Glenohumeral joint in the context of "Humerus"

In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper arm between the elbow and the radiocarpal joint (wrist joint) is known as the forearm or "lower" arm, and the extremity beyond the wrist is the hand.

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. The Latin term brachium, which serves as a root word for naming many anatomical structures, may refer to either the upper arm as a whole or to the upper arm on its own.

An armlock in grappling is a single or double joint lock that hyperextends, hyperflexes or hyperrotates the elbow joint or shoulder joint. An armpit lock can be useful; it will immobilize an opponent and pin them on the ground. An armlock that hyperextends the elbow is known as an armbar, and it includes the traditional armbar (pressing the elbow against the thigh or hips), the shoulder triangle armbar (where a figure-four is locked with the legs), and the shotgun armbar (where the opponent's wrist is placed in the armpit, using the forearm as a fulcrum). An armlock that hyper-rotates the arm is known as an armcoil, and includes the Americana, kimura, and omaplata. Depending on the joint flexibility of a person, armcoils can either hyperrotate only the shoulder joint, only the elbow joint, or both the elbow joint and shoulder joint.

Obtaining an armlock requires effective use of full-body leverage in order to initiate and secure a lock on the targeted arm, while preventing the opponent from escaping the lock. Therefore, performing an armlock is less problematic on the ground, from positions such as the mount, side control, or guard. Armlocks are more difficult to perform when both combatants are standing up, though the stand-up variants are a focus in certain systems such as Chin Na.

The coracoid process (from Greek κόραξ, raven) is a small hook-like structure on the lateral edge of the superior anterior portion of the scapula (hence: coracoid, or "like a raven's beak"). Pointing laterally forward, it, together with the acromion, serves to stabilize the shoulder joint. It is palpable in the deltopectoral groove between the deltoid and pectoralis major muscles.