Arm anatomy, shoulder to hand
The arm, or upper limb, runs from the shoulder to the fingertips and has 32 bones on each side. The clavicle and scapula attach it to the trunk, the humerus forms the upper arm, the radius and ulna form the forearm, and the hand has eight carpal bones, five metacarpals and fourteen phalanges. The shoulder, elbow and wrist are its main joints.
Frequently asked questions
How many bones are in the arm?
Each arm has 32 bones: the clavicle, scapula, humerus, radius and ulna, plus the 27 bones of the hand. The two arms together have 64.
How do the two forearm bones differ?
The radius is on the thumb side and the ulna on the little-finger side. The radius turns around the ulna to rotate the palm, while the ulna forms the hinge of the elbow with the humerus.
Which joint of the arm moves the most?
The shoulder joint. The socket of the scapula is shallow and the head of the humerus is large, so it moves in many directions and has the widest range of any joint in the body.
Parts in the arm
Bones of the arm
- Clavicle
- Scapula
- Humerus
- Radius
- Ulna
- Scaphoid
- Capitate
- First metacarpal bone
- Proximal phalanx of index finger
Joints of the arm
- Shoulder joint
- Acromioclavicular joint
- Elbow joint
- Radioulnar joints
- Wrist joint
- Thumb carpometacarpal joint
Bone counts
Compare
Other regions
Read more
- The human skeleton in 3D
- BAHI BODY 3D human body
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- Blog
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Once the 3D model loads you can turn it and select each part.