Elbow

Question 1

what determines the height at which the hand will be

Answer 1

shoulder

Question 2

what determines the distance away from the body the hand will be

Answer 2

elbow
-can also influence wrist + hand function

Question 3

how many joints within the elbow joint

Answer 3

2

Question 4

2 joints of the elbow joint

Answer 4

-humeroulnar
-humeroradial

Question 5

humeroulnar + humeroradial joints (elbow joints) function together as what type of joint

Answer 5

hinge joint

Question 6

why are the 2 elbow joints considered a hinge joint

Answer 6

because majority of motion happens in 1 plane
-flexion/extension mostly (sagittal)

Question 7

during elbow flexion, you go from…

Answer 7

abducted to less abducted

Question 8

where is the troachlea located

Answer 8

on humerus

Question 9

where is the troachlear notch

Answer 9

on ulna
-where olecranon runs around front of trochlea

Question 10

where is coronoid fossa located

Answer 10

front of humerus

Question 11

where is olecranon fossa located

Answer 11

back of humerus

Question 12

close-packed position of humeroulnar joint

Answer 12

full extension + supination

Question 13

loose-packed position of humeroulnar joint

Answer 13

70 degrees flexion + 10 degrees supination

Question 14

describe humeroradial joint anatomy

Answer 14

-capitulum is convex
-radial head is concave

Question 15

close-packed position of humeroradial joint

Answer 15

90 degrees flexion + 5 degrees supination

Question 16

loose-packed position of humeroradial joint

Answer 16

full extension + supination

Question 17

close/loose-packed position of humeroradial joint is…

Answer 17

opposite of humeroulnar joint

Question 18

describe joint capsule of elbow joint

Answer 18

encloses humeroulnar, humeroradial, + superior radioulnar joints

Question 19

where is joint capsule of elbow weaker

Answer 19

anterior + posterior
-okay because we have good body stability anteriorly + posteriorly in elbow

Question 20

medial ulnar collateral ligament

Answer 20

-anterior bundle
-posterior bundle
-transverse bundle

when elbow is bent, anterior is on top, transverse on bottom, + posterior goes under transverse

Question 21

describe posterior bundle of medial ulnar collateral ligament

Answer 21

large fan shape
-means it can provide tension + support through large ROM

Question 22

most of support comes from what part of medial ulnar collateral ligament when elbow is EXTENDED

Answer 22

anterior bundle

Question 23

most of support comes from what part of medial ulnar collateral ligament when elbow is FLEXED

Answer 23

posterior bundle

Question 24

lateral ligaments of elbow

Answer 24

-lateral (radial) collateral ligament
-lateral ulnar collateral ligament

when elbow is bent, lateral/radial collateral ligament is on top + lateral ulnar collateral ligament is on bottom; run from HUMERUS to ULNA

Question 25

what is responsible for valgus stresses in 90 degrees of flexion

Answer 25

UCL (ulna collateral ligament) is responsible for >50% of valgus stresses in 90 degrees of flexion -when you flex elbow, you lose bony stability (loose-packed position of humerus/ulna), so you must depend on POSTERIOR part of UCL to stabilize medial elbow

Question 26

what is responsible for valgus stresses in elbow extension

Answer 26

bone, UCL, + capsule all equal responsibility -with elbow extended (close-packed position for humerus/ulna, aka good bony stability), you have anterior band of UCL + capsule all providing good stability to valgus stresses

Question 27

what is responsible for varus stresses in elbow extension

Answer 27

-50% bone -50% LCL ligaments + capsule

Question 28

what stabilizes against varus stresses at 90 degrees of flexion

Answer 28

bone is the main stabilizer

Question 29

ROM of elbow flexion

Answer 29

~145 degrees -amount of flexion depends on amount of soft tissue (biceps, brachialis, etc.) that gets squished between the forearm + humerus -depend on person

Question 30

what limits elbow flexion

Answer 30

amount of soft tissue (biceps, brachialis, etc.) that gets squished between the forearm + humerus

Question 31

ROM of elbow extension

Answer 31

extension to 0 degrees of slight hyperextension -extension is limited by the impact of the olecranon into the olecranon fossa

Question 32

what limits elbow extension

Answer 32

the impact of olecranon into olecranon fossa

Question 33

elbow joint naturally has valgus/varus

Answer 33

valgus -with your arms down by your side, you are actually starting in an extended, abducted position

Question 34

carrying angle

Answer 34

naturally valgus

Question 35

what is valgus configuration of carrying angle determined by

Answer 35

the configuration of articulating surfaces

Question 36

valgus carrying angle is greater in men/women

Answer 36

women -5 degrees in men -10-15 degrees in women

Question 37

carrying angle is measured by what 2 things

Answer 37

-arm in anatomical position -angle formed between long axis of humerus + long axis of forearm