Bones of the Upper Limb
The bones of the upper limb can be divided into four main groups: the shoulder girdle, arm, forearm and hand. In contrast to the lower limb (which is involved in weight-bearing and locomotion), the main role of the upper limb is to control the position of the hand in space – enabling manipulation of objects in the environment.
The most proximal region is the shoulder girdle. It is comprised of two bones – the clavicle and scapula. The scapula is a triangular, flat bone, which serves as a site for attachment for numerous muscles. Anteriorly, the clavicle articulates with the sternum, thereby attaching the upper limb to the axial skeleton.
The humerus provides skeletal support for the arm. It articulates proximally with the scapula at the glenohumeral joint and distally with the bones of the forearm at the elbow joint.
The forearm bones consist of the ulna (medially) and the radius (laterally). The radius pivots around the ulna to produce movement at the proximal and distal radio-ulnar joints. The ulna plays a stabilising role in the forearm.
The bones of the hand include the carpals, metacarpals and phalanges. The carpals are eight bones, organised into two rows, located within the wrist area. They are articulate distally with five metacarpal bones (one for each digit). The phalanges are the bones of the digits – each finger has three phalanges, except for the thumb, which has two.
In this section, learn more about the anatomy of the bones of the upper limb – the clavicle, scapula, humerus, radius, ulna and hand bones.