ELBOW Flashcards
(99 cards)
1
Q
What joints make up the elbow joint?
A
Humeroulnar & Humeroradial
2
Q
What joints make up the elbow complex?
A
Humeroulnar, Humeroradial, PRUJ & DRUJ
3
Q
What type of joint is the elbow joint?
A
Loose hinge
4
Q
How many degrees of freedom does the elbow joint have?
A
1 - flexion/extension
5
Q
What type of joint are PRUJ & DRUJ?
A
Diarthrodial pivot-type
6
Q
How many degrees of freedom do PRUJ & DRUJ have?
A
1 - supination/pronation
7
Q
What is the medially located humeroulnar articulation?
A
Trochlea
8
Q
What does the coronoid fossa receive at the end of elbow flexion?
A
Coronoid process of ulna
9
Q
What is the proximal humeroradial articulation?
A
Capitulum
10
Q
What separates the capitulum from the trochlea?
A
Capitulotrochlear groove
11
Q
What does the radial fossa receive in full elbow flexion?
A
Head of radius
12
Q
What does the olecranon fossa receive in full elbow extension?
A
Olecranon process of ulna
13
Q
What is the distal joint surface of the humeroulnar/humeroradial joint made up of?
A
Radius & ulna
14
Q
What is the concavity on the ulna that contains the trochlear ridge called?
A
Trochlear notch
15
Q
What is the most proximal end of the trochlear notch?
A
Olecranon process
16
Q
What is the more distal end of the trochlear notch?
A
Coronoid process
17
Q
Where is the radial notch located in relation to the coronoid process?
A
Lateral
18
Q
What is the cup-shaped concave surface on the radius called?
A
Fovea
19
Q
What does the convex rim that surrounds the fovea fit into?
A
Capitulotrochlear groove
20
Q
What slides on the trochlea for the humeroulnar joint?
A
Trochlear notch
21
Q
When do the trochlear notch and trochlea not make direct contact?
A
30-120 degrees of flexion
22
Q
Which joints are enclosed by the joint capsule?
A
Humeroulnar, Humeroradial, Superior radioulnar
23
Q
True or False: The joint capsule is large, strong, and continuous with collateral ligaments.
A
False (loose & weak)
24
Q
What lines the coronoid, radial, and olecranon fossa?
A
Synovial membrane
25
Where can the triangular synovial fold be found?
Between proximal radius & ulna
26
What can hypertrophy of the joint capsule cause?
Lateral epicondylalgia, inflammation, or degenerative changes
27
What aggravates hypertrophy of the joint capsule?
Repetitive activities like gripping, wrist extension, push-ups
28
What improves hypertrophy of the joint capsule?
Distraction of humeroradial joint
29
Which bundle of the MCL is the primary restraint to valgus stress during 20-120 degrees of elbow flexion?
Anterior bundle
30
What does the posterior bundle of the MCL limit?
Elbow extension & is less of a restraint to valgus stability
31
Which bundle of the MCL helps keep joint surfaces in approximation?
Transverse bundle
32
Which part of the LCL reinforces the humeroradial articulation?
Lateral radial collateral
33
What do the lateral ulnar collateral ligament and annular ligament provide?
Secondary restraint to combined forced varus & supination stress
34
What are the flexors of the elbow joint?
Brachialis, Biceps brachii, Brachioradialis, FCR, FCU, FDS, PL
35
Which are the main flexors of the elbow joint?
Brachialis, Biceps brachii, Brachioradialis
36
What are the extensors of the elbow joint?
Triceps brachii, Anconeus, ECRL, ECRB, EDC, ECU, EDM
37
Which are the main extensors of the elbow joint?
Triceps brachii, Anconeus
38
What is the normal carrying angle of the elbow?
15 degrees
39
What is considered a valgus carrying angle?
> 15 degrees
40
What is considered a varus carrying angle?
< 5 degrees
41
How many degrees of flexion does the elbow have (AROM & PROM)?
AROM: 135-145, PROM: 150-160
42
True or False: The elbow has more flexion in pronation.
False (supination)
43
For stability during full extension, what contributes 50% from bone?
LCL & capsule of varus stress
44
Where does stability during 90 degrees of flexion come from?
Anterior part of MCL resisting valgus & distraction stress, osseous (mostly), LCL & capsule resisting varus
45
What provides stability during full flexion?
Coronoid process with the fossa & rim of the radial head
46
Which of the three main flexors are mobility muscles?
Brachialis & Biceps
47
What is the other main flexor that is a compressing muscle?
Brachioradialis
48
Where is the moment arm of brachialis greatest?
Slightly more at 100 degrees elbow flexion
49
Where is the moment arm of biceps brachii greatest?
80-100 degrees elbow flexion
50
When is biceps brachii less effective as a flexor?
When in full extension
51
When is biceps brachii most active during elbow flexion? (supination, pronation, neutral)
Forearm supinated
52
Where is the moment arm greatest for brachioradialis?
