What is the shoulder joint?

The the shoulder joint is called the glenohumeral joint. Gray's Anatomy (1918) describes it as a ball-and-socket synovial joint.

What it is

  • A ball-and-socket synovial joint.
  • Formed where the head of the humerus meets the shallow glenoid cavity of the scapula.
  • The most freely movable joint in the body.

Where it is

  • Between the upper arm and the trunk.
  • Reinforced by the tendons of the rotator cuff muscles.
  • Held in place mainly by muscles, since the socket is very shallow.

Source:

Last verified: 2026-07-18

  • Best Anatomy Answers is an educational reference about human anatomy. It is not medical advice — for any health concern, talk to a licensed medical professional.

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