Arm muscles

Anterior view of the thorax and upper limb showing the muscles that act on the anterior arm (biceps brachii, coracobrachialis and brachialis)

The arm muscles originate from different locations of the scapula to insert on the humerus and carry out their functions via the glenohumeral joint.

The arm muscles are organized into two compartments:

  • Anterior (flexor) compartment: biceps brachii, brachialis and coracobrachialis muscles. The muscles of the anterior compartment primarily adduct the arm in the shoulder joint and perform flexion of the forearm in the elbow joint. They also aid with flexion of the shoulder joint and supinate the forearm.
  • Posterior (extensor) compartment: triceps brachii and anconeus muscles. These muscles primarily extend the forearm in the elbow joint but also perform weak arm extension and adduction.

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