Bones and joints of the arm, forearm, and hand
The arm (upper appendage) is part of the appendicular skeleton. The appendicular skeleton includes the pelvis, upper, and lower limbs.
Bones of the Upper Appendage (Arm, forearm, and Hand)
- Shoulder girdle—consists of the scapula (shoulder blade) and clavicle (collar bone)
- Humerus—long bone of the upper arm
- Radius—long bone of the forearm; articulates with the humerus to form the elbow.
- Ulna—long bone of the forearm; also articulates with the humerus to form the elbow
- Carpals—8 small bones of the wrist — includes the scaphoid, lunate, capitate, trapezium, and others.
- Metacarpals—small bones of the hand
- Phalanges—14 bones of the fingers (3 in each finger) and thumb (2 in the thumb)
Joints of the Upper Appendage (Arm)
- Shoulder—Made up of the scapula and the humerus. It is a ball and socket joint which links the arm to the trunk. It is located away from the trunk so that the arm can move freely. The arm hangs vertically besides the trunk.
- Elbow joint—A hinged-type joint formed by the humerus, ulna, and radius – The elbow can bend from approximately 0 – 160°.
- Wrist joint- otherwise known as the radiocarpal joint. This joint links the carpal bones of the hand to the radius and ulna bones of the forearm.
- Finger joints- otherwise known as the metacarpophalangeal and interphalangeal joints. These are the joints created between the metacarpal bones and the phalanges (finger bones). Additionally, multiple joints exist between adjacent phalanges. These joints move the fingers toward the palm of the hand. This movement is called finger flexion.