lecture 7: Shoulder and Elbow

Question 1

What are the features that permit a wide range of motion for the shoulder joint? (LO1)

Answer 1

the articular surface of the humerus head is considerably larger than the glenoid fossa

Question 2

what is the common site of fracture in the head of the humerus?

Answer 2

surgical neck

Question 3

what is the name of the structure around the glenoid fossa that softens and deepens its edge?

Answer 3

glenoid labrum

Question 4

what muscles originate at the supraglenoid and infra glenoid tubercles?

Answer 4

supraglenoid tubercle- ‘O’ of the long head of bicep brachii
infra glenoid tubercle- ‘O’ of the long head of triceps

Question 5

Answer 5

Question 6

what are the rotator cuff muscles?

Answer 6

subscapularis, teres minor, supraspinatus, and infraspinatus

Question 7

Answer 7

Question 8

what ligament reinforces the shoulder joint capsule superiorly?

Answer 8

coracohumeral

Question 9

where do most shoulder dislocations happen?

Answer 9

anteriorly and inferiorly

Question 10

which ligament holds down the tendon of the long head of the bicep?

Answer 10

traverse humeral ligament

Question 11

Answer 11

Question 12

what is the role of

Question 13

what are the chief abductors of the shoulder?

Answer 13

Supraspinatus and deltoid(multipennate central fibres)

Question 14

which muscle prevents upward displacement of the head of the humerus?

Answer 14

teres minor and major

Question 15

what is the chief lateral rotator of the shoulder

Answer 15

infraspinatus
teres minor
Posterior deltoid

Question 16

what are the chief internal rotators(and adductors)?

Answer 16

subscapularis
pectoralis major
teres major
Latissimus dorsi

Question 17

what muscles flex the arm on the shoulder?

Answer 17

clavicular fibres of pec major
anterior fibers of deltoid

Question 18

what muscles extend the arm at the shoulder joint?

Answer 18

posterior fibers of deltoid latissimus dorsi
Teres major
Long head of triceps
Steenocostal portion of pectoralis major

Question 19

what is the weakest position of the shoulder joint

Answer 19

when the arm is abducted only the tendon of the long head of the triceps(which originates at the infra glenoid tubercle) is supporting the head of the humerus inferiorly.

e.g fall on extended arm

Question 20

‘O’ and ‘I’ of infraspinatus, supraspinatus, and teres minor

Answer 20

infraspinatus:

‘O’-infraspinous fossa
‘I’-middle facet of greater tubercle

Supraspinatus:

‘O’-supraspinous fossa
‘I’-superior facet of greater tubercle

Teres minor:
‘O’-lateral border of scapula
‘I’-inferior faceet of greater tubercle

Question 21

‘O’ and ‘I’ subscapularis

Answer 21

O:Subscapular fossa
I:lesser tubercle of humerus

Question 22

what nerve innervates teres minor?

Answer 22

axillary n

Question 23

what nerve innervates infraspinatus and supraspinatus?

Answer 23

subscapular nerve

Question 24

what nerve innervates subscapularis?

Answer 24

upper&lower subscapular n

Question 25

what is the action of the subscapularis

Answer 25

internally rotates the arm

Question 26

main function of supraspinatus

Answer 26

abduct the arm

Question 27

main function of infraspinatus and teres minor

Answer 27

externally rotate arm

Question 28

subscapularis: ant or post?

Answer 28

anterior

Question 29

what nerve innervates teres major?

Answer 29

lower subscapular nerve

Question 30

what is the order of insertions on the intertubercular groove?

Answer 30

most lateral-pec major middle-lat.dorsi most medial- teres major

Question 31

what are the bursas in the shoulder?

Answer 31

-subscapular bursa(lies under subscapularis tendon) -subcoracoid bursa( under coracoid) -subacromial bursa and subdeltoid bursa(continuation of each other)

Question 32

what provides active stabilisation of the shoulder ?

Answer 32

rotator cuff muscles

Question 33

what muscles are innervated by the suprascapular nerve?

Answer 33

supraspinatus, infraspinatus

Question 34

what does the subscapular nerve innervate?

Answer 34

subscapularis

Question 35

what are the flexor/extensor joints of the elbow?

Answer 35

Humero-ulnar joint Humero-radial joint

Question 36

what are the pronator/supinator joints of the elbow?

Answer 36

humero-radial superior radio-ulnar joint

Question 37

what is the area on the condyle that is part of the humero-ulnar joint?

Answer 37

trochlea

Question 38

Answer 38

Question 39

what are the components of the humero-radial joint?

Answer 39

capitulum superior surface of radius

Question 40

what is the function of the coronoid, olecranon, and radial fossas in the elbow?

Answer 40

increase the range of motion at the maximum flexion

Question 41

what is the role of ulnar and radial collateral ligaments in the elbow?

Answer 41

Ulnar prevent abduction of Ulna and Radial prevents adduction of radius

Question 42

where does the radial collateral ligament originate and insert?

Answer 42

O- lateral epicondyle I- anular ligament of radius

Question 43

what is the role of anular ligament of radius?

Answer 43

runs from edge of radial notch, wraps around the head of the radius allows the radius to rotate BUT prevents it from being pulled out inferiorly

Question 44

what is the function of the fat pads in the elbow?

Answer 44

Sit in the coronoid and olecranon fossas, reduce the amount of synovial fluid needed. Moved away during flexion.

Question 45

what happens if yank on a kid's arm too hard?

Answer 45

can pull the head of the radius through the anular ligament (because it takes a while to ossify) can pop it back in in adults- ossified and ligament is tough, so can cause more damage

Question 46

what is wrong here?

Answer 46

can see that the fat pads have moved out of the fossas potential fracture leaking blood into the joint space-> lifting the fat pads

Question 47

Answer 47

Question 48

arm abductors at the shoulder joint

Answer 48

supraspinatus deltoid middle part

Question 49

arm adductors at the shoulder joint

Answer 49

Question 50

arm flexors at the shoulder joint

Answer 50

Question 51

arm extensors at the shoulder joint

Answer 51

Question 52

internal and external rotators of the arm

Answer 52

internal: lat. dorsi teres major pec. major subscapularis anterior deltoid external: teres minor posterior deltoid infraspinatus