Shoulder Anatomy

The labrum deepens the socket of the shoulder joint, making it a stronger fit for the head of the humerus.

The shoulder joint has three bones: the shoulder blade (scapula), the collarbone (clavicle), and the upper arm bone (humerus). The head of the upper arm bone (humeral head) rests in a shallow socket in the shoulder blade called the glenoid. The head of the upper arm bone is usually much larger than the socket, and a soft fibrous tissue rim called the labrum surrounds the socket to help stabilize the joint. The rim deepens the socket by up to 50% so that the head of the upper arm bone fits better. In addition, it serves as an attachment site for several ligaments.

What causes a shoulder to tear?

Injuries to the tissue rim surrounding the shoulder socket can occur from acute trauma or repetitive shoulder motion. Examples of traumatic injury include:

  • Falling on an outstretched arm
  • A direct blow to the shoulder
  • A sudden pull, such as when trying to lift a heavy object
  • A violent overhead reach, such as when trying to stop a fall or slide

Throwing athletes or weightlifters can experience glenoid labrum tears as a result of repetitive shoulder motion.

What are the symptoms of a torn shoulder?

The symptoms of a tear in the shoulder socket rim are very similar to those of other shoulder injuries. Symptoms include

  • A sense of instability in the shoulder
  • Shoulder dislocations
  • Pain, usually with overhead activities
  • Catching, locking, popping, or grinding
  • Occasional night pain or pain with daily activities
  • Decreased range of motion
  • Loss of strength

Departments and Programs Who Treat This Condition

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We provide comprehensive orthopedic care for acute and chronic conditions to help you get back to the activities you love.
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Shoulder injuries and shoulder pain are common and can significantly limit daily activities and impact function. At BMC, we provide both medical and surgical treatment for shoulde…
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BMC’s sports medicine experts have extensive expertise in both knee and shoulder care. We’ll work diligently to get you back to all the activities that you love, starting with con…