Lecture 5: Scapula and Shoulder

Question 1

Shoulder complex needs to be able to provide mobility while at the same time supply stability to position hand in space where it can be effective at tasks

Answer 1

Dynamic stability concept

Question 2

T/F: shoulder complex provides both stability and mobility

Answer 2

true

Question 3

Orients the glenoid fossa and provides stable base for ball and socket movements of glenohumeral joint are two functions of the _____.

Answer 3

scapula

Question 4

only bony connection of the UE to the trunk; plane synovial joint that allows gliding motions in 3 planes of motion; very strong joint capsule

Answer 4

sternoclavicular joint

Question 5

What are the 3 ligaments in the sternoclavicular joint?

Answer 5

1. sternoclavicular ligament
2. costoclavicular ligament
3. interclavicular ligament

Question 6

What are the 2 ligaments in the acromioclavicular joint?

Answer 6

1. acromioclavicular ligament

2. coracoclavicular ligament

Question 7

Joint that maintains the relationship between the scapula and the clavicle

Answer 7

acromioclavicular joint

Question 8

This joint is not a true anatomic joint, however, it does maintain a direct relationship of the scapula to the thorax as the scapula slides along the ribs

Answer 8

scapulothoracic joint

Question 9

T/F: scapular stability is provided by structures that maintain integrity of adjacent joints as well as by the muscles that help to hold the scapula to the thorax

Answer 9

true

Question 10

T/F: The glenohumeral joint has so much mobility, so it is at little risk for becoming unstable

Answer 10

False - higher risk bc of the extra mobility

Question 11

Two functions of the ______ are

1. deepen the curve of the glenoid fossa thus increasing the articular surface with the humeral head
2. cushions the head of the humerus

Answer 11

glenoid labrum

Question 12

What is this describing?

1. taut superiorly and slack inferiorly in resting position
2. laxity is necessary for the large excursion of joint surfaces
3. trade off is that the laxity provides little joint stability

Answer 12

glenohumeral capsule

Question 13

This glenohumeral ligament provides the important function of providing passive support of the upper limb against the force of gravity

Answer 13

coracohumeral ligament

Question 14

What are the ligaments of the glenohumeral capsule?

Answer 14

1. glenohumeral ligament
2. coracohumeral ligament
3. coracoacromial ligament

Question 15

This glenohumeral ligament helps to form a secondary arch over the joint and prevents upward dislocation of the head of the humerus

Answer 15

coracoacromial ligament

Question 16

Main function is to allow the smooth gliding of lower structures on upper structures without friction

Answer 16

bursae - specifically subdeltoid and subacromial

Question 17

This protects the humeral head as well as the sensitive muscles, tendons, and bursar overlying the head from direct trauma; prevents dislocation of the humerus superiorly

Answer 17

coracoacromial arch (acromion and coracoacromial ligament)

Question 18

Name the 7 movements of the scapula/shoulder

Answer 18

1. elevation
2. depression
3. abduction (protraction)
4. adduction (retraction)
5. upward rotation (acromion process moves up)
6. downward rotation (acromion process moves down)
7. upward tilt (extreme hyperextension)

Question 19

Scapular elevation, depression, abduction, and adduction are _________ motions

Answer 19

translatory (all points on the scapula moving along parallel lines)

Question 20

Scapular upward rotation and downward rotation are _______ motions.

Answer 20

rotary

Question 21

The two purposes of __________ _______ are

1. maintain glenoid fossa in optimal position to receive head of the humerus increasing maximum ROM
2. motion of scapula permits muscles acting on humerus to maintain good length-tension relationship

Answer 21

Scapulohumeral rhythm

Question 22

Out of a maximum 180 degrees of shoulder flexion or abduction, we really have _____ degrees of glenohumeral motion and ______ degrees of scapular motion

Answer 22

100-120 and 60

Overall ratio is 2:1 (2 degrees of humeral movement to 1 degree of scapular movement)

Question 23

Describe scapular movement on thorax (3 main steps) - scapulothoracic motion

Answer 23

1. first 30 degrees of motion occurs through action at the sternoclavicular joint
2. at 30 degrees of elevation of the clavicle, the costoclavicular ligament becomes quite taut and prevents further elevation of the clavicle
3. when the lateral end of the clavicle rotates in this direction, it allows the scapula to rotate the final 30 degrees

Question 24

T/F: In therapy, it is important to know that the arm cannot be fully flexed without accompanying scapulothoracic motion

Answer 24

true

Question 25

T/F: if there is damage to the sternoclavicular ligament, the clavicle cannot elevate and therefore the scapula cannot begin to rotate

Answer 25

true

Question 26

Prime mover for abduction and upward rotation of the scapula; without this muscle, scapula will wing

Answer 26

serratus anterior

Question 27

Contraction of this muscle lifts the shoulder in elevation

Answer 27

trapezius

Question 28

Trap __ is a prime mover for the elevation of the scapula

Answer 28

Trap I | top portion of trap on the back of the neck

Question 29

Trap __ is a prime mover for the elevation and upward rotation of the scapula. It also assists with adduction of the scapula

Answer 29

Trap II | middle portion of trap on the lower neck and extending on the top of the shoulder

Question 30

Trap __ is a prime mover for adduction of scapula

Answer 30

Trap III | middle portion of trap across the upper middle of the back

Question 31

Trap __ is a prime mover for depression and upward rotation of the scapula. Also assists with adduction of the scapula

Answer 31

``` Trap IV (bottom portion of trap that extends down the back) ```

Question 32

This muscle is prime mover for adduction and also assists with downward rotation and elevation of the scapula

Answer 32

rhomboids

Question 33

This muscle is prime mover for scapular elevation

Answer 33

levator scapulae

Question 34

By pulling on the coracoid process, this muscle is prime mover for downward rotation and depression of the scapula

Answer 34

Pectoralis major

Question 35

Without both the ______ and _____ muscles, the scapula is positioned in downward rotation and wings quite substantially

Answer 35

serratus anterior and trapezius

Question 36

Trap III and rhomboids are _________ when scapula is adducting

Answer 36

agonists

Question 37

Traps I and II perform major ________ functions of the clavicle and scapula

Answer 37

stabilization

Question 38

Neutralizing muscles: | Elevation caused by traps __ and __ and rhomboids are cancelled out by depression of trap ___. Result is adduction

Answer 38

Traps 1 and 2; trap 4 Trap 1, 2, and 4 and rhomboids are neutralizing synergists

Question 39

Traps __ and __ upwardly rotate scapula whereas _____ downwardly rotate scapula. In adduction, these motions are neutralized.

Answer 39

2 and 4; rhomboids All of the above are neutralizing synergists

Question 40

Trap __ is a prime mover for scapular adduction and ______ _____ is a prime mover for scapular abduction

Answer 40

trap 3; serratus anterior They are antagonists

Question 41

two or more forces whose points of application occur on opposite sides of an axis and in opposite directions to produce rotation

Answer 41

force couples

Question 42

Force couple of trap 2 and 4: | as a force couple you would also get some adduction of the scapula in addition to upward rotation

Answer 42

elevation of trap 2 is canceled out by depression of trap 4

Question 43

Force couple of trap 2 and serratus

Answer 43

you would get upward rotation as well as elevation and abduction

Question 44

Force couple of trap 4 and serratus

Answer 44

upward rotation as well as abduction and depression

Question 45

T/F: It is only with action of all three muscles that pure upward rotation is achieved due to neutralizing synergies that cancel out other movements

Answer 45

True