Elbow and Forearm

Question 1

3 bones of the elbow

Answer 1

distal humerus, unla, and radius

Question 2

Joint of the elbow

Answer 2

Humeroulnar joint (elbow proper)
- Concave moving on convex
- Flex/ext

Humeroradial joint
- Concave moving on convex (capitulum)
- Requires muscles to “pull it in”

Radial-ulnar joint (proximal and distal)
- Sup/pro (rotation)
- Move together. If one moves the other also moves.

The joints are enclosed in a loose, weak joint capsule (the superior radioulnar joint is also encased)
- Medial (ulnar) and lateral (radial) collateral ligaments reinforce the sides

Question 3

Carrying angle

Answer 3

The humerus and the forearm create a carrying angle (in the anatomical position)
- 10-12 degrees in men and 13-17 degrees in women
- Increased slightly on the dominant side
- Cubitus valgus - more than normal
- Cubitus varus - too little
* More than 15 degrees=gunstock deformity

Question 4

Movement of the elbow

Answer 4

Flexion and Extension
Supination/Pronation
- Happens at distal and proximal radio-ulnar joint
- In anatomical position the radius and ulna are parallel
* Pronation - radius rolls

Asses at proximal, measure at distal joint

Question 5

ROM of elbow flexion & extension

Answer 5

Expected AROM
- Elbow flexion = 140-150º
- Elbow extension = 0º (up to 10 degrees hyperextension is acceptable)
- If lacking measured in negative
- End feel is soft, watch for muscle bulk

Testing position:
- Pt in supine or seated
- May have to pad upper arm to allow for full extension

Goniometer:
- Axis: over the lateral epicondyle
- Stationary arm: midline of humerus
- Movable arm: lined with radius

Possible substitutions:
- Flexion or extension of the shoulder
- Flexion or extension of wrist

Question 6

Joints of forearm

Answer 6

Proximal radioulnar
- Radial head and capitulumn/radial notch
- Annular ligament, quadrate ligaments, and the oblique cord provide stability

Distal radioulnar
- Ulnar head and ulnar notch
- Articular disc and radioulnar ligaments provide stability

One degree of freedom-supination/pronation or medial and lateral rotation

The interosseous membrane links and provides stability to the two joints
If there is movement at one joint, there will be movement at the other

Question 7

Forearm supination & pronation ROM

Answer 7

Expected AROM
- Supination and pronation - 80º
End Feel: firm but soft, due to the ligamental support

Supination testing position
- Client seated, with shoulder at 0º and elbow at 90º
- Start at neutral (thumb up)
Goniometer:
- Axis: medial aspect of wrist, proximal to the ulnar styloid
- Stationary arm: parallel to the humerus (down instead of up)
- Movable arm: same as stationary arm, follow the wrist

Pronation testing position
- Client position is the same
- Start at neutral
Goniometer:
- Axis: lateral aspect of wrist proximal to the ulnar styloid
- Stationary arm: same (down not up)
- Moveable arm: same

Question 8

Elbow flexion MMT

Answer 8

Primary Muscles-Biceps Brachii, Brachialis, Brachioradialis (all agonists)

Palpation
- For biceps, place forearm in supination, palpate mid belly or at cubital space for tendon
- Palm down: brachialis
- Thumb up: brachioradialis

MMT AG
- Client in sitting, ask to bend elbow with hand supinated
- Resistance applied proximal to wrist
MMT GM
- Client in sitting arm supported on table

Possible substitutions
- Shoulder extension
- Pronation (pronator teres)
- Wrist and finger extensors (make a fist)

Question 9

Elbow flexion muscles

Answer 9

Biceps Brachii
O: long head-supraglenoid tubercle of scapula, short head-coracoid process
I: Long and short head-radial tuberostiy and bicipital aponerousis
N: Musculocutaneous n.

Brachialis (work horse)
O: distal, anterior humerus
I: coronoid process of ulna
N: musculocutaneous n.

