Which bone forms the socket for the shoulder joint, enabling arm movement?

Which bone forms the socket for the shoulder joint, enabling arm movement?

• A. Clavicle
• B. Radius
• C. Phalanges
• D. Scapula

Answer: (D)

The shoulder’s ability to move so freely comes from a ball-and-socket setup where the head of the humerus sits in a shallow cup called the glenoid cavity, which is part of the scapula. So the bone that forms the socket is the scapula. This socket allows a wide range of arm motions, aided by the surrounding ligaments, the glenoid rim (labrum), and the rotator cuff muscles. The clavicle helps position the shoulder and transmit forces but does not form the socket. The radius is a forearm bone, and the phalanges are finger bones, so neither forms the shoulder socket.

The shoulder’s ability to move so freely comes from a ball-and-socket setup where the head of the humerus sits in a shallow cup called the glenoid cavity, which is part of the scapula. So the bone that forms the socket is the scapula. This socket allows a wide range of arm motions, aided by the surrounding ligaments, the glenoid rim (labrum), and the rotator cuff muscles. The clavicle helps position the shoulder and transmit forces but does not form the socket. The radius is a forearm bone, and the phalanges are finger bones, so neither forms the shoulder socket.