Muscles of the shoulder

Question 0

rhomboid major

Answer 0

Origin: s-pros T2-T5
Insertion: med border of scap from root of the spine to inferior angle
Innervation: dorsal scapular nerve (c4, C5)
Action: retracts scap, inf rotation of glenoid

Question 1

trapeiuz

Answer 1

Origin: EOP, medial 1/3 of SUP nuchal line, nuchal ligament, s-pros of C7-T12
Insertion: lat 1/3 of clavicle, acromion, scapular spine
Innervation: motor (spinal) accessory nerve (CN XI); sensory - C3-C4 (pain, pressure)
Action: desc: elevates scapula; ascend: depresses scap, all - retracts scap, both asc and desc sup rotation of glenoid

C3, C4 shrug some more!!

Question 2

rhomboid minor

Answer 2

Origin: s-pros C7-T1, nuchal lig
Insertion: med border of scap AT the root of the scap spine
Innervation: dorsal scapular nerve (c4, C5)
Action: retracts scap, inf rotation of glenoid

Question 3

levator scapulae

Answer 3

Origin: posterior tubercles of transverse processes of C1-C4
Insertion: med. border of scapula SUP to root of scapular spine
Innervation: C3, C4, and dorsal scapular nerve (C5)
Action: elevates scapula, inferior rotation of glenoid

Question 4

supraspinatus

Answer 4

Origin: supraspinous fossa
Insertion: superior facet of greater tubercle
Innervation: suprascapular nerve (C4, C5, C6)
Action: initiates and assists the deltoid in abduction (1st 15 degrees) holds humeral head in glenoid

Question 5

infraspinatus

Answer 5

Origin: infraspinous fossa
Insertion: middle facet of greater tubercle
Innervation: suprascapular nerve, (C5 and C6)
Action: lateral rotation, holds humeral head in glenoid

Question 6

subscapularis

Answer 6

Origin: subscapular fossa
Insertion: lesser tubercle
Innervation: upper and lower subscapular nerves (C5, C6, C7)
Action: med and adduction rotation, holds humeral head in glenoid

Question 7

teres minor

Answer 7

Origin: middle part at lateral border of scapula
Insertion: inferior facet of greater tubercle
Innervation: axillary nerve C5, C6
Action: lateral rotation, holds humeral head in glenoid

Question 8

teres major

Answer 8

Origin: inf part of lateral border of the scapula and posterior surface of the inf angle of the scapula
Insertion: medial lip of intertubercular sulcus of humerus
Innervation: lower subscapular nerve (C5, C6)
Action: adducts and medially rotates shoulder joint

Question 9

deltoid

Answer 9

Origin: lateral 1/3 of clavicle; acromion and spine of scapula
Insertion: deltoid tuberosity of humerus
Innervation: axillary nerve (C5, C6)
Action:
anterior fibers (clavicular): flexes and medially rotates shoulder
middle fibers (acromial): abducts shoulder joint
posterior fibers (spinal): extends and laterally rotates shoulder joint

Question 10

latissimus dorsi

Answer 10

Origin: thoracolumbar fascia, iliac crest, inferior 3 or 4 ribs, s-pros of T6-T12
Insertion: floor of intertubercular sulcus
Innervation: thoracodorsal nerve (C6, C7, C8)
Action: adducts, medially rotates, and extend humerus

C6, 7, 8 Lats are Great!!