Lecture 6: Elbow Flashcards

1
Q

What are the articulating surfaces on the anterior aspect of the distal humerus?

A

Trochlea and capitulum

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2
Q

the trochlea forms part of the ______________ articulation

A

humeroulnar

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3
Q

What portion of the trochlea projects more distally, the medial or lateral?

A

medial

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4
Q

the capitulum is part of the ___________ articulation

A

humeroradial

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5
Q

What does the capitulotrochlear groove separate?

A

The capitulum and the trochlear

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6
Q

The olecranon fossa articulates with the _____ and is on the _________ side of the distal humerus

A

ulna

posterior

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7
Q

What is the radial fossa meant to do?

A

receive the head of the radius during elbow flexion

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8
Q

What articulates with the trochlear groove of the humerus?

A

the trochlear notch and trochlear ridge of ulna

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9
Q

Which process is more distal, the olecranon or coronoid?

A

Coronoid

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10
Q

During flexion, the ulna ________ process slides to the ________ fossa. In extension the ________ slides to the __________ fossa.

A

coronoid
coronoid
olecranon
olecranon

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11
Q

When is the trochlea fully congruent?

A

When loaded

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12
Q

The head of the radius has a _______ fovea that articulates with a _______ capitulum in flexion and extension

A

concave

convex

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13
Q

In humeroradial extension, there is no _______ made between the radial head and the capitulum

A

contact

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14
Q

The “elbow” joint is made up of what three joints?

A

Humeroradial
Humeroulnar
superior radioulnar

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15
Q

The elbow is enclosed in a large, loose capsule that is relatively weak in what direction?

A

anterior/posterior

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16
Q

The capsule of the elbow joint us more stable medially and laterally. Why?

A

It blends with the annular ligament, MCL and LCL

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17
Q

The medial collateral ligament is on what side of the elbow, radial or ulnar?

A

Ulnar

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18
Q

What does the MCL do? 4 main jobs

A

Resists valgus stress at the elbow such as throwing or golfing
Limits extension at the end of the elbow extension
guides jt through flexion ROM
provides resistance to longitudinal distraction of the elbow

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19
Q

The MCL is divided into 3 bundles– what are they?

A

Anterior, posterior, and oblique

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20
Q

What does the anterior bundle of the MCL do?

A

Primarily restrain of valgus stress at 20-120 degrees

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21
Q

What does the posterior bundle of the MCL do?

A

restrain of valgus stress in elbow extension by keeping jt surfaces in approximation

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22
Q

What does the oblique bundle of the MCL do?

A

may be effective in resisting valgus stress and more in joint approximation

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23
Q

Injury to the MCL occurs most frequently during what activity?

A

the backswing portion of pitching, with the shoulder in ER and the elbow flexed

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24
Q

What muscles cover the MCL?

A

FDS, PT, FCU

25
Q

What does the Annular Ligament do?

A

Encircles the radial head

26
Q

What ligament is fan shaped from the lateral epicondyle to the annular ligament and olecranon that reinforces the humeroradial joint and provides primary resistance to varus stress and to joint distraction?

A

LCL

27
Q

What ligament runs from the lateral epicondyle to the ulna and assists LCL in resisting varus stress and adds humeral ulnar stability; close to suprinator, extensor, and anconeus

A

LUCL

28
Q

What muscle is the primary flexor of the forearm?

A

Brachialis

29
Q

The wrist and hand extensors originate on the ________ side of the arm on the _______ epicondyle

A

posterior

lateral

30
Q

The wrist and hand flexors originate on the ________ side of the arm on the _______ epicondyle

A

anterior

medial

31
Q

The carrying angle is typically ____ - ____ degrees and typically decreases with what movement?

A

8-15

pronation

32
Q

The major flexors of the elbow are:

A

biceps brachii
Brachialis
Brachioradialis

33
Q

The major extensors of the elbow are:

A

triceps

anconeus

34
Q

When us the humerolunar joint in a close-packed position?

A

In full extension

35
Q

How much flexion does the elbow have both AROM and PROM?

A

AROM: 135-145
PROM: 150-160

36
Q

How does the forearm and shoulder position affect the brachialis muscle action?

A

It doesn’t! It is a one joint muscle from the humerus to the ulna.

37
Q

In what position do you test the brachialis muscle?

A

Pronation resisting supination

38
Q

What muscle helps with supination of the forearm but is affected by the position of the forearm and shoulder?

A

Biceps bracii

39
Q

What elbow flexor is considered a “stability” muscle due to its distal attachment far from the joint?

A

brachioradialis

40
Q

What are the two jobs of the anconeus?

A

Elbow extension

stabilizing during pronation/supination

41
Q

Is the triceps affected by forearm position?

A

No

42
Q

When is the moment arm of the triceps the best?

A

at 90 degrees

43
Q

What head of the triceps can become actively insufficient based on shoulder position?

A

Long head

44
Q

What head of the triceps is active in unresisted extension?

A

Medial head

45
Q

What muscle controls the elbow in the closed kinematic chain?

A

Triceps

46
Q

Name two closed chain activities of the elbow:

A

Pull ups: brachialis (eccentric lowering and concentric pulling up)

Push ups (concentric pushing up and eccentric lowering)

47
Q

What are the articulating surfaces of the superior/proximal radioulnar joint?

A

ulnar radial notch
annular ligament
capitulum
radial head

48
Q

What are the articulating surfaces of the inferior/distal radioulnar joint?

A

ulnar notch of the radius
articular disc (part of TFCC)
ulnar head

49
Q

Both the proximal and distal ends of the TFCC are shaped how?

A

Concavely

50
Q

What does the TFCC do?

A

Provides stability

51
Q

Why is the TFCC considered to be a pain producer?

A

Highly vascular peripherally

52
Q

The proximal and distal radioulnar joints are linked mechanically, this means that they move ________.

A

Together

53
Q

What ligaments are at the proximal radioulnar joint?

A

annular
quadrate
oblique cord

54
Q

What is the purpose of the quadrate ligament?

A

anchors the ulna to the radial neck

Limits the spin of the radius in pronation and supination

55
Q

What does the oblique cord do?

A

Holds the radius and ulna together

56
Q

What radioulnar ligament is at the distal joint?

A

Interosseous membrane

57
Q

What is the function fo the interosseous membrane?

A

keeps radius and ulna aligned AND transfers forces from radius to the ulna

58
Q

Why is the central band of the interosseous membrane high in tensile strength?

A

It is composed of high collagen and it is thick and strong

59
Q

Where are the dorsal and palmar radioulnar ligaments taut, respectively?

A

pronation and supination