Elbow Complex Biomechanics Flashcards Preview

PT 506 Kinesiology > Elbow Complex Biomechanics > Flashcards

Flashcards in Elbow Complex Biomechanics Deck (36):
1

Proximal Radioulnar Joint

Head of radius in radial notch of ulna

2

Distal Radioulnar Joint

Head of ulna in ulnar notch of radius; TFC is articular disc

3

Proximal Elbow complex

Hinge joint, uniaxial diarthrodial, 1 DF

4

Superior and Inferior RU joint

Pivot Joint, uniaxial diarthrodial, 1 DF

5

Elbow joint capsule

Large, lose, weak anterior and posterior
Cross contamination of infections possible at 3 joints

6

MCL

Anterior, Posterior, and Oblique bands
Anterior protects valgus best at 20-120 flexion
Oblique helps ulnar nn and anchors ant/post bands

7

LCL

Resists varus and distractive forces
Weaker than medial

8

Annular Ligament

Stabilizes head of radius to ulna
Very strong

9

Interosseous membrane

Fibers in all directions for strength

10

Humeroulnar joint kinematics

Concave on convex
Same glides and rolls

11

Humeroradial joint kinematics

Concave on convex
Same glides and rolls

12

Proximal Radioulnar joint Kinematics

Radial Head longer A-P when supinated
Radial Head longer M-L when pronated
Spins on capitulum in relation to radial groove

13

Distal Radioulnar joint Kinematics

Concave radius on convex ulna
Anterior roll and glide pronation
Posterior roll and glide supination

14

Axis of motion at elbow

Carrying angle
5-15 Degrees
Cubital valgus when >15
Cubital Varus when <5

15

Carrying angle disappears when...

Pronation combines with full elbow extension/flexion
Due to position of the lever

16

Open Pack position

Joint capsule and ligaments have greatest laxity
Greatest amount of accessory mobility present

17

Closed Pack position

Joint capsule and ligaments are most taut
Most often position of greatest joint congruency

18

Extension ROM

0 degrees normal
May have 5-10 degrees
Hard end feel
Humeroulnar closed pack
Humeroradial open pack

19

Flexion ROM

135-145 AROM
150-160 PROM
Soft/Hard endfeel
Humeroulnar joint closed pack at 70 degrees
Humeroradial joint closed pack at 90 degrees

20

Active Insufficiency

Agonist muscles too short or too long to produce effective tension

21

Passive insufficiency

Antagonist Muscle is on stretch and is too short to allow further passive ROM

22

Spurt Muscle

Mobility muscle
Increased rotary component and angle of pull
Proximal insertion

23

Shunt Muscle

Decreased rotary component, decreased angle of pull
Increased compressive force
Distal insertion

24

Biceps

Spurt muscle
MA greatest between 80-100

25

Brachioradialis

Shunt muscle
MA greatest between 100-110

26

Brachialis

Spurt muscle
MA greatest at 100
Work horse muscle

27

Triceps

Medial head is work horse
Synergistically w/ biceps during resistive forearm supinatoin

28

Anconeus

Initiates elbow extension
Active w/ forced finger flexion and extension
Draws capsule out to prevent impingement

29

Pronation ROM

85 degrees

30

Supination ROM

90 degrees

31

Proximal RU joint open pack position

35 supination, 70 elbow flexion

32

Proximal RU joint closed pack position

5 supination, extension
good for stabilization

33

Lateral Epicondylitis

Repetitive use, primarily ECRB
Tensile stress leads to microtears

34

Medial Epicondylitis

Repetitive use, primarily pronater teres, FCR, FCU

35

Nursemaids elbow

Longitudinal traction force
Radial head extracted from annular ligament then pinches it

36

Medial Collateral Ligament Sprain

Increased tensile stress leads to increased carrying angle
Increased compression of radial head on capitulum
Avascular necrosis when prolonged