By anatomical definitions, the bones, ligaments and skeletal muscles of the shoulder girdle, as well as the axilla between them, are considered parts of the upper limb, and thus also components of the arm.

This fact is very important clinically as a fracture of the shaft of the bone here can cause lesions or even transections in the nerve.

The deep artery of the arm travels through the lower triangular space with the radial nerve.

Therefore, fracture of the bone may not only lead to lesion of the radial nerve, but also haematoma of the internal structures of the arm.

The basilic vein travels on the medial side of the arm and terminates at the level of the seventh rib.

In Hindu, Buddhist and Egyptian iconography the symbol of the arm is used to illustrate the power of the sovereign.

In Hindu tradition gods are depicted with several arms which carry specific symbols of their powers.

In West Africa, the Bambara use forearm to symbolize the spirit, which is a link between God and man.

Symbolic gestures of raising both hands signal surrender, appeals for mercy, and justice.

However, in common, literary, and historical usage, arm refers to the entire upper limb from shoulder to wrist.

The ball and socket shoulder joint allows for movement of the arms in a wide circular plane, while the structure of the two forearm bones which can rotate around each other allows for additional range of motion at that level.