elbow/ radio ulnar joints

Question 1

elbow basics (4 including ROM)

Answer 1

1. compound joint which includes humerus, ulnar and radius
2. uniaxial hinge joint
3. moves in x-axis
4. normal ROM 140-150/0 flex/extend
   for charts 0-145 (if hyperextension 10-0-140)

Question 2

anatomy/ movements of elbow joint
2- going into flex
2- flexion
1- extension

Answer 2

going into flexion:
1. trochlear ridge of ulnar slides in trochlear groove of humerus
2. rim of radial head slides in capitula-trochlea groove
(trochlea =medial condyle of H, capitulum = lat condyle of H)
in flexion:
3. coranoid process of U approximates with coranoid fossa of H
4. rim of radial head approximates with radial fossa (U)
in extension (closed packed):
5. olecranon process of U approximates with olecranon fossa of humerus

Question 3

ligaments of elbow (2)

Answer 3

1. medial collateral ligament = ulnar collateral

2. lateral collateral = radial collateral

Question 4

carrying angle

Answer 4

cubital valgus= 10-15deg lateral angle of radius and ulna

when flex move back to midline

Question 5

radial/ ulnar joint (5 including rom)

Answer 5

1. really 2 joints/ proximal and distal
2. uniaxial pivot joints (around Y)
   during pronation/ supination
3. proximal: rim of radial head moves in radial notch on ulnar
4. distal: radius has ulnar/ sigmoid notch and moves over ulnar head
5. normal ROM= 80-90deg pronation/supination

Question 6

ligaments of radial ulnar joint (5- 3 prox/2 distal)

Answer 6

proximal (these stabilize radial head in ulnar notch)
1. annular
2. quadrate
3. oblique
distal:
 4. anterior/posterior ulnar ligament
 5. interosseos membrane

Question 7

radial/ ulnar function (2)

Answer 7

1. hand-wrist orientation

2. ADL’s (keys, tools)

Question 8

elbow flexors (4)

Answer 8

1. biceps
2. brachialis
3. brachioradialis
4. pronator teres

Question 9

elbow extensors (2)

Answer 9

1. triceps

2. aconeous

Question 10

brachialis (2)

Answer 10

1. main flexor/ work horse of the arm

2. palpable on either side of distal bicep tendon

Question 11

bicep (3)

Answer 11

1. 2 joint muscle, crosses elbow and shoulder (flexes shoulder and elbow)
2. active insufficiency = flexion of elbow and shoulder
3. more active with supinated forearm (which is why chin ups are easier than pull ups)

Question 12

brachioradialis (2)

Answer 12

1. flexor/ shunt muscle
2. palpable when elbow is flexed and forearm neutral
   (great drinking muscle)

Question 13

pronator teres (2)

Answer 13

1. shape and location make it a good pronator

2. because crosses elbow it is an flexor

Question 14

wrist muscles that contribute to flexion (5)

Answer 14

1. FCU
2. FCR
3. PL
4. ECRL
5. ECRB

Question 15

triceps (3)

Answer 15

1. primary elbow extensor and extends shoulder
2. mmt (manual muscle test)- lie prone and do horizontal adduction and push against
3. shoulder/ elbow extension = active insufficienty

Question 16

aconeous

Answer 16

1. during complete extension it moves ulnar (posterior attachment) into joint capsule (so not pinched)

Question 17

forearm pronators (2)

Answer 17

1. pronator quadratus 1’ pronator- (not affected by elbow position)
2. pronator teres 2’ pronator- crosses elbow

Question 18

forearm supinators (2)

Answer 18

1. biceps
2. supinator
   in full extension bicep is knocked out so can test supinator

Question 19

elbow/ forearm synergies (2)

Answer 19

1. bicep, pronator teres with tricep
   (tricep stabilized elbow while bicep and pronator teres do pronation)
2. when bicep does elbow flexion posterior deltoid contracts to prevent shoulder flex

Question 20

strength of pronation vs supination

Answer 20

1. supinators stronger (why its easier to tighten a screw and hard to loosen)