Shoulder

Question 1

What is the role of the disc in the SC joint

Answer 1

promotes congruency (stability) since clavicle and manubrium are incongruent

Question 2

what shape is the SC joint in at rest?

Answer 2

wedge shaped and opened superiorly

Question 3

interclavicular ligament function

Answer 3

limits depression and superior glide (picture clavicle like a door handle for this)

Question 4

posterior and anterior sternoclavicular ligament function

Answer 4

limits protraction/ retraction (therefor restricting ant and post translation)

Question 5

costoclavicular ligament

Answer 5

limits elevation which contributes to inferior slide of the medial clavicle in elevation, and shock absorbtion

Question 6

arthrokinematics of elevation and depression at the SC joint

Answer 6

CONVEX ON CONCAVE
elevation: superior roll, inf slide
depression: inferior roll, superior slide

Question 7

arthrokinematics of PROTRACTION and RETRACTION at the SC joint

Answer 7

CONCAVE ON CONVEX
Protraction- Anterior roll and slide
Retraction- posterior roll and slide

Question 8

arthrokinematics of ANT/ POST ROTATION at the SC joint

Answer 8

POST ROTATION: inf surface turns ant
ANT ROTATION: returns to inferior position (rotates posterior but stops once it gets to base position- we ONLY do this coming back from post rotation)

Question 9

in the AC joint, are surface congruent?

Answer 9

NO, but not always disc

Question 10

primary function of SC joint

Answer 10

allow scapula to rotate arm during mvmt, and positions glenoid beneth the hummerus head

Question 11

explain what the scapular plane is

Answer 11

the scapula is angled to maintrain congruency with the thorax

Question 12

describe the joint capsules at the SC and AC and glenohumoral joints:

Answer 12

SC: posterior portion restraints anterior and posterior translation of clavicle
AC: weak, requires reinforcement
GH: laxity, min stability, reinforced by thicker external ligaments, inferior portion is locked in a ducted position creating axillary pouch

Question 13

acromioclavicular ligament

Answer 13

resists anterior clavicular

Question 14

coracoclavicular ligament

Answer 14

restrians inferior translation of acromian, posterior translation of clavicle, and limits upward rotation of scapula

Question 15

why is internal and exsternal rotation of the scapula important and explain what it looks like

Answer 15

important for maintaining contact of scapula on curved thorax during protractinon and retraction of clavicle

IR- glenoid fossa is ant with CLAVICLE PROTRACTION

ER- glenoid fossa is post with CLAVICLE RETRACTION

Question 16

why is upward and downward rotation of the scapula important and coupled movments

Answer 16

important for positioning glenoid fossa in the optimal position

Upward rotation- shuolder abduction and flexion

downward rotation- shoudler adduction or exstention

Question 17

anterior/ posterior tipping of the scapula coupled movments

Answer 17

ant tilt- elevation of clavicle
post tilt- depression of clavicle

Question 18

explain what happens to have a dislocated AC joint

Answer 18

force directly on the shoulder dislocated AC joint
sloped nature makes it susceptible

Question 19

what does the scapulothorastic joint depend on

Answer 19

SC and AC joints

Question 20

what coupled motions happen at the scapula to provide elevation

Answer 20

SC elevation and AC downward rotation

Question 21

what coupled motions happen at the scapula to provide upward rotation

Answer 21

SC elevation and AC upward rotation

Question 22

what coupled motions happen at the scapula to provide protraction/ retraction

Answer 22

SC protraction and slight AC IR (angle)

Question 23

superiorglenohumeral ligament

Answer 23

limits ant and inferior translation when hand at side

Question 24

middle glenohumoral ligament

Answer 24

limits anterior translation with the arm at the side and up to 60 degrees of ABD

Question 25

inferior glenohumoral ligament

Answer 25

anterior band, posterior band, axillery pouch - primary stabilizer beyond 45 degrees of abduction or with ocmbined abd and rotation abduction- axillary pouch resists inf translation- 1st pic abduction and lateral rotation- anterior band resists anterior translation and inferior translation- 2nd pic abduction and medial rotation- post band resists post and inferior translation

Question 26

coracohumoral ligament

Answer 26

limits inferior translation and external rotation of the humeral head

Question 27

what is the glenoid labrum-

Answer 27

ring of cartilage around the glenoid cavity enhances concavity and increases articular surface

Question 28

hummoral retroversion and throwing athletes

Answer 28

hummoral retroversion- backward rotation of the humeral head (the upper arm bone) relative to the axis of the humerus increased hummoral retroversion results in increased ER and reduced IR

Question 29

relationship between tifht posterior capsule and shoulder impingement

Answer 29

tightness in the posterior shoulder capsule may produce increased anterior humeral head translation which in turn decreases the subacromial space cuasing shoulder impingement