Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biomechanics & Kinematics > Elbow Complex > Flashcards

Elbow Complex Flashcards

1
Q

What anatomy makes up the humeroulnar joint?

A

Humerus
Trochlea
Trochlea Groove
Coronoid fossa
Olecranon fossa
Capitulum
Ulna
Olecranon Process → has a bursa
Coronoid Process
Trochlear notch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what anatomy makes up the humeroradial joint?

A

Humerus
Capitulum
Radial fossa
Radius
Radial head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what anatomy makes up proximal radioulnar joint?

A

Radius
Radial head
Ulna
Radial notch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what anatomy makes up the distal radioulnar joint?

A

Radius
Ulnar notch
Ulna
Head of ulna
Articular Disc (TFC)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what kind of joints are the humeroulnar & humeroradial?

A

hinge joint
uniaxial diarthrodial w/ 1 DF (flex/ext)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what kind of joints are the superior & inferior radioulnar?

A

Pivot joint (trochlear joint), uniaxial diarthrodial with 1 DF (pronation/supination)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the problem with the joint capsule?

A

Bathed in common synovial fluid
Potential for cross contamination of pathology → can bathe all 3 joints at once spreading infection easily

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the Joint Capsule

A

Fairly large, loose, & weak anteriorly & posteriorly
Sides reinforced by ligaments
Encloses all 3 proximal joints

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 4 ligaments of the elbow?

A

Medial Collateral
Lateral Collateral
Annular Ligament
Interosseous Membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does the anterior head of the medial collateral ligament do?

A

Valgus stress stabilizer
Protects best 20-120 degrees flexion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what does the posterior head of the medial collateral ligament do?

A

Less significant than anterior in valgus stability
Co 1 DF valgus restraint at 120 degrees
2 DF at 30 & 90 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what does the oblique head of the medial collateral ligament do?

A

Helps maintain joint surface
Like tape that holds down anterior & posterior fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what does the lateral collateral ligament do?

A

Resists varus stress
Resists distractive (tension) forces of joint surfaces
Weaker than medial collateral ligament

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what does the annular ligament do?

A

Stabilizes head of radius to ulna
Very strong

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

why does the annular ligament have reduced congruency?

A

the annular ligament is circular and the radius is a football shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are the osteokinematic & arthrokinematics of the humeroulnar joint?

A

Osteokinematics: Flexion & Extension
Arthrokinematics: concave on convex (open chain)
Convex on concave (closed chain)
Flexion: anterior roll, anterior glide
Extension: posterior roll, posterior glide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the osteokinematic & arthrokinematics of the humeroradial joint?

A

Osteokinematic: Flexion & Extension
Arthrokinematic: concave on convex
Flexion: anterior roll, anterior slide
Extension: posterior roll, posterior slide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are the osteokinematics & arthrokinematics of the proximal radioulnar joint?

A

osteokinematics : pronation & supination
Radial head is longer A-P supinated
Radial head is longer M-L pronated
Radial head spins on capitulum in relation to radial groove on ulna

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are the osteokinematics & arthrokinematics of the distal radioulnar joint?

A

Osteokinematics: pronation & supination
Concave radius on convex ulna
Pronation: anterior (palmar) roll & glide
Supination: posterior (dorsal) roll & glide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is a carrying angle?

A

Axis of the elbow ROM makes the carrying angle
Measured long axis of humerus & forearm (ulna b/c fixed)
Disappears with pronation & supination combined with full elbow extension as well as full elbow flexion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are the normal degree for carrying angle?

A

5 degrees men
15 degrees women

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is the open pack position?

A

Termed resting position
Position which the joint capsule & ligaments have the greatest laxity
Greatest amount of accessory mobility present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is the closed pack position?

A

Position in which the joint capsule & ligaments are the most taut
Most often it is a position of greatest joint congruency as well but not always

24
Q

what are some check reins to extension?

A

olecranon/olecranon fossa (not a good one b/c bone on bone)
Anterior capsule & anterior portion of collateral ligament tension
Flexor muscle tension

25
Q

when is the humeroulnar joint in closed pack & humeroradial joint in open pack?

A

at terminal extension

26
Q

when is the humeroradial joint in closed pack position?

A

90 degrees flexion

27
Q

what are flexion check reins?

A

Approximation of anterior musculature
Supination → greater flexion range b/c levers of forearm parallel
Pronation → radius over ulnar, increase bony surfaces
Bony articulation
Passive stretch of triceps & posterior capsule

28
Q

what are the primary movers into flexion?

A

Biceps brachii, Brachioradialis, Brachialis

29
Q

what are the secondary movers into flexion?

A

Pronator Teres, wrist flexors (b/c they cross elbow joint)

30
Q

what determines the role of flexor muscles?

