Biceps Exercises

The biceps brachii is the most visible muscle on the front of the arm. Despite its notoriety, it is not the largest muscle in the arm (that distinction belongs to the triceps). The biceps is a bipennate muscle composed of two heads: the long head and the short head. Both insert onto the radial tuberosity but originate from different points on the scapula.

The long head originates from the supraglenoid tubercle of the scapula and passes through the bicipital groove of the humerus. It is responsible for the peak of the bicep when the muscle is contracted and contributes to elbow flexion. The short head originates from the coracoid process and contributes more to muscle width. A narrower grip in curls emphasizes the long head, while a wider or outward-angled grip emphasizes the short head.

The functions of the biceps include: elbow flexion (the primary function), forearm supination (rotating the palm upward), and a minor contribution to shoulder flexion. The supination function is important: the biceps is a powerful supinator, meaning curls performed with the palm facing up (supination) stress the biceps far more intensely than neutral grip curls (hammer curls).

The brachialis is a muscle underneath the biceps that contributes significantly to elbow flexion. It is a purer flexor (having no supination function) and is trained effectively with hammer curls and pronated grip curls. Developing the brachialis literally pushes the biceps upward, increasing the visual peak.

The brachioradialis is a forearm muscle that participates in elbow flexion, particularly active with a neutral grip (hammer curl) and when the forearm is semi-pronated. A complete arm training program must consider all three of these muscles for balanced and proportional development.