Shoulder Region Intrinsic Muscles

Question 1

The intrinsic muscles connect?

Answer 1

Scapula to humerus

Question 2

Name the muscles that connect scapula to humerus?

Answer 2

1. Deltoid
2. Supraspinatus
3. Infraspinatus
4. Teres minor
5. Teres major
6. Subscapularis

Question 3

Name the rotator cuff muscles?

Answer 3

1. Supraspinatus
2. Ifraspinatus
3. Teresminor
4. Subscapularis

Question 4

Rotator cuff muscles attach to which part of shoulder joint?

Answer 4

Capsule

Question 5

Shape of deltoid?

Answer 5

Triangular

Question 6

Parts of deltoid? And origin of deltoid?

Answer 6

1. Clavicular fibres - originates from lateral 3rd of clavicle
2. Acromial fibres - originate from the acromion of scapula
3. Spinal fibres - originate from spine of scapula

Question 7

Insertion of deltoid?

Answer 7

Deltoid Tuberosity on lateral aspect of humerus

Question 8

Nerve supply of deltoid muscle?

Answer 8

Axillary nerve

Question 9

Axillary nerve arises from which part of brachial plexus?

Answer 9

Posterior cord of brachial plexus

Question 10

Vascular supply of deltoid?

Answer 10

1. Thoracoacromial artery
2. Anterior and posterior humeral circumflex artery
3. Subscapular artery
4. Deltoid branch of profunda brachii artery

All arise from axillary artery except profunda brachii which arises from brachial artery

Question 11

Action of deltoid?

Answer 11

Anterior (clavicular) fibres:
Flex and medially rotate the arm

Posterior (spinal) fibres:
Extend and laterally rotate the arm

Acromial (middle) fibres
Abduct the arm (takes over from from supraspinatus which abduct the first 15°)

Question 12

In relation to trapezius, supraspinatous lies?

Answer 12

Deep to it

Question 13

Origin of supraspinatus muscle?
Insertion?

Answer 13

Originates from Supraspinatus fossa of scapula
Runs under acromion
Inserts on the greater tubercle of humerus

Question 14

How many facets of greater tubercle of humerus ?
And which muscles inserts on them?

Answer 14

3 facets:
1. Superior facet - supraspinatus
2. Middle facet - infraspinatus
3. Inferior facet - teres minor

Question 15

Which nerve supplies supraspinatus muscle?

Answer 15

Suprascapular nerve

Question 16

Nerve supply for infraspinatus?

Answer 16

Suprascapular

Question 17

Function of supraspinatus?

Answer 17

Abducts the arm
Stability to shoulder joint

Question 18

Infraspinatus muscle originates from?

Answer 18

Infraspinatus fossa of scapula

Question 19

Action of infraspinatus?

Answer 19

laterally rotates the humerus at glenohumeral joint

Stabilizes shoulder joint

Question 20

Origin of teres minor?

Answer 20

Upper two thirds of the lateral border of scapula

Question 21

Location of teres minor?

Answer 21

Just below infraspinatus
And just above teres major

Question 22

Insertion of teres minor?

Answer 22

Inferior facet of greater tubercle of humerus

Question 23

Function of teres minor?

Answer 23

Same as infraspinatus:
Laterally rotates the arm
Stabilizes the joint

Question 24

Nerve supply of teres minor?

Answer 24

Axillary nerve

Question 25

Axillary nerve supplies which 2 muscles?

Answer 25

Deltoid and teres minor

Question 26

Origin of teres major?

Answer 26

**Lower 3rd** of **lateral border** of scapula

Question 27

Insertion of teres major?

Answer 27

**medial lip** of **intertubercular groove** of humerus

Question 28

Action of teres major?

Answer 28

**Adducts** the arm **Medially** rotates it

Question 29

What function do the lady (latissimus dorsi) and two majors (pectoralis major and teres major) have in common?

Answer 29

Adduct the arm Medially rotate it Extend it

Question 30

Teres major is supplied by which nerve?

Answer 30

Lower subscapular nerve

Question 31

Nerve supply of rotator cuff mucles?

Answer 31

1. Supraspinatus and 2. Infraspinatus --------- **Suprascapular nerve** 3. Teres minor-----**axillary nerve** 4. Subscapularis----**upper and lower subscapular nerve**

Question 32

The lower subscapular nerve originates from which part of brachial plexus?

Answer 32

**posterior** cord of brachial plexus

Question 33

Origin of subscapularis muscle?

Answer 33

Subscapularis fossa of scapula

Question 34

Insertion of subscapularis muscle?

Answer 34

On **lessor tubercle** of humerus

Question 35

Action of subscapularis?

Answer 35

Same as teres major (as have same nerve supply from subscapularis nerve) **Medially** rotate the arm Stabilizes shoulder joint

Question 36

Insertion of rotator cuff muscles is on?

Answer 36

**humerus** 3 on greater tuberosity of humerus 1 on lesser

Question 37

The largest and strongest rotator cuff muscle?

Answer 37

Subscapularis

Question 38

Rotator cuff syndrome? Rotator cuff tendonitis?

Answer 38

Inflammation Injury Degeneration of rotator cuff **Muscle tear/tendinitis** Common in young atletes E.g when bowling in cricket Main affected muscle is **supraspinatus** As it gets pinched underneath acromion

Question 39

What is subacromial impingement syndrome?

Answer 39

Associated with rotator cuff injuries Subacromial impingement syndrome is a condition where the tendons and bursa in the shoulder become compressed and irritated, causing pain, weakness, and limited range of motion in the shoulder. **Supraspinatus Tendonitis** **Subacromial Bursitis**

Question 40

What is bursa?

Answer 40

Fluid filled sac that reduce friction between surfaces

Question 41

Origin of deltoid?

Answer 41

Lateral 3rd of **clavicle** **Acromion** **Spine** of scapula

Question 42

The initial abduction (first 15°) of arm is done by which muscle?

Answer 42

Supraspinatus

Question 43

Which muscle forms the inferior border of quadrangular space?

Answer 43

Teres major

Question 44

What muscle forms superior border of quadrangular space?

Answer 44

Teres minor

Question 45

What is on the lateral side of quadrangular space?

Answer 45

Surgical neck of humeus

Question 46

What is on the medial side of quadrangular space?

Answer 46

Long head of triceps

Question 47

What passes through the quadrangular space?

Answer 47

1. Axillary nerve 2. Posterior humeral circumflex artery

Question 48

What is the basic purpose of rotator cuff muscles?

Answer 48

Pull humeral head into glenoid fossa Additional stability to glenohumeral joint

Question 49

Treatment of rotator cuff tendinitis?

Answer 49

Rest , analgesia (pain relief without losing consciousness by painkillers) Steroid injection or surgery

Question 50

Which harmone is in steroid injection?

Answer 50

Steroid injections contain synthetic versions of the hormone **cortisol**, which is a type of steroid hormone produced by the adrenal gland. Cortisol has anti-inflammatory and immunosuppressive effects, which is why it is used in steroid injections to reduce inflammation and swelling in various parts of the body.