Scapula and Arm muscles, ost, and arth

Question 1

What are the scapular muscles?

Answer 1

• deltoids
• supraspinatus
• infraspinatus
• teres minor
• subscapularis
• teres major

Question 2

What are the attachment points of deltoid?

Answer 2

MA (anterior head): anterior lateral 1/3rd of clavicle
MA (middle head): lateral acromion
MA (posterior head): spine of the scapula
LA: deltoid tuberosity

Question 3

What are the actions of deltoid?

Answer 3

(all heads): G-H abduction
(anterior head): G-H medial rotation, flexion, horizontal adduction
(posterior head): G-H lateral rotation, extension, horizontal abduction

Question 4

Describe the deltopectoral triangle

Answer 4

The divergence of pec major and anterior deltoid form a triangle with the clavicle. It’s where the coracoid process is most palpable. (a.k.a. deltopectoral groove)

Question 5

What’s the clinical relevance of the deltopectoral triangle?

Answer 5

the cephalic vein lies within and this is also the easiest access point when palpating the coracoid process

Question 6

What are the rotator cuff muscles?

Answer 6

SITS

• supraspinatus
• infraspinatus
• teres minor
• subscapularis

Question 7

What are the attachment points of supraspinatus?

Answer 7

MA: supraspinous fossa
LA: superior facet of the greater tubercle of the humerus (also the G-H joint capsule)

Question 8

What are the actions of supraspinatus?

Answer 8

• abduction

- stabilizes the G-H joint by ‘tucking’ the head of the humerus up into the glenoid fossa

Question 9

What are the attachment points of infraspinatus?

Answer 9

MA: infraspinous fossa
LA: middle facet of the greater tubercle of the humerus (also the G-H joint capsule)

Question 10

What are the actions of infraspinatus?

Answer 10

G-H external rotation

Question 11

What are the attachment points of teres minor?

Answer 11

MA: lateral middle border of the scapula (between triceps and teres major)
LA: inferior facet of the greater tubercle of the humerus (also the G-H joint capsule)

Question 12

What are the actions of teres minor?

Answer 12

G-H external rotation

Question 13

What are the attachment points of subscapularis?

Answer 13

MA: supscapular fossa (fills the whole fossa)
LA: lesser tubercle (medial lip of the bicipital groove of the humerus (also the G-H joint capsule))

Question 14

What are the actions of subscapularis?

Answer 14

G-H internal rotation

Question 15

What are the attachment points of teres major?

Answer 15

MA: posterior surface of the inferior angle of the scapula
LA: medial lip of the bicipital groove

Question 16

What are the actions of teres major?

Answer 16

• G-H internal rotation
• G-H extension
• G-H adduction

Question 17

What are the names and location of the bones of the forearm?

Answer 17

• radius: lateral bone in the forearm

- ulna: medial bone in the forearm

Question 18

What are the (5) structures of the anterior view of the radius?

Answer 18

• head
• neck
• radial tuberosity
• interosseous border
• styloid process

Question 19

What are the (2) structures of the pronated view of the radius?

Answer 19

• dorsal tubercle (a.k.a. Lister’s tubercle)

- ulnar notch

Question 20

What are the (9) structures of anterior view of the ulna?

Answer 20

• olecranon
• trochlear notch
• coronoid process (in full flexion fits into coronoid fossa of humerus)
• radial notch
• ulnar tuberosity
• supinator crest
• interosseous border
• styloid process
• head

Question 21

What are the relative locations of heads and notches on the radius and ulna?

Answer 21

• head of radius at proximal end; head of ulna at distal end

- ulnar notch (on radius) at distal end; radial notch (on ulna) at proximal end

Question 22

What are the articulations of the elbow joint?

Answer 22

humeroulnar and humeroradial articulations

Question 23

Describe the humeroulnar articulation

Answer 23

• anteriorly: the trochlea of the humerus articulates with the trochlear notch of the ulna
• posteriorly: the olecranon articulates with the olecranon fossa (in full extension)

Question 24

Describe the humeroradial articulation

Answer 24

the capitulum articulates with the head of the radius

Question 25

What type of joint is the elbow?

Answer 25

synovial hinge (very stable)

Question 26

What are the available movements of the elbow joint?

Answer 26

flexion/extension

Question 27

What are the collateral ligaments of the elbow, what are their attachment point, and what do they prevent?

Answer 27

• lateral (radial) collateral ligament: lateral epicondyle (of the humerus) and annular ligament of the radius; prevent excessive varus deviation
• medial (ulnar) collateral ligament: medial epicondyle and coronoid process, olecranon process; prevents excessive valgus deviation

Question 28

Where is the olecranon bursa? What’s inflammation of this bursa known as?

Answer 28

• between the olecranon and overlying skin

- inflammation known as “students’ elbow”