1.
Deltoid:
Answer: Origin: 1. Lateral 1/3 of clavicle (anterior fibers)
2. Acromion (lateral fibers)
3. Spine of scapula (posterior fibers)
Insertion: Deltoid tuberosity of humerus
Functions: (7) 1. Flexion of arm @ gleno-humeral joint (anterior fibers)
2. Extension of arm @ shoulder joint (posterior fibers)
3. Abduction of arm @ shoulder joint (entire muscle)
4. Medial rotation of arm @ shoulder joint (anterior fibers)
5. Lateral rotation of arm @ shoulder joint (posterior fibers)
6. Horizontal Adduction of arm @ shoulder joint (anterior fibers)
7. Horizontal Abduction of arm @ shoulder joint (posterior fibers)
Nerve: Axillary nerve (C5, 6)