Glenohumeral Joint Muscles/mechanics

Question 1

Muscles responsible for shoulder abduction?

Answer 1

Deltoid, supraspinatus, upper pec major

Question 2

Muscles responsible for shoulder adduction?

Answer 2

Lats, teres major, lower pec major

Question 3

Muscles responsible for shoulder flexion?

Answer 3

Anterior deltoid, upper pec major, coracobrachialis

Question 4

Muscles responsible for shoulder extension?

Answer 4

Lats, teres major, lower pec major, posterior deltoid

Question 5

Muscles responsible for internal rotation at shoulder?

Answer 5

Lats, teres major, pec major, subscapularis

Question 6

Muscles responsible for shoulder external rotation?

Answer 6

Infraspinatus, teres minor

Question 7

Muscles responsible for horizontal abduction at shoulder?

Answer 7

Lateral/posterior deltoid, infraspinatus and teres minor

Question 8

Muscles responsible for Horizontal adduction at shoulder?

Answer 8

Pec major, anterior deltoid and coracobrachialis

Question 9

Pectoralis major origin?

Answer 9

Anterior surface of clavicle (clavicular head)

Adjacent portion of sternum and costal cartilages of first six runs (sternal head)

Question 10

Pectoralis major insertion?

Answer 10

Both heads insert on the flat tendon 2-3 inches wide to the lateral lip of the intertubercular groove of the humerus

Question 11

Origin and insertion of coracobrachialis?

Answer 11

O- Coracoid process of scapula

I- medial border of humeral shaft

Question 12

Anterior deltoid origin and insertion?

Answer 12

O- anterior lateral third of clavicle

I- deltoid tuberosity on lateral humerus

Question 13

Latissimus Dorsi origin?

Answer 13

Posterior crest of ilium, back of sacrum, lumbar spinous process and lower 6 thoracic vertebrae

Question 14

Insertion of the latissimus Dorsi?

Answer 14

Medial lip of intertubercular groove of the humerus

Question 15

Origin of teres major?

Answer 15

Posteriorly on the lateral border of scapula

Question 16

Teres major insertion?

Answer 16

Medial lip of intertubercular groove of humerus (just posterior to lat insertion)

Question 17

Posterior deltoid origin and insertion?

Answer 17

O- spine of scapula

I - deltoid tuberosity on humeral shaft

Question 18

Supraspinatus origin and insertion?

Answer 18

O - supraspinous fossa

I - greater tubercle of the humerus

Question 19

Lateral deltoid origin and insertion?

Answer 19

O - acromion process

I - deltoid tuberosity on lateral surface of humeral shaft

Question 20

Infraspinatus origin and insertion?

Answer 20

O - scapula infraspinous fossa

I - middle facet on greater tubercle of humerus

Question 21

Teres minor origin and insertion

Answer 21

O - posteriorly on lateral border of scapula

I - posteriorly on greater tubercle of humerus

Question 22

Supraspinatus origin and insertion?

Answer 22

O - supraspinous fossa

I - greater tubercle of the humerus

Question 23

Lateral deltoid origin and insertion?

Answer 23

O - acromion process

I - deltoid tuberosity on lateral surface of humeral shaft

Question 24

Infraspinatus origin and insertion?

Answer 24

O - scapula infraspinous fossa

I - middle facet on greater tubercle of humerus

Question 25

Teres minor origin and insertion

Answer 25

O - posteriorly on lateral border of scapula

I - posteriorly on greater tubercle of humerus