100-120 degrees elbow flexion
53
True or False: Triceps are unaffected by the position of the forearm but are affected by the shoulder.
True
54
When does triceps have active insufficiency with elbow extension?
When shoulder is hyperextended
55
What does triceps act as a synergist to prevent?
Elbow flexion
56
What five parts make up the PRUJ?
Radial notch of ulna, Annular ligament, Radial head, Radial fovea, Humeral capitulum
57
What three parts make up the DRUJ?
Ulnar notch of radius, Radioulnar disc (triangular fibrocartilage complex), Head of ulna
58
Which ligament of PRUJ encircles the radial head?
Annular ligament
59
What does the quadrate ligament of PRUJ reinforce?
Inferior aspect of joint capsule, maintains radial head to notch, limits spin of radial head in supination & pronation
60
Which ligament of PRUJ has fibers at right angles to fibers of interosseous membrane?
Oblique cord
61
Where do the dorsal & palmar ligaments of DRUJ insert?
Ulnar fovea & base of ulnar styloid
62
When can TFCC & DRUJ capsule provide stability? (Which one limits ROM?)
After injury & scar tissue build up
(DRUJ limits ROM after injury)
63
What stabilizes both PRUJ & DRUJ during rotation?
Interosseous membrane
64
What does pronator teres do?
Stabilizes proximal radioulnar & humeroradial joints and performs pronation & elbow flexion
65
Which radioulnar muscle is a dynamic stabilizer of the distal radioulnar joint?
Pronator quadratus
66
Which radioulnar muscle is an elbow flexor and supinator?
Biceps
67
What is active in all positions and wraps around the radius in pronation?
Supinator
68
What is supination?
(bone alignment?)
When bones are parallel
69
What limits supination?
Tension from palmar radioulnar & oblique cord ligaments
70
When is torque generation greatest with supination/for the supinator muscle?
Forearm in pronation (75%)
71
During pronation, which bone rotates around which?
Radius rotates around ulna
72
What limits pronation?
Bone on bone & tension from dorsal radioulnar & posterior MCL ligaments
73
When is torque generation greatest with pronation?
Forearm in supination
74
What is the ROM of the radioulnar axis of motion (supination/pronation)?
150 degrees
75
In what position is the ROM of the radioulnar axis measured?
Elbow flexion because of shoulder internal/external rotation
76
True or False: Pronator teres is unaffected by changes in elbow flexion/extension.
False (quadratus)
77
Which muscle performs unresisted supination with and without elbow flexion?
Supinator
78
Which muscle performs resisted supination?
Biceps
79
Which muscle can act as a pronator if the forearm is supinated and vice versa?
Brachioradialis
80
When is brachioradialis most active?
Rapid supination/pronation with elbow at 90 degrees
81
What two muscles provide radioulnar stability at the DRUJ?
Pronator quadratus & ECU
82
What muscle stabilizes the forearm in pronation/supination and gripping activities?
ECRB
83
When is the dorsal radioulnar ligament taut?
During pronation
84
When is the palmar radioulnar ligament taut?
During supination
85
How much joint play do the dorsal & palmar radioulnar ligaments allow before full resistance?
~5 mm
86
What structure transmits compression and tension forces and stabilizes carpals?
TFCC
87
What structure does force transmission especially through weight-bearing?
Interosseous ligament
88
What happens with interosseous during weight bearing?
Greater ground reaction force through radial head due to size, interosseous becomes taut, force transferred from radial head to head of ulna
89
What is the functional ROM for elbow flexion?
~100 degrees (30-130)
90
What is the functional ROM for forearm rotation?
~100 degrees, 50 each for supination/pronation
91
What are the six ossification centers and when do they ossify?
Capitulum (1 year), Radial head (3 yrs), Internal/Medial epicondyle (5 yrs), Trochlea (7 yrs), Olecranon (9 yrs), External/Lateral epicondyle (11 yrs)
CRITOE=1,3,5,7,9,11
92
What injury occurs with FOOSH when the elbow is in extension?
Bony compression injury leading to fracture of proximal ulna & anterior dislocation of radial head
93
What is an example of a muscle compression injury?
Repetitive contractions of FCU (compress ulnar nerve)
94
What is nursemaid's elbow?
A distraction injury where the radius is pulled inferiorly from the annular ligament
95
What type of injury occurs with ulnar collateral ligament and medial joint instability?
Varus/valgus injuries
96
What type of injury has one side compressed while the other is distracted?
Varus/valgus
97
What does ulnar collateral ligament instability cause?
Increased carrying angle & radial head compression on capitulum leading to avascular necrosis of capitulum
98
Why is elbow peripheral neuropathy so common?
Superficial position of nerves & repetitive stresses
99
What are some other examples of varus/valgus injuries?
Ulnar neuritis, medial/lateral epicondylitis
