Upper limb
Brachialis
Musculus brachialis
- Origin
- Distal half of the anterior surface of the humerus
- Insertion
- Coronoid process and ulnar tuberosity
- Function
- Primary flexor of the elbow
- Innervation
- Musculocutaneous nerve (partly also radial nerve)
- Movement & chain
- Flexes the elbow regardless of forearm position, unlike biceps brachii, which is most effective in supination. Under heavy flexion load, this is the most important muscle.
- Palpation
- Felt on either side of the biceps brachii tendon, just proximal to the elbow crease, during resisted flexion in pronation.
- Clinical
- Shortening contributes to flexion limitation after prolonged elbow immobilization. Myositis ossificans occurs here following elbow trauma.
- Segmental innervation
- Musculocutaneous nerve, C5–C6; the lateral part partly via the radial nerve (C7).
- In clinical practice
- Safe transfer techniques avoiding arm traction (prevents shoulder subluxation in stroke patients); monitor injection sites and offload scapular pressure.
- Region in the model
- Upper limb