lecture 9: the shoulder

Question 1

which 2 bones form the glenohumeral joint

Answer 1

scapula and humerus

Question 2

know all the landmarks of the scapila

Answer 2

.

Question 3

what are the 2 tubercles of the humerus

Answer 3

lesser and greater

Question 4

which tubercle facest more laterally

Answer 4

greater tubercke

Question 5

which neck is more superior: anatomical or surgical

Answer 5

anatomical

Question 6

what sits between the 2 tubercles

Answer 6

intertubercular groove

Question 7

what is the orientation of the deltoid tuberocity

Answer 7

lateral

Question 8

be able to name the landmarks on the hum

Answer 8

,

Question 9

what type of joint is the glenohum joint

Answer 9

multiaxial ball and socket jt

Question 10

what are the directins of the multiaxial ball and socket gleno joint

Answer 10

in both direcitons in 3 planes and the combo of these

Question 11

what makes the gleno jt so mobile

Answer 11

it is a big ball (humeral head) in a small, shallow socket (glenoid fossa)

Question 12

how much smaller is the glenoid fossa in comparison to the humeral head

Answer 12

3-4 times smaller

Question 13

what are the motions of the glenohumeral joint

Answer 13

flexion, extension
abduction/adduciton
lateral/medial rotation

Question 14

explain the cost of a highly mobile shoulder

Answer 14

multiaxial, large ROM with a shallow/ill fititng ball and socket

=instabilitiy

Question 15

explain the cost of a highly mobile shoulder

Answer 15

multiaxial, large ROM with a shallow/ill fititng ball and socket

=instabilitiys

Question 16

since there isso much instability of the gleno joint, what is needed

Answer 16

passive and active stab structures

Question 17

what are the general passive stabilizers of the glenohum jt

Answer 17

glenoid labrum and ligaments

Question 18

what is the glenoid labrum and its fucntion

Answer 18

the rim of fibrocartilage around the edge of the glenoid fossa that deepens the fossa and increases contact area

Question 19

true or false: other mammals lack the gelnoid labrum

Answer 19

true

Question 20

what surface do the glenohumeral ligaments reinforce

Answer 20

reinforce on the anterior/intferior surface

Question 21

what surface do the coracohumeral ligaments support

Answer 21

the siperior aspect

Question 22

true or false: the posterior surface of the gleno jt has many ligaments

Answer 22

false, has no ligaments

Question 23

what are the important ligaments of the gleno jt

Answer 23

coracohum
glenohum

Question 24

how many glenohumeral ligamnets are there

Answer 24

3

Question 25

where does to the coracohumeral ligament attach

Answer 25

the greater tubercle of the huemrus

Question 26

true or false: the shoudler is th emost commonly dislocated large jt

Answer 26

true

Question 27

are there more anterior or posterior shoulder dislocations

Answer 27

95% are anterior dislocations

Question 28

when there is an anterior discloation, what is the postion of the humeral head

Answer 28

in the subcoracoid position

Question 29

what causes shoulder dislocations (MOI)

Answer 29

blunt force to abducted, extended and/or laterally rotated arm (ex: contact sports and overhead sports) =torque applied to distal which causes rotation (ant lig acts as a hinge)

Question 30

what is the main active stabilization of the shoulder

Answer 30

rotator cuff muscles

Question 31

what are the 4 RC muscles

Answer 31

4 muscles that originate on scapula, wrap around shoulder joint capsule and insert on the tubercles of proximal humerus

Question 32

where do the RC insert

Answer 32

the tubercles of the humerus

Question 33

explain how the RC muslcles provide shoulder mobility and active stability

Answer 33

by pulling the humeral head against the glenoid fossa

Question 34

true of false: the RC cause passive stabilization

Answer 34

false, active

Question 35

what are the 4 RC muslces (sits)

Answer 35

supraspinatus infraspinatus teres minor subscapularis

Question 36

which RC lkes anterior

Answer 36

subscapularis

Question 37

what is the origin of the supraspinatus m

Answer 37

supraspinous fossa

Question 38

what is the insertion of the supraspinatus m

Answer 38

greater tubercle (sup facet)

Question 39

where does the supraspinatus run

Answer 39

beneath acromion and over the glenoid fossa

Question 40

what is the function of the supraspinatus

Answer 40

abduction (esp. early/initiation)

Question 41

where is supraspinatus most commonly used

Answer 41

overhead sports and occupations

Question 42

what is the origin of the infraspinatus

Answer 42

infraspinous fossa

Question 43

what is the orogin of the teres minor

Answer 43

inferior border of the scapula

Question 44

what is the insterion of the infraspinatus

Answer 44

greater tubercle (middle facet)

Question 45

what is the insertion of the teres minor

Answer 45

greater tubercle (inf facet)

Question 46

what is the motion/action of the tere minor and infraspinatus

Answer 46

lateral rotation adduction (teres=weak)

Question 47

what is the origin of the subscap

Answer 47

subscapular fossa

Question 48

what is the insertion of the subscap

Answer 48

lesser tubercle of the humerus

Question 49

what is the action of the subscap

Answer 49

medial rotation (primary) adduction (weak)

