. Shoulder bursitis can be caused by overuse of the arm such as in repetitive throwing, or from a trauma such as falling onto your hands.
Reducing inflammation is the key step in treating shoulder bursitis, which is why rest, ice and anti-inflammatory medication are commonly prescribed for this condition. What is less commonly addressed, is the reflexive, protective spasm found in the fascia surrounding veins, nerves and arteries, in addition to fascia found within muscles, ligaments and bone. Even the support tissues that anchor the heart and lungs to spinal vertebrae, ribs and sternum, can spasm and affect posture and mobility. These protective reflexes are caused by injury or trauma to the body and are found in multiple tissue systems.