Brachioradilais
O: supracondylar ridge of humerus
I: styloid process of radius
N: Radial n.

Question 10

Elbow extension MMT

Answer 10

Muscle: Triceps Brachii

Palpation
- Place patient in supine or on a table
- The long head is beneath the posterior deltoid
- The lateral head (the strongest) is distal to the posterior deltoid
- The medial head is deep, but can be felt in the distal humerus on either side of the common tricpes tendon

MMT
AG (5,4,3): subject in supine, shoulder to 90º flexion and elbow fully flexed
GM (2,1,0): subjected seated with arm on table, shoulder at 90º, elbow fully flexed

Substitutions
- Flex the shoulder
- Quickly flex the elbow to give appearance of ext

Question 11

Muscles for elbow extension

Answer 11

Triceps brachi - long head
O: infraglenoid tubercle of scapula
I: olecranon of ulna
N: radial

Triceps brachi - lateral head (the work horse)
O: lateral and proximal shaft of humerus
I: olecranon process
N: radial

Triceps brachi: medial head
O: distal 2/3 of medial, posterior humerus
I: olecranon process
N: radial

Question 12

Supination MMT

Answer 12

Muscle: supinator; biceps brachii is weaker

Palpation
- Deep muscle, under the common extensors
- Wrist and fingers must be relaxed
- Get under the extensors

MMT
AG: pt is seated with arm at side elbow at 90º, pt is in neutral, try to turn hand down (into pronation)
GM: pt is prone, arm off table, elbow and shoulder at 90º, watch thumb position

Substitution
- Lateral trunk flexion
- Brachioradialis can supinate from a COMPLETELY pronated position
- Lateral rotation of shoulder
** Note the PIN

Question 13

Muscle for supination

Answer 13

Supinator
O: lateral epicondyle of humerus
I: lateral upper 1/3 of radial shaft
N: radial

Weaker supinator is biceps brachii

Question 14

Pronation MMT

Answer 14

Muscles: pronator teres (proximal) and pronator quadratus (distal)

Palpation
- PT: medial surface of the cubital fossa, runs lateral to radius
- PQ: to deep

MMT
Just like supination, but other direction
AG: pt is seated with arm at side elbow at 90º, pt is in neutral, try to turn hand down (into pronation)
GM: pt is prone, arm off table, elbow and shoulder at 90º, watch thumb position

Pronator Teres Syndrome
- Median n
- Not always pronator
- Struther’s ligament
- Bone spur

Question 15

Places of nerve compression

Answer 15

Median
- Cubital tunnel
*Pronator teres
- Forearm - AIN (FPL, FDP2-3, PQ)
- Carpal tunnel

Ulnar
- Ulnar groove
* Tinel’s sign
- Tunnel of Guyon

Radial
- Humerus
- Divides in the forearm
* Superficial and PIN
* Supinator

Question 16

Ligaments of elbow

Answer 16

Medial and lateral collateral ligaments

Question 17

Medial (ulnar) collateral ligaments

Answer 17

Anterior, Posterior and Transverse
The A-MCL is most powerful
Resist Valgus force (abduction)
“Javelin throwers elbow”
- Tear anterior ligament
- Tommy John Surgery

Question 18

Lateral (radial) collateral ligaments

Answer 18

Radial collateral ligament feathers into the annular ligament (stabilizer for the proximal radioulnar joint)
Lateral ulnar collateral ligament
Resist varus force (adduction)
Injury can result in posterior lateral rotary instability

Question 19

Posterolateral rotary instability

Answer 19

Most common instability in the elbow (FOOSH)-axial load, forearm externally rotates
3 stages
1-radial and proximal ulnar sublux posterior and lateral
2-Subluxation will be Posterior and anterior