Question 50

what is RC tendinitis

Answer 50

inflammation of the RC tendons

Question 51

what are the main causes of RC tendinitis

Answer 51

wear and tear, age, often due to overuse and friction of overhead motions

Question 52

where is RC tendinitis most common

Answer 52

supraspinatus

Question 53

why is RC tendinitis most common in supraspinatus

Answer 53

it is bounded superiorly by acromion and coracoacromial ligament (very narrow subacromial space)

Question 54

RC tendinitis is assocaited with what other condition

Answer 54

shoulder impingement syndrome

Question 55

what is shoulder impingement syndrome

Answer 55

irritation due to the pinching of the supraspinatus tendon in motion

Question 56

what is the painful arc test

Answer 56

abduction painful between 60 and 120 degrees

Question 57

which ligament forms a roof over the supraspinatus

Answer 57

coracoacromial

Question 58

be able to explain RC tendinitis

Answer 58

.

Question 59

true or false: Rc muscles are considered scapulohumeral muscles

Answer 59

true

Question 60

is deltoid a scapulohumeral muscles

Answer 60

yes

Question 61

what is the origin of the deltoid muscles

Answer 61

clavicle, acromial and spinal

Question 62

what is the insertion of the deltoid m

Answer 62

deltoid tuberocity of hum

Question 63

what is the action of the anterior/clavicular fibers of the detloid

Answer 63

flexion

Question 64

what is the action of the lateral/acromial fibers of the detloid

Answer 64

abduction

Question 65

what is the action of the psoterior/spinal fibers of the detloid

Answer 65

extension

Question 66

what is a common condition assocaited withdeltoid m

Answer 66

subacromial/subdeltoid m

Question 67

what are bursea

Answer 67

thin, fluid filled sacs between tisses (ex: muscles, bones and ligs)

Question 68

what is the function of bursae

Answer 68

reduces friction between the tissues

Question 69

what is SA/SD bursitis

Answer 69

inflammation and swelling of bursa, further narrowing subacromial space

Question 70

what is another expression of impingement syndrome (with sim symptoms)

Answer 70

SA/SD bursitis

Question 71

what are the subacromial and subdeltoid bursae

Answer 71

large, connected shoudler bursae, superior and lateral to humeral head =b/w deltoid m and tendon of supraspinatus

Question 72

what is the anatomical position of the SA and SD bursa

Answer 72

superior and lateral

Question 73

where are the SA and SD bursae located

Answer 73

between deltoid m and tendon of supraspinatus

Question 74

what is the scapulohumeral SH rhythm

Answer 74

collaborative movement between the scapulothoracic and glenohum jtn

Question 75

what is SH ryhtm ration

Answer 75

2:1 ratio of glenohum to scapulothoracic movement respectively

Question 76

where does most os shoulder movement come from

Answer 76

the glenohum joint (aided by the scapulothoracic jt)

Question 77

explain the scapulohumeral (SH) rhythm

Answer 77

first 30 degrees of abduction: movement occurs at glenohum jt beyond 30 degrees: further shoudler abduction is possible due to the concurrent movemetns at the sternoclav and scapulothoracic jts

Question 78

true or false: teres major is not a scapulohumeral muscle

Answer 78

false, it is

Question 79

what is the origin if the teres major

Answer 79

inferior angle of the scapula

Question 80

what is the insertion of the teresm= major

Answer 80

crest of lesser tubercle of humerus (medial)

Question 81

why does teres major do medial rotation

Answer 81

because it begins posteiror and crosses anterior

Question 82

what are the actions of the teres major

Answer 82

adduction, medial rotation extension (when shoudler flexed)

Question 83

when does teres major do extension

Answer 83

when shoulder is flexed

Question 84

what are the scapulohumeral muscles

Answer 84

RC,deltoid teres major coracobrach

Question 85

what is the origin of the coracobrach

Answer 85

tip of the coracoid process

Question 86

what is the isnertion of the coracobrach

Answer 86

medial humerus (1/2 way down)

Question 87

what is the action of the coracobrach

Answer 87

flexion, adduction medial rotation (weak)

Question 88

is the coracobrach a primary medial rotator

Answer 88

no false

Question 89

what are the thorax muscles with shoulder actions

Answer 89

lat dorsi pectoralis major

Question 90

what is the orogin of the lat dorsi

Answer 90

iliac crest, thoracolumbar fascia T7-T12 vert

Question 91

what is the insertion of the lat dorsi

Answer 91

floor of humerus intertubercular groove

Question 92

what is the origin of the pec major

Answer 92

clavicle, sternum, and ribs

Question 93

what is the insertion of the pec major

Answer 93

crest of greater tubercle (most lateralO)

Question 94

what are the actions of the pec major and lat dorsi at the shoulder

Answer 94

adduction medial rotation (extension when shoulder flexed)

Question 95

true or false: the pec major and lat dorsi only have action at the shoulder and back

Answer 95

false, they also cross the scapulothoracic joint therefore move the scapula too

Question 96

what motion at the scap does the pec major do

Answer 96

protraction (downward rot)

Question 97

what motion at the scap does the lat dorsi do

Answer 97

retraction (downward rot)

Question 98

what are the 3 muscles that insert into the intertub groove (lat to medial )

Answer 98

pec major lat dorsi teres major