Joints

Question 1

what are the 3 joints that make up the elbow?

Answer 1

1. humeroradial joint
2. humeroulnar joint
3. radioulnar joint

Question 2

what is the articulation of the humeroradial joint?

Answer 2

capitulum of humerus + head of radius

Question 3

what are the degrees of freedom (movement) of the humeroradial joint?

Answer 3

flexion, extension, pronation, supination

Question 4

what ligament attaches the humeroradial joint?

Answer 4

radial collateral ligament

Question 5

description of radial collateral ligament?

what happens if it is torn?

Answer 5

fan like, strong
extends from lateral epicondyle of humerus

if torn: arm adducts uncontrollably
tennis elbow: inflammation of this ligament

Question 6

what is the articulation of the humeroulnar joint?

Answer 6

trochlea of the humerus and the trochlear notch of the ulna

Question 7

what are the degrees of freedom (movement) of the humeroulnar joint?

Answer 7

flexion + extension

Question 8

what ligament attaches the humeroulnar joint?

Answer 8

medial ulnar collateral ligament

Question 9

description of medial ulnar ligament?

what happens if it is torn?

Answer 9

has 3 bands:

1. anterior cord-like band (strongest)
2. posterior fan-like band (weakest)
3. oblique band

if torn: abnormal abduction

Question 10

what is the articulation of the radioulnar joint?

Answer 10

head of radius, radial notch of ulna

Question 11

what are the degrees of freedom (movement) of the radioulnar joint?

Answer 11

pronation + supination

Question 12

what ligaments attach the radioulnar joint?

Answer 12

1. anular ligament

2. oblique cord of interosseus membrane

Question 13

how is the anular liigament injured?

Answer 13

pulled elbow: head of radius escaped from this lig.

Occurs mostly in children bc lig isn’t fully developed

Question 14

how stable is the elbow joint?

how is it usually damaged in adults?

Answer 14

Very stable + strong, dislocation usually due to fractures

Fracturing olecranon affects trochlear notch + elbow joint

Question 15

what is the articulation of the AC joint?

what is the articulation covered by?

Answer 15

acromium process of the arcomion and the acromial end of the clavicle

articulating surfaces are covered by fibrocartilage and are separated by wedge-shaped articular disc

Question 16

what is the degrees of freedom (movement) of the AC joint?

Answer 16

sliding and accomodatory movements from articulation of clavicle with sternum + movement of scalpula

Question 17

what are the ligaments of the AC joint?

Answer 17

1. acromiclavicular ligament

2. coracoclavicular ligament (trapezoid + coracoid separated by bursa)

Question 18

what occurs when acromioclavicular ligament is damaged?

what is an example of this?

Answer 18

acromioclavicular subluxation aka shoulder separation: damage to this lig during downward displacement of the clavicle

ex: high school football player tackling with shoulder

Question 19

What is the articulation of the glenohumeral joint?

Answer 19

glenoid foss or glenoid cavity of scapula and head of humerus

Question 20

what are the degrees of freedom (movement) of the glenohumeral joint?

Answer 20

external + internal rotation, flexion + extension, adduction + abduction

lots of movement making it unstable

Question 21

what is a carrying angle?

Answer 21

angle of fully extended ulna with long axis of humerus

more pronounced in women to clear hips

Question 22

what is the nerve supply to the elbow?

Answer 22

musculocutaneous, radial + ulnar nerve

Question 23

what are the bursae of the elbow?

Answer 23

1. Intratendinous olecranon bursae (in tendon of triceps)
2. subtendinous olecranon bursae
3. subcutaneous olecranon bursae
4. non olecranon: bicipitoradial bursae

Question 24

what are the muscles of the elbow?

Answer 24

brachialis
biceps brachii
triceps brachii

Question 25

what kind of joint is the elbow?

Answer 25

synovial joint

Question 26

What type of joint is the AC joint?

Answer 26

plane joint

Question 27

what is the nerve supply of the AC joint?

Answer 27

lateral pectoral and axillary nerves

also cutaneous lateral supraclavicular nerve

Question 28

what kind of joint is the glenohumeral joint?

Answer 28

ball and socket synovial joint

Question 29

what covers the glenohumeral joint?

Answer 29

hyaline cartilage1

Question 30

what muscles surround this joint?

Answer 30

rotator cuff muscles…

1) Supraspinatus
2) Infraspinatus
3) teres minor
4) subscapularis

biceps brachii weakly

hold head of humerus in scapula

Question 31

what ligaments hold the glenohumeral joint together?

Answer 31

1. Glenohumeral Ligaments
2. Coracohumeral Ligament
3. Transverse Humeral Ligament
4. coracoacromial arch

Question 32

what are the muscles of the glenohumeral joint?

Answer 32

scapulohumeral muscles

Axio appendicular muscles act indirectly

Question 33

what is the innervation of the glenohumeral joint?

Answer 33

Suprascapular, axillary and lateral pectoral nerves

Question 34

what is the bursae of the glenohumeral joint?

Answer 34

1. Subtendinous Bursa of Subscapularis (protects subscalpularis tendon)
2. Subacromial Bursa (helps supraspinatus tendon move)

Question 35

How does injury to SITS muscles occur?

Answer 35

often happens to pitchers, head of humerus pops out

Question 36

how does subacromial bursitis occur?

Answer 36

calcium deposits

normally found alongside supraspinatus tendonitis

Question 37

what are the ways the shoulder can become dislocated?

what are the complications?

Answer 37

1. anterior dislocation: head of humerus pops out inferior to coracoid process
   • Complications: axillary nerve ruptured, affecting deltoid + teres minor. Wont be able to abduct arm fully (only 15 degrees).
2. posterior dislocation: Very rare
   • Complications: none bc no nerves