Deep in the shoulder are a group of tendons and muscles called the rotator cuff. They help stabilize the upper arm bone in the shoulder joint and rotate the arm. The bicep's tendon is located in front of the shoulder. When the arm is raised repeatedly over the head, the tendons rub against the underside of the shoulder bone and become irritated. The tendons swell, leaving even less space between tendons and bone. This creates more irritation, like a rope being drawn again and again across a craggy rock. This irritation is tendonitis.


  • Continuous ache
  • Spasms
  • Limited range of motion
  • Stiffness


  • Stabilize the shoulder by using a sling or brace
  • Anti-inflammatory medication
  • Corticosteroid injections
  • Compression (ice pack)
  • Surgery