Upper limb
Deltoid, clavicular part (anterior fibers)
Musculus deltoideus (pars clavicularis)
- Origin
- Lateral third of the clavicle
- Insertion
- Deltoid tuberosity of the humerus
- Function
- Flexion (anteflexion) and internal rotation of the shoulder
- Innervation
- Axillary nerve (C5–C6)
- Movement & chain
- Anteflexes and internally rotates the arm; works together with pectoralis major (clavicular head) and coracobrachialis in this movement.
- Palpation
- Felt at the front of the shoulder during resisted anteflexion, distinguished from the acromial part by raising the arm forward rather than purely sideways.
- Clinical
- Injury to the axillary nerve (in shoulder dislocation or a fracture of the surgical neck of the humerus) causes loss of strength in all three parts and a numb area over the lateral shoulder.
- Segmental innervation
- Axillary nerve, C5–C6.
- 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