Upper limb

Common Tendon of Biceps Brachii

Tendo musculi bicipitis brachii

Origin

Long head: supraglenoid tubercle of the scapula; short head: coracoid process of the scapula

Insertion

Radial tuberosity, with an extension of the bicipital aponeurosis (lacertus fibrosus) into the fascia of the forearm

Function

Powerful flexion and supination of the elbow (biceps is the strongest supinator, especially in flexion)

Innervation

Musculocutaneous nerve

Movement & chain

This distal tendon channels the force of both muscle bellies (long and short head) onto the pivot point of the radial tuberosity; the supinating action is greatest at 90 degrees of elbow flexion, classically tested with a screwdriver motion.

Palpation

The tendon is readily palpable in the elbow crease, medial to brachioradialis, during flexion against resistance in supination.

Clinical

Ruptures of the distal biceps tendon usually occur under eccentric load (e.g. lifting with sudden resistance) and produce a visible 'Popeye' deformity of the upper arm.

Segmental innervation

Musculocutaneous nerve, C5-C6.

In clinical practice

On suspicion of a distal biceps tendon rupture, the 'hook test' is performed here: hooking a finger behind the intact tendon confirms the diagnosis, while its absence indicates a (partial) rupture.

Region in the model

Upper limb