Glenohumeral joint

Question 1

GH joint type

Answer 1

synovial (diarthrosis) ball and socket

Question 2

GH joint degrees of freedom

Answer 2

3

Question 3

Positioning of GH fossa and humeral head

Answer 3

GH fossa is directed antero-laterally with slight upward rotation
Humeral head faces medially, posteriorly, and superiorly

Question 4

GH joint resting position (LPP)

Answer 4

55 degrees abd, 30 degrees horz add, slight ER

Question 5

GH CPP

Answer 5

max abd and ER (raised hand position)

Question 6

GH Capsular pattern

Answer 6

ER>abd>IR (order of limited motion “frozen shoulder”)

Question 7

degrees of GH flexion

Answer 7

120

Question 8

GH flexion: prime movers

Answer 8

-Anterior Deltoid
-Pectoralis Major (Clavicular Head to 60)
-Coracobrachialis
-Biceps Brachii

Question 9

GH Extension: degrees of movement

Answer 9

65

Question 10

GH Extension: prime movers

Answer 10

-Posterior deltoid
-Teres major
-Latissimus dorsi
-Long head of triceps
-Pectoralis major (sternocostal portion from 180-90)

Question 11

GH ABD: degrees of motion

Answer 11

120 (when in ER)

Question 12

GH ABD: prime movers

Answer 12

-supraspinatus (first 30)
-lateral deltoid (all contribute)

Question 13

GH ADD: degrees of movement

Answer 13

0 pure add; 50-75 add in front of body

Question 14

GH ADD: prime movers

Answer 14

-Posterior deltoid
-Anterior deltoid
-Pectoralis major
-Long head of triceps
-Coracobrachialis
-Teres major
-Latissimus dorsi

Question 15

GH ER: degrees of movement

Answer 15

60-70 of pure ER
90 when shoulder is abducted

Question 16

GH ER: prime movers

Answer 16

-Posterior deltoid
-Teres minor
-Infraspinatus
-Supraspinatus (between neutral and full ER)

Question 17

GH IR: degrees of movement

Answer 17

75-85

Question 18

GH IR: prime movers

Answer 18

-Anterior deltoid
-Pectoralis major
-Teres major
-Latissimus dorsi
-Subscapularis

Question 19

Arthrokinematics: Flexion

Answer 19

(mostly spinning)
convex on concave
roll in an anterior direction and glide in a posterior direction
(at end range direction may switch)

Question 20

Arthrokinematics: Extension

Answer 20

(mostly spinning)
roll posterior and glide anterior

Question 21

Arthrokinematics: abduction

Answer 21

humerus rolls superior while gliding inferior
(without glide there would be impingement of structures under the acromial arch)

Question 22

Arthrokinematics: add

Answer 22

humeral head rolls inferiorly while gliding posteriorly

Question 23

Arthrokinematics: ER

Answer 23

humeral head rolls posterior and glides anterior
(without glide the humerus would roll posteriorly out of the socket)

Question 24

Arthrokinematics: IR

Answer 24

humeral head rolls anteriorly and glides posteriorly

Question 25

GH: stabilizing structures

Answer 25

-Rotator cuff muscles -Capsule -GH ligaments -Coracohumeral ligament -Coracoacromial arch -Long head of the biceps -Glenoid labrum -Negative intra-articular pressure -Compressive forces

Question 26

GH: rotator cuff muscles and function

Answer 26

S: supraspinatus I: infraspinatus T: teres minor S: subscapularis -provide static stability through reinforcement of the capsule and most of the dynamic stability -produce an inferiorly directed force on the HH

Question 27

loose/expandable space lined with synovium that provides GH stability

Answer 27

capsule

Question 28

GH ligaments

Answer 28

-Superior GH lig -Middle GH lig -Inferior GH lig

Question 29

Superior GH ligament taut position

Answer 29

arm at side or with inferior and posterior translation of the humerus

Question 30

Middle GH ligament: function and most effective position

Answer 30

-restricts anterior translation of the GH and resists ER -most effective: 45-60 degrees of ABD

Question 31

Prevents anterior translation of GH with arm ABD to 90 degrees or greater (strongest and thickest part of entire capsule)

Answer 31

anterior band of inferior GH ligament

Question 32

prevents posterior translation of the GH with arm ABD to 90 degrees or greater

Answer 32

posterior band of the inferior GH ligament

Question 33

portion of the inferior GH ligament that is taut in more than 90 degrees of ABD

Answer 33

axillary pouch

Question 34

limits inferior displacement of the GH with arm at side and checks extremes of ER when shoulder is in ADD

Answer 34

coracohumeral ligament

Question 35

Parts of the coracoacromial arch and function

Answer 35

-coracoid, acromion, and coracoacromial lig -prevents humerus from dislocating superiorly

Question 36

structures under the coracoacromial arch

Answer 36

- Rotator cuff tendons - Long Head of Bicep - Subacromial Burs - Subdeltoid Bursa

Question 37

has attachment to labrum, plays a role in humeral head depression and limiting excessive anterior translation

Answer 37

long head of the biceps

Question 38

deepens the glenoid fossa providing increased stability

Answer 38

glenoid labrum

Question 39

can be lost if capsule is punctured

Answer 39

negative intra-articular pressure

Question 40

how are compressive forces created in the GH joint

Answer 40

due to upward orientation of the scapula, the force vectors of gravity, and the superior GH restraints

Question 41

orientation of scapular plane

Answer 41

30-45 degrees towards the sagittal plane

Question 42

ratio of scapulohumeral rhythm

Answer 42

2 GH joint :1 ST joint

Question 43

scapulohumeral rhythm for full arm elevation (degrees)

Answer 43

120 degrees of shoulder abd and 60 degrees of upward rotation

Question 44

role of scapular movement

Answer 44

-maintains glenoid fossa in optimal position -allows muscles to maintain good length-tension relationship -allows for increased ROM

Question 45

force couple of scapular upwards rotation

Answer 45

upper trapezius lower trapezius serratus anterior

Question 46

scapulohumeral rhythm with less than 90 degrees ABD

Answer 46

60° of ABD at GH and 30° of scapular rotation

Question 47

clavicular elevation at the SC joint with less than 90 degrees ABD

Answer 47

20-25 degrees

Question 48

upward rotation of acromion at the AC joint with less than 90 degrees of ABD

Answer 48

5-10 degrees

Question 49

clavicular elevation at the SC joint with more than 90 degrees ABD

Answer 49

5 degrees

Question 50

upward rotation of acromion at the AC joint with more than 90 degrees of ABD

Answer 50

20-25 degrees

Question 51

posterior rotation of the clavicle with more than 90 degrees of shoulder ABD

Answer 51

40 degrees