the shoulder and proximal upper extremity

Question 1

what are the muscles that compose the anterior part of the shoulder?

Answer 1

• Pectoralis Major
• Deltoid
• Subscapularis
• subclavius
• pectoralis minor
• serratus anterior

Question 2

Pectoralis Major
origin
insertion
action?

Answer 2

origin: medial clavicule and sternal head
insertion: lateral lip of the intertubercular groove of the humerus
action: GH flexion, Adduction and internal rotation

Question 3

Deltoid
origin
insertion
action?

Answer 3

origin: lateral third of the clavicle, acromion and spine of the scapula
insertion: deltoid tuberosity of the humerus
action:
1) anterior fibers: GH flexion and medial rotation
2) middle fibers: GH abduction
3) posterior fibers: GH extension and lateral rotation

Question 4

Subscapularis
origin
insertion
action?

Answer 4

origin: subscapular fossa
insertion: lesser tubercule of the humerus
action: internal rotation of the GH joint

Question 5

subclavius
origin
insertion
action?

Answer 5

origin: costal cartilage of rib I
insertion: inferior surface of clavicle
action: depression of the clavicle

Question 6

pectoralis minor
origin
insertion
action?

Answer 6

origin: ribs 3-5
insertion: coracoid process of the scapula
action: depression of the scapula

Question 7

serratus anterior
origin
insertion
action?

Answer 7

origin: Lateral border of ribs I-VIII
insertion: anteromedial border of the scapula
action: protraction (abduction) and depression of the scapula

Question 8

what anterior shoulder muscles act on the GH joint?

Answer 8

• deltoid
• pectoralis major
• subscapularis

Question 9

what anterior shoulder muscles act on the “scapulothoracic joint”?

Answer 9

• pectoralis minor
• subclavius
• serratus anterior

Question 10

what muscles make up the rotator cuff? do they belong to the anterior or posterior side of the shoulder?

Answer 10

• subscapularis (anterior)
• supraspinatus (posterior)
• infraspinatus (posterior)
• teres minor (posterior)

Question 11

what is the acronym to recall the rotator cuff muscles?

Answer 11

SItS muscles

Question 12

what is the common function shared by the muscles of the rotator cuff?

Answer 12

they create a cuff around the GH joint and stabilize it.

Question 13

what are some joint components found around the subscapularis muscle?

Answer 13

we have 2 different bursaes to relieve frictions

• subtendinous bursa of subscapularis
• subcoracoid bursa to reduce friction between the muscle and the coracoid process which sits rights above

Question 14

Supraspinatis
origin
insertion
action?

Answer 14

origin: supraspinous fossa of the scapula
insertion: greater tubercule of the humerus (superior facet)
action: initiates arm abduction at the GH joint for the first 30 degrees of motion

Question 15

what is the name of the bursa found next to the supraspinatus muscle? why?

Answer 15

-the subacromial bursa prevents the belly of the muscle from being caught in the acromion
there is also lateral to it the subdeltoid bursa.

Question 16

Infraspinatus
origin
insertion
action?

Answer 16

origin: Infraspinous fossa of the spine of the scapula
insertion: greater tubercules of the humerus (middle facet)
action: external rotation of the arm

Question 17

teres minor
origin
insertion
action?

Answer 17

origin: Lateral superior border of the scapula
insertion: greater tubercule of the humerus (inferior facet)
action: external rotation of the arm

Question 18

where is the subacromial bursa located?

Answer 18

right above the tendon of the supraspinatus and below the acromion on the posterior side of the shoulder

Question 19

where is the subcoracoid bursa located?

Answer 19

above the subscapularis muscles and beneath the coracoid process on the anterior side of the shoulder

Question 20

where is the subtendinous burda of subscapularis located?

Answer 20

on the anterior inferior side of the shoulder between the subscapularis muscle and the tendon of the bicep brachii

Question 21

what are the posterior muscles of the shoulder excluding those of the rotator cuffs?

Answer 21

• Teres Major
• levator scapulae
• Rhomboid minor and major
• trapezius
• latissimus dorsi

Question 22

Teres Major
origin
insertion
action?

Answer 22

origin: lateral (inferior) border of the scapula
insertion: medial lip of the interbercular groove on the humerus
action: extension, addiction and internal rotation of the GH joint

Question 23

the greater tubercule is a common insertion to what?

Answer 23

3 of the 4 muscles of the rotator cuff

SIt

Question 24

what is the triangular space bordered by? what does this space contain?

Answer 24

• teres minor
• tricep brachii long head
• teres major

this space contains the curcymflex scapular artery

Question 25

what is the quadrangular space bordered by? what does this space contain?

Answer 25

- teres minor - proximal humerus - Teres major - triceps brachii long head contains: auxillary nerve and posterior circumflex humeral artery

Question 26

Levator Scapulae origin insertion action

Answer 26

origin: TPS CI-CIV insertion: superomedial boarder of the scapula action: elevation and downwards rotation of the scapula

Question 27

Rhomboid minor and major origin insertion action?

Answer 27

origin: SP’s CVII-TV insertion: medial boarder of the scapula action: retraction (Adduction) of the scapula slight contibution to the elevation and downwards rotation of the scapula

Question 28

what type of back muscles are the levator scapulae and the rhomboid minor and major?

Answer 28

they are part of the second superficial layer of the back’s extrinsic muscles

Question 29

``` Trapezius origin insertion action innervation blood supply ```

Answer 29

origin: external occipital protuberance, ligamentum of nuchae, SPs CVII-TXII insertion: spine of the scapula, acromion and clavicle action: upper fibers --> elevate the scapula middle fibers --> retraction (adduction) and upward rotation of the scapula lower fibers --> upwards rotation of the scapula during adduction of the arm during depression of the scapula innervation: spinal accessory nerve C11 blood supply: transverse cervical artery

Question 30

Latissimus Dosi origin insertion action

Answer 30

origin: SPs of TVI-LV, sacrum, illiac crest, throacolumbar apneurosis insertion: floor of the interbercular groove of the humerus action: extension, adduction and internal rotation of the arm at the GH joint.

Question 31

the intertubercular groove is a common insertion for which muscles?

Answer 31

- Pectoralis Major - Latissimus Dorsi - Teres Major

Question 32

what acronym(s) can you use to recall the insertions on the intertubercular groove?

Answer 32

-PLT or -A miss between 2 majors

Question 33

what is the trianglular interval bordered by? what does this space contain?

Answer 33

- Teres Major - long head of the tricep muscle - lateral head of the tricep muscle conains: the deep brachial artery and the radial nerve