arms serve as our primary connection to people and objects, through our reach and our ability to grasp things: through defensive postures, arms can also prevent connection that might cause us harm. These roles are reflected symbolically both in verbal figurations and in the non-verbal communication that is known as body language.

The position of the arms is very important in body language. Arms folded across the chest, in Western cultures, suggest anger, hostility, or defensiveness. Loose-swinging arms suggest ease or confidence; arms clasped behind the back imply gravity or seriousness; arms clasped before the body suggest eagerness. Arms raised above the head convey either submission (especially with palms open and facing the other person) or victory and militancy (especially in conjunction with a fisted hand). In each case the position of the arms relative to the body imitates the emotion conveyed through being open or closed.

Relationships between Western people are frequently expressed through the physical connection of arms. Formal relations usually require handshakes, while more familiar relations might permit forearm clasps, shoulder clasps, or even hugs. While different cultures have different standards of personal space, most of them fall within the length of an adult arm. To ‘hold someone at arm's length’, therefore, is to enforce a somewhat unnatural distance.

Arms have entered the language as symbolic of closeness, connection, or safety. To be ‘arm-in-arm’, actually or figuratively, is to be in close communication. To ‘offer an arm’ and ‘with open arms’ symbolically suggest vulnerability, and so figuratively suggest trust, openness, and willingness. Similarly, the phrases ‘within arm's reach’ and ‘the long arm of the law’ both highlight the vulnerability of closeness, especially an inescapable closeness. Finally, to designate someone as one's ‘right arm’ marks him or her as essential to one's own work, as both connected to oneself and a means of connection elsewhere.

The arms are an important means of defence of our vulnerable points, including the head, chest, and abdomen, as well as of antagonistic connections to others. As such, arms have become our primary metaphor for weaponry, which originally acted to extend the natural capabilities of the arms: reach (spears or swords), throwing or mobility (slings), and blockage (shields). While modern weaponry has far outstripped even the suggested or symbolic capabilities of arms, the connection lives on in our military vocabulary: a soldier was originally a ‘man-at-arms’; guns of all sorts are referred to as ‘firearms’; to surrender is to ‘lay down arms’; to fight or threaten is to be ‘up in arms’. The heraldic coat of arms was originally a cover of insignia on shields for fully armoured knights; as nobility became hereditary, the coat of arms became an identification of a family.

In anatomical terms, the arm is built around three bones; — the humerus in the upper arm, and the radius and the ulna in the forearm. The humerus articulates with the scapula (shoulder blade) at the shoulder, and with the radius and the ulna at the elbow. The arm is linked to the trunk by the shoulder girdle, formed by the scapula and the clavicle (collar bone). The most familiar and obvious muscles of the upper arm, particularly when developed by strength training, are the deltoid, biceps, and triceps. The deltoid muscle fleshes out the curve of the shoulder, and acts to raise the arm, by being attached to the shoulder girdle above and to the humerus below. The biceps muscle on the front and the triceps on the back span the upper arm from the shoulder girdle to below the elbow, so they can flex and extend the elbow respectively. Other, deeper muscles assist elbow flexion. In the forearm, the muscles are mainly those used for movements at the wrist and at the joints in the hand; grasping, and all the finer finger and thumb movements, are achieved by contraction of forearm muscles via the long tendons that span both the front and back of the wrist, assisted by the small muscles within the hand itself. The nerves which serve sensory and motor function in the arm come from the brachial plexus in the neck, derived through this mainly from the lower cervical segments of the spinal cord. The main arterial channel carrying blood to the arm changes its name from subclavian, as it runs behind the collar bone, to axillary in the armpit, and to brachial in the arm itself, dividing at the elbow into the radial artery (familiar for taking the pulse at the wrist) and the ulna artery, which both finally supply branches to the hand.

Julie Vedder, and Sheila Jennett

ARMS (ɑːmz) Action for Research into Multiple Sclerosis
• Associate of the Royal Society of Miniature Painters