A

Location of muscles
Joint ROM
Forearm position
Magnitude of load applied
Type of muscular contraction
Velocity of movement

31
Q

what is active insufficiency?

A

Agonist muscle is too short or too long to produce “effective” & “efficient” tension so no further ROM can be achieved actively
Actin & myosin are either too far apart or too close together

32
Q

what is passive insufficiency?

A

Antagonist muscle is on stretch & is too short (too elongated) to allow further passive ROM

33
Q

is the biceps brachii a spurt or shunt muscle?

A

Spurt Muscle = Mobility Muscle → really creates movement
Increased rotary component, increased angle of pull
Insertion close to axis of elbow joint

34
Q

when is the MA best for the biceps brachii?

A

MA greatest between 80 & 100 flexion

35
Q

why is the biceps not very effective in terminal extension?

A

Not good b/c small angle of pull, small MA & rotatory component

36
Q

when is the biceps brachii most active?

A

Most active w/ forearm supinated & for power activities, both concentric & eccentric → line of pull is best, fiber orientation is best here

37
Q

is brachioradialis a shunt or spurt muscle?

A

Shunt Muscle = Stabilizing Muscle
Decreased rotatory component, decreased angle of pull (lays flat)
Increased compressive force → pulls distal closer to proximal (provides good pivot point)
Insertion far from joint axis

38
Q

when is MA greatest for brachioradialis?

A

MA greates between 100 & 110 degrees flexion → picks up where biceps leaves off

39
Q

when is the brachioradialis most effective?

A

Most effective with forearm 1) Neutral Position (palm facing side/thumb points forward) 2) Full Pronation (b/c fiber orientation muscle laying on top, closer to optional position)

40
Q

is brachialis a spurt or shunt muscle?

A

Spurt Muscle
Insertion close to axis of elbow joint at ulna
Forearm position Brachialis most efficient → all of them

41
Q

when is the MA best for brachialis?

A

MA greatest at approximately 100° flexion
Increased rotatory component, improved length/tension relationship

42
Q

why is the brachialis considered the work horse muscle?

A

Effective in all forearm positions, all contraction types, all speed
Can be isolated in pronated b/c biceps in worst & brachioradialis in 2nd worst potion

43
Q

which head of the triceps is considered the work horse?

A

Medial head is work horse → always active and resisted elbow extension

44
Q

why are we able to screw a screwdriver without our arm flexing?

A

Triceps acts synergistically with biceps during resistive forearm supination

45
Q

describe the Anconeous muscle?

A

Lateral epicondyle to olecranon process
Initiated elbow extension
Has attachment to posterior capsule (will eccentrically contract to keep from getting pinched) & annular ligament
Active with forced finger flexion & extension

46
Q

what are the normal degrees of pronation, supination & neutral?

A

85° pronation: palm facing posterior (inferior)
90° supination: palm facing anterior (superior)
Neutral position: palm faces medially w/ thumb pointed anterior (superior)

47
Q

what are the check reins to pronation?

A

radius over ulna, posterior fibers of medial collateral ligament, posterior radioulnar ligament, supinator muscle

48
Q

what are the check reins to supination?

A

anterior radioulnar ligament, oblique cord, pronator teres, pronator quadratus, interosseous membrane, annular ligament

49
Q

what is the open pack position for proximal radioulnar joint?

A

Open pack positon
35° supination, 70° elbow flexion
Good position to joint play

50
Q

what is the closed pack position for the proximal radioulnar joint?

A

Closed pack positon
5° supination, elbow extended
Good position for promoting stability

51
Q

what is the open & closed pack of distal radioulnar joint?

A

Open pack 10° supination
Closed pack 5° supination

52
Q

what two muscles create supination?

A

Biceps Brachii
Active when resistance is met & with increased speed
Supinator
Acts by unwinding: pulls shaft & distal end of radius off the ulna

53
Q

how does the synergistic relationship work for supination?

A
  • Supinator & Biceps Brachii work synergistically w/ forceful supination at 90° elbow flexion
  • Anconeous & to lesser extend the triceps contracts isometrically to stabilize the ulna
  • Synergist of flexor & extensor to produce supination
54
Q

what muscles create pronation?

A

Pronator Quadratus
Active with & w/o resistance and fast and slow speeds
Pronator Teres → Secondary elbow flexor

55
Q

what is lateral epicondylitis?

A

Repetitive use, contractions primarily of extensor carpi radialis brevis
Tensile stress leading to microtears leading to inflammatory cascade

56
Q

what is medial epicondylitis?

A

Repetitive use primarily of pronator teres, flexor carpi radialis, & sometimes flexor carpi ulnaris

57
Q

what is nursemaid’s elbow?

A

Longitudinal traction (tensile) force
Radial head extraction from annular ligament

Biomechanics & Kinematics (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions