Muscles / Shoulders
Deltoid
- Shoulders
- Shoulder & scapula
- Superficial layer
Anatomy
- Origin
- Lateral third of the clavicle, acromion and spine of the scapula
- Insertion
- Deltoid tuberosity of the humerus
- Nerve
- Axillary nerve (C5-C6)
Actions
- Anterior part flexes and medially rotates the arm
- Middle part abducts the arm
- Posterior part extends and laterally rotates the arm
Parts
Notes
- Axillary nerve injury (surgical neck fracture, anterior dislocation) weakens abduction and reduces sensation over the "regimental badge" area.
References (4)
- Standring S, ed. Elsevier. Gray's Anatomy: The Anatomical Basis of Clinical Practice. 42nd ed.
- Dalley AF, Agur AMR. Wolters Kluwer. Moore's Clinically Oriented Anatomy. 9th ed.
- Neumann DA. Elsevier. Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation. 3rd ed.
- Betts JG, Young KA, Wise JA, et al. OpenStax (free, openly licensed textbook). Anatomy and Physiology 2e