Shoulder Joint

Question 1

Latissimus dorsi

Answer 1

Action- extends arm from flexed position adducts arm from abducted position
Origin - posterior crest of ilium
Insertion- medial side of humerus

Question 2

Teres major

Answer 2

Actions - extends shoulder, assists in adduction

Origin - inferior lateral border scapula

Question 3

Deltoid

Answer 3

Anterior fibres
Actions - abduct, flex, horizontally adduct, internally rotate shoulder
Origin- anterior border and superior surface of scapula
Insertion- lateral surface of humerus

Middle fibres
Action- abduct shoulder
Origin- lateral border of acromium process
Insertion- lateral surface of humerus

Posterior fibres
Action - abduct, extend, horizontally abduct, externally rotate shoulder
Origin- inferior border of scapula
Insertion - lateral surface of humerus

Question 4

Pectoralis major

Answer 4

Upper fibres
Actions - internal rotation, flexion of shoulder
Origin - medial half of clavicle
Insertion- lateral lip of bicipital groove of humerus

Question 5

Teres minor

Answer 5

Actions - lateral rotation of arm
Origin - posterior surface of scapula
Insertion - inferior facet on greater tubercle of humerus

Question 6

Supraspinatus

Answer 6

Actions - initiates abduction to 15 degrees after this deltoid stake over
Origin - supraspinatus fossa of scapula
Insertion- most superior facet on greater tubercle of humerus

Question 7

Infraspinatus

Answer 7

Actions- lateral rotation of shoulder
Origin- posteriorly on upper and middle of lateral border of scapula
Insertion - posterior aspect on greater tubercle of humerus

Question 8

Subscapularis

Answer 8

Actions- internal rotation, adduction and extension of shoulder
Origin- entire anterior surface of subscapular fossa
Insertion - lesser anterior tubercle of humerus