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Flashcards in Muscles of the Shoulder Deck (35)
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1
Q

What are the superficial extrinsic shoulder muscles?

A

Latissimus Dorsi

Trapezius

2
Q

What nerve causes motor innervation of the Trapezius muscle?

A

The accessory nerve

3
Q

What causes sensory innervation of the Trapezius muscle?

A

C3 and C4 spinal roots

4
Q

What is the main action of the upper fibres of the Trapezius?

A

Elevate the scapula and rotate it during abduction of the shoulder

5
Q

What is the main action of the middle fibres of the Trapezius?

A

Retract the Scapula

6
Q

What is the main action of the lower fibres of the Trapezius?

A

Pull the Scapula inferiorly

7
Q

How can you test the function of the accessory nerve?

A

See how the Trapezius muscle functions by asking the patient to elevate the shoulder against resistance.

8
Q

What nerve innervates Latissimus Dorsi?

A

The thoracodorsal nerve

9
Q

What are the main actions of Latissimus Dorsi?

A

Extension of the arm at the shoulder
Adduction at the shoulder
Medial rotation of the arm

10
Q

What are the deep extrinsic muscles of the shoulder?

A

Levator scapulae

Rhomboids

11
Q

What nerve innervates the Levator scapulae?

A

The Dorsal scapular nerve

12
Q

What are the main actions of the Levator scapulae?

A

Elevates scapula

Rotates scapula to tilt the Glenohumeral joint inferiorly

13
Q

What are the two Rhomboid muscles?

A

Rhomboid major

Rhomboid minor

14
Q

What innervates the Rhomboid muscles?

A

The Dorsal scapular nerve

15
Q

What are the actions of the Rhomboid muscles?

A

Retracts the scapula
Fix scapula to thoracic wall
Rotates scapula to tilt the Glenohumeral joint inferiorly

16
Q

What are the Scapulohumeral muscles?

A

Deltoid

Teres major

17
Q

What innervates the Deltoid?

A

The axillary nerve

18
Q

What is the main action of the anterior fibres of the Deltoid?

A

Flex the arm at the shoulder

19
Q

What is the main action of the posterior fibres of the Deltoid?

A

Extend the arm at the shoulder

20
Q

What is the main function of the middle fibres of the Deltoid?

A

Major abductors of the arm, from 15 degrees onwards

21
Q

What innervates Teres major?

A

The lower subscapular nerve

22
Q

What are the main actions of the Teres major?

A

Adductors the shoulder

Medially rotates the arm

23
Q

What are the 4 rotator cuff muscles?

A

Supraspinatus
Infraspinatus
Teres minor
Subscapularis

24
Q

What is main function of the rotator cuff muscles?

A

Add stability to the glenohumeral joint

25
Q

What innervates the Supraspinatus muscles?

A

Suprascapular nerve

26
Q

What is the main action of the Supraspinatus muscle?

A

First 15 degrees abduction of the arm

Aids the Deltoid for the rest

27
Q

What innervates the Infraspinous muscle?

A

Suprascapular nerve

28
Q

What is the main action of the Infraspinous muscle?

A

Lateral rotation of the arm

29
Q

What innervates the Subscapularis muscle?

A

Upper and lower Subscapular nerve

30
Q

What is the main action of the Subscapularis muscle?

A

Medially rotates the arm

31
Q

What innervates Teres minor?

A

The axillary nerve

32
Q

What is the main action of Teres minor?

A

Lateral rotation of the arm

33
Q

What is a sign of rotator cuff tendonitis?

A

Painful arc syndrome

34
Q

What is painful arc syndrome?

A

Pain in the middle of abduction of the arm due to the affected area coming into contact with the acromion

35
Q

What is the pathology of rotator cuff tendonitis?

A

Degenerative changes in the subacromial bursa and supraspinatus tendon due to repetitive use.