What is a ball and socket joint?

A ball and socket joint is a type of synovial joint, such as the hip and shoulder joints. In this type of joint, one bone has a smooth, ball-shaped head that fits into a cuplike socket on the other end. In the hip, the head of the femur has a hemispherical shape that fits in the cuplike socket of the acetabulum of the pelvis. This type of joint is one of the most moveable joints in the body.

This answer provided for NATA by the University of Tampa Athletic Training Education Program.

Dr. Jeanne Morrison, PhD
Family Practitioner

Your hip, shoulder and ankle are all examples of ball and socket joints. The ball and joint sockets contain a cup-like bone socket that holds a rounded ball-shaped bone. These ball and socket joint is held in place by a lining of cartlidge.


Dr. Mehmet Oz, MD
Cardiologist (Heart Specialist)

The hip is an example of a ball and socket joint, which means a rounded ball of bone at one end of the thighbone, or femur, moves inside a cup-like socket that is part of the pelvis.

A ball and socket joint is what it sounds like. Your shoulder joint and your hip joint are shaped like a ball. The other sides of those joints look like a cup and that's why it is called a ball and socket.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.