Muscles Of The Shoulder Girdle Cont.

Question 1

Deltoid (anterior, posterior, middle)

Answer 1

Origin: clavicle and scapula
Insertion: deltoid tuberosity of humerus
Action: abduction at shoulder (whole muscle)
Innervation: axillary nerve

Question 2

Pectoralis Major

Answer 2

Origin: ribs 2-6, body of sternum
Insertion: greater tubercle of humerus
Action: flexion, abduction and medial rotation at shoulder
Innervation: pectoral nerves

Question 3

Supraspinatus (above spine of scapula)

Answer 3

Origin: supraspinatus fossa of scapula
Insertion: greater tubercle of humerus
Action: abduction at the shoulder
Innervation: suprascapular nerve

Question 4

Infraspinatus (below spine of scapula)

Answer 4

Origin: infraspinatus fossa of scapula
Insertion: greater tubercle of humerus
Action: lateral rotation at shoulder
Innervation: suprascapular nerve

Question 5

Teres Minor

Answer 5

Origin: lateral border of scapula
Insertion: greater tubercle of humerus
Action: lateral rotation at shoulder
Innervation: axillary nerve

Question 6

Teres major- not part of the rotator cuff

Answer 6

Origin: inferior angle of scapula
Insertion: intertubercular groove of humerus
Action: extension, adduction, and medial rotation of shoulder
Innervation: lower subscapular nerve