Upper limb
Biceps Brachii, Long Head
Musculus biceps brachii (caput longum)
- Origin
- Supraglenoid tubercle of the scapula (intra-articular, via the labrum)
- Insertion
- Radial tuberosity and, via the bicipital aponeurosis, into the fascia of the forearm
- Function
- Flexes the elbow, supinates the forearm; also acts as a weak stabilizer of the humeral head and shoulder flexor
- Innervation
- Musculocutaneous nerve, C5–C6
- Movement & chain
- More effective as a supinator than as a flexor when the forearm is already supinated (classic screwdriver movement); brachialis largely takes over the flexion role during pronation.
- Palpation
- Palpable as the more lateral muscle belly on the anterior upper arm; the tendon itself lies intra-articularly and is not directly palpable.
- Clinical
- The tendon of the long head is a frequent site of tendinopathy and (proximal) rupture, often accompanied by a 'Popeye deformity' of the muscle belly after complete rupture.
- Segmental innervation
- Musculocutaneous nerve, C5–C6.
- In clinical practice
- The 'Popeye deformity' of the muscle belly after a proximal tendon rupture is a simple visual finding on physical examination of the upper arm.
- Region in the model
- Upper limb