Question 20

Assessing for PLRI

Answer 20

Lateral Pivot Shift Test
- Arm over head in extension
- Supinate the forearm
- Flex, axial load and decrease supination (repeat)
- Look for dimple or pain
- Almost impossible to do on awake patient

Stand up/Push up Test (table or chair)
- Shoulders abducted on a chair with arms or table
- Elbows flexed
- Push up
- Pain, apprehension, feeling of popping out
- Cover the radial head with your thumb (relocation test)

Question 21

How to assess ligament stability

Answer 21

Valgus stress test
- used to assess the medial or ulnar collateral ligament
- Pt in supine, elbow is in slight flexion, arm supinated
- one hand on lateral aspect of distal humerus, one hand on medial proximal forearm
- push, compare sides

Varus stress test
- assess the lateral or radial collateral ligament
- Pt in same position
- reverse the hands
- compare sides or look for pain

Question 22

Damage to annular ligament

Answer 22

Referred to as “pulled elbow syndrome” or “Nursemaid’s Elbow”
- Common in Children

Question 23

Elbow capsule during flexion

Answer 23

The anterior capsule is slack
Posterior capsule is taut
Trochlear notch rolls on the convex trochlea
Extensor muscles fully elongate (if not you have passive insufficiency)
Posterior and medial fibers of the medial collateral ligament elongate and are taut
Ulnar nerve elongates (excessive stretch)

Question 24

Elbow capsule during extension

Answer 24

The posterior capsule is slack
The anterior capsule is taut
Anterior fibers of the medial collateral ligament elongate and are taut
Anterior skin is taut
Flexor muscles elongate
The olecranon process slides into the olecranon fossa
- Excessive can result in bone spurs or osteophyte

Question 25

Interosseous membrane

Answer 25

Distributes weight from the radius to the ulna
Protects the wrist and elbow complexes during distraction (oblique cord and annular ligament, BR)

Question 26

If the proximal radioulnar joint moves…

Answer 26

The distal radioulnar joint over rotates
- May result in injury to the
* Distal radiocarpal ligament (DRCL)
* Distal intercarpal ligament (DIL)

Question 27

The proximal radioulnar joint is stabilized by

Answer 27

TFCC (group of ligaments that separates the DRUJ from the radiocarpal joint)
Pronator quadratrus
ECU
DOB

Question 28

Limits in supination and pronation

Answer 28

First make sure it’s Pronation/Supination, not IR or ER

Pronation
- Tight biceps or supinator muscle
- TFCC injury

Supination
- Pronator teres
- Pronator quadratus
- TFCC

Question 29

Biceps brachii reflex special test

Answer 29

Biceps Brachii Reflex
- C5 nerve root test
Place subject forearm over yours with elbow flexed, have them look away
Place your thumb over the biceps brachii tendon, depress slightly
Hit your thumb with the triangular end of the hammer
Normal response-a flexion response
- None: pathological problems at C5
- Too much: upper motor neuron lesion

Question 30

Tinel’s sign

Answer 30

Assesses ulnar nerve in the ulnar groove between the olecronon process and medial epicondyle (funny bone)
Tap with tip of finger
Positive: tingling or electric shock to the ulnar distribution

Question 31

Pinch grip test

Answer 31

Assess the anterior interosseous nerve (branch of the median) as it passes between the two heads of the pronator teres (high pronator teres syndrome)
Ask the patient to tip pinch, index to thumb
If they can only do pad to pad, it is positive (OK sign)

Question 32

Low pronator teres test

Answer 32

Access the median nerve as it passes between two heads
Subject is seated with elbow at 90 degrees, examiner vigorously resists pronation, while elbow is extended
Positive: symptoms along the median nerve distribution

Question 33

Elbow flexion special test

Answer 33

To determine cubital tunnel syndrome (ulnar nerve trapped between the two heads of the flexor carpi ulnaris)
Ask the client to sit, flex the elbow in extreme for 5 minutes
Positive: if you get tingling or parasthesia along the ulnar nerve distribution