Week 11 - Arm and shoulder muscles Flashcards
What are the actions of the trapezius?
- Scapular retraction
- Rotates scapula
- Elevates scapula
- Depresses scapula
What is the innervation of the trapezius muscle?
Accessory nerve (CN XI)
What is the origin of the trapezius?
- External occipital protuberance
- Ligamentum nuchae
- Spines of C7-T12
What is the insertion of the trapezius?
- Scapular spine and acromion
- Lateral 1/3 of clavicle
What are the actions of the latissimus dorsi?
- Adducts the arm
- Extends the arm
- Rotates arm medially
- Depresses scapula
What is the innervation of latissimus dorsi?
Thoracodorsal nerve (C6-C8)
What is the origin of the latissimus dorsi?
- Iliac crest
- Spinous process of T7-T12
- Ribs 9-12
What is the insertion of the latissimus dorsi
- Intertubercular sulcus of humerus
What is the action of the levator scapulae?
(Deep to trapezius)
- Elevates scapula
- Downward rotation of scapula
What is the innervation of the levator scapulae?
Dorsal scapular (C5)
What is the origin of the levator scapulae?
- Transverse process of C1-C4
What is the insertion of the levator scapulae?
- Superior angle of scapula
What is the action of the rhomboid major?
- Scapular retraction
What is the innervation of the rhomboid major?
Dorsal scapular (C5)
What is the origin of the rhomboid major?
- Spines of t2-t5
What is the insertion of the rhomboid major?
Medial boarder of scapula
What is the action of the rhomboid minor?
Scapular retraction?
What is the innervation of the rhomboid minor?
Dorsal scapular (C5)
What is the origin of the rhomboid major?
Spines of C7-t1
What is the insertion of the rhomboid minor?
Medial border of scapula
What are the actions of the anterior fibers of the deltoid?
- Flex the arm
- Medially rotates the arm
What are the actions of the middle fibers of the deltoid?
- Abduct the arm (agonist)
What are the actions of the posterior fibers of the deltoid?
- Extends the arm
- Laterally rotates the arm
What is the innervation of the deltoid?
Axillary (C5-C6)
What is the origin of the deltoid?
- Acromion process
- Lateral 1/3 of Clavicle Spine of scapula
What is the insertion of the deltoid?
- Deltoid tuberosity of the humerus
What are the actions of the teres major?
- Extends arm
- Medially rotates arm
- Adducts arm
What is the innervation of the teres major?
Lower subscapular nerve (C5-C6)
What is the origin of the teres major
Inferior angle of scapula