Deck 7: The Shoulder Complex

Question 1

What is the most frequent direction of glenohumeral (GH)dislocation? What position of the humerus puts the joint at greatest risk for dislocation?

Answer 1

Anterior between the superior and middle GH ligaments.Because of the orientation of the head and fossa,the most common dislocation of the humeral head occurs anteriorly.Bringing the humerus into abduction and external rotation puts the humeral head in a position where it can most readily be thrust forward through the capsule.Although the inferior axilla is least protected,inferior dislocations generally would occur from a force from above,an area protected by the coracoacromial arch.The posterior axilla is well protected by musculature.The anterior joint has neither bony protection nor the muscular mass of the posterior axilla.There is also a common area of marked weakness in the anterior joint capsule that will fail with sufficient imposition of force.

Question 2

Which of the following muscles assists in counteracting the upward translatory force caused by the deltoid muscle at the glenohumeral joint?

A) Supraspinatus
B) Serratus anterior
C) Coracobrachialis
D) Teres minor

Answer 2

D

Question 3

Which structure directly produces the posterior rotation of the clavicle needed for normal shoulder girdle elevation?

A) The conoid portion of the coracoclavicular ligament
B) The coracohumeral ligament
C) The subclavius muscle
D) The anterior fibers of the deltoid muscle

Answer 3

A

Question 4

Which of the following best describes motion at the sternoclavicular (SC)joint?

A) During clavicular elevation and depression,the disc of the SC joint moves with the medial end of the clavicle on the manubrial facet.
B) During clavicular protraction and retraction,the disc of the SC joint moves with the medial end of the clavicle on the manubrial facet.
C) During clavicular elevation and depression,the lateral end and medial end of the clavicle move in the same direction.
D) During clavicular protraction and retraction,the lateral end and medial end of the clavicle move in opposite directions.

Question 5

Elevation of the clavicle at the sternoclavicular joint involves osteokinematic motion of the clavicle in the ________________direction and arthrokinematic motion of the joint surface in the ________________direction.

A) inferior,superior
B) inferior,inferior
C) superior,inferior
D) superior,superior

Question 6

Which of the supporting ligaments of the glenohumeral (GH)joint is considered to be a "ligament complex"?

A) The inferior GH ligament
B) The middle GH ligament
C) The superior GH ligament
D) The coracoacromial ligament

Question 7

Scapular movements that take place at the acromioclavicular joint include ________________tipping that occurs around a ________________axis and ________________that occurs around a ________________axis.

Question 8

Why is the supraspinatus able to abduct the shoulder without additional muscular synergy?

Question 9

What are the advantages to the coracoacromial arch? What are the disadvantages?

Question 10

The ultimate function of motion at the scapulothoracic joint is to:

A) Orient the glenoid fossa for optimal contact with the humeral head when maneuvering the arm.
B) Provide downward rotation during shoulder girdle elevation.
C) Decrease stability at the acromioclavicular (AC)and sternoclavicular (SC)joints.
D) Work independent of the glenohumeral (GH)motion.

Question 11

Which muscle(s)stabilize(s)the scapula in order to allow normal function of the teres major muscle?

A) Levator scapula
B) Supraspinatus
C) Rhomboids
D) Upper trapezius
Completion
Complete each statement.

Question 12

When a tennis player elevates her shoulder during a serve,the clavicle rolls in a(n)________________direction and glides in a(n)________________direction on the clavicular notch at the sternoclavicular joint.

A) superior,superior
B) inferior,inferior
C) superior,inferior
D) inferior,superior

Question 13

The external rotation that occurs at the glenohumeral joint after 80° to 90° of abduction produces a(n)________________roll and a(n)________________glide of the humeral head on the glenoid fossa.

A) posterior,posterior
B) anterior,anterior
C) anterior,posterior
D) posterior,anterior

Question 14

The acromioclavicular (AC)joint contributes to shoulder elevation ____________________.

A) between 30° and 90° of abduction when tension on the trapezoid component of the coracoclavicular ligament produces a posterior rotation of the clavicle
B) after 90° of shoulder abduction and until all scapulothoracic motion is taken up
C) between 30° and 90° of abduction when anterior rotation of the clavicle allows for 30° of scapular upward rotation
D) after 60° of abduction

Question 15

What accounts for the static stability of the glenohumeral (GH)joint when the arm is at the side? What happens if you excessively load the hanging (dependent)limb?

Question 16

Which of the following is a function of the rotator cuff during shoulder girdle elevation?

A) Functions with the deltoid to produce a superior translation of the humeral head during shoulder girdle elevation
B) Produces scapular upward rotation during shoulder girdle motion
C) Balances the deltoid activity by providing a slight inferior translatory force of the humeral head during shoulder girdle elevation
D) Produces downward rotation of the scapula during shoulder girdle motion

Question 17

Anterior scapular tipping is normally ________________from vertical and directly affects motion at the ________________joint.

A) 10° to 15°,glenohumeral
B) 10° to 15°,acromioclavicular
C) 35° to 45°,glenohumeral
D) 35° to 45°,acromioclavicular

Question 18

The ________________ligament is the primary stabilizer of the sternoclavicular joint.

A) interclavicular
B) coracoclavicular
C) costoclavicular
D) sternoclavicular

Question 19

Which of the following best describes the structure of the glenohumeral (GH)joint?

A) The joint surfaces of the GH joint are naturally congruent and stable.
B) The glenoid labrum enhances the depth of the glenoid fossa.
C) The glenoid fossa,by itself,is three times larger than the humeral with which it articulates.
D) The glenoid labrum is a thin hyaline cartilage structure.

Question 20

Which of the following muscles produce upward scapular rotation when the shoulder girdle is elevated from 90° to 180°?

A) Deltoid and rotator cuff muscles
B) Upper trapezius,lower trapezius,and serratus anterior
C) Upper trapezius and serratus anterior
D) Teres major and teres minor

Question 21

What muscular synergy does the teres major require to perform its function?

Question 22

How would range and strength of abduction of the upper extremity be affected if there were paralysis of the infraspinatus,teres minor,and subscapularis muscles?

Question 23

How would range and strength of abduction of the upper extremity be affected if the sternoclavicular joint were fused?

Question 24

How would range and strength of abduction of the upper extremity be affected if there were a rupture of the coracoclavicular ligament?

Question 25

How would range and strength of abduction of the upper extremity be affected if there were paralysis of the deltoid muscle?