Elbow

Question 1

Humeroulnar Close Packed

Answer 1

Elbow: full extension
Forearm: supinated

Question 2

Humeroulnar Resting

Answer 2

Elbow: 70 deg flexion
Forearm: 10 deg supination

Question 3

Humeroulnar and Radiohumeral Capsular Pattern

Answer 3

Flexion more limited than extension

Rotations full range and painless

Question 4

Radiohumeral Close Packed

Answer 4

Elbow: 90 deg flexion
Forearm: 5 deg supination

Question 5

Radiohumeral Resting

Answer 5

Elbow: 70 deg flexion
Forearm: 10 deg supination

Question 6

Proximal R/U Close Packed

Answer 6

Elbow: N/A
Forearm: 5 deg supination

Question 7

Proximal R/U Resting

Answer 7

Elbow: 70 deg flexion
Forearm: 35 deg supination

Question 8

Superior R/U Capsular Pattern

Answer 8

Equal limitation of pronation and supination

Question 9

Normal ROM for Flex/Ext, Pro/Sup:

Answer 9

● Flexion/Extension- 10-0-150
● Pronation- 0-75
● Supination- 0-85

Question 10

What percentage of the axial load goes through each articulation at the elbow?

Answer 10

Radiohumeral- 60%

Humeroulnar- 40%

Question 11

What structure helps transmit this load from radius to ulna in UE weightbearing?

Answer 11

Interosseus membrane

Question 12

When pulling a door open, what structure helps transmit force from radius to ulnar prior to reaching elbow joint?

Answer 12

Oblique cord

Question 13

Where does the axis for flexion/extension lie at the elbow? How does this affect motion at the joint?

Answer 13

Bisects the trochlea (obliquely). The motion does not take place in a strictly sagittal direction (some rotation and add/abduction accompany flexion/extension).

Question 14

Where does the axis for pronation/supination lie? How does this affect motion at the joint?

Answer 14

Through the heads of each bone (not along the longitudinal axis of radius). Open chain motion: radius will roll on ulna. Closed chain motion: ulna will rotate around radius.

Question 15

Normal Limitations to Extension at Elbow

Answer 15

● restriction by olecranon against fossa

● occasionally anterior capsule tension

Question 16

Abnormal Limitations to Extension at Elbow

Answer 16

● short brachialis

● passive insufficiency of biceps

Question 17

Normal Limitations to Flexion at Elbow

Answer 17

● mass of biceps
● posterior capsule tension
● impaction of bony surfaces (radial head or coronoid in fossa)

Question 18

Abnormal Limitations to Flexion at Elbow

Answer 18

● passive insufficiency of triceps

Question 19

Normal Limitations to Pronation at Elbow

Answer 19

● bony (shaft of ulna contacting radius)
● tension in posterior R/U ligament
● possibly posterior MCL

Question 20

Abnormal Limitations to Pronation at Elbow

Answer 20

● passive insufficiency of supinators

● shoulder/elbow position will not affect range if supinator is tight, but will affect it if biceps is tight

Question 21

Normal Limitations to Supination at Elbow

Answer 21

● oblique cord
● anterior ligament of inferior R/U joint
● interosseus membrane

Question 22

Abnormal Limitations to Supination at Elbow

Answer 22

● passive insufficiency of pronators

● elbow position will not affect range if pronator quadratus is tight

Question 23

What force(s)/motions does MCL resist?

Answer 23

resists valgus forces overall

Question 24

What force(s)/motions does LCL resist?

Answer 24

resists varus forces overall

Question 25

What force(s)/motions does Annular ligament resist?

Answer 25

prevents radial head from dislocating. Resists distraction of the RH joint.

Question 26

What force(s)/motions does Interosseous membrane resist?

Answer 26

prevents proximal displacement of radius on ulna

Question 27

Proximal Radioulnar Joint: Open chain pronation...OK? AK? (roll + slide)

Answer 27

OK: Roll ant. AK: Glide post.

Question 28

Proximal Radioulnar Joint: Open chain supination....OK? AK?

Answer 28

OK: Roll post. AK: Glide ant.

Question 29

Proximal Radioulnar Joint: Closed chain pronation...OK? AK? (roll + slide)

Answer 29

OK: Roll ant. AK: Glide ant.

Question 30

Proximal Radioulnar Joint: Closed chain supination...OK? AK? (roll + slide)

Answer 30

OK: Roll post. AK: Glide post.

Question 31

Which muscles produce Flexion?

Answer 31

Biceps (active with flexion and supination) Brachialis (largest/strongest flexor) Brachioradialis (longest flexor)

Question 32

Which is greater? Flexion torque or extension torque? Flexion force or extension force?

Answer 32

Flexion torque is 70% greater | Flexion force is 25% greater in supination (blame biceps)

Question 33

Which muscles produce Extension?

Answer 33

Triceps | Anconeus

Question 34

Which muscles produce Pronation?

Answer 34

Pronator teres | Pronator quadratus

Question 35

Which muscles produce Supination?

Answer 35

Supinator (recruited first) Biceps Brachioradialis (supinates to neutral)

Question 36

Anconeus

Answer 36

PA: post side of lateral epicondyle of humerus DA: between olecranon process and proximal surface of post side of ulna Action: elbow extension; longitudinal and M-L stability along humeroulnar joint

Question 37

Biceps Brachii

Answer 37

PA: Long Head: supraglenoid tubercle of scapula Short Head: apex of coracoid process of scapula DA: bicipital tuberosity of radius Action: shoulder flexion, elbow flexion, forearm supination

Question 38

Brachialis

Answer 38

PA: distal anterior surface of humerus DA: coronoid process and tuberosity on proximal ulna Action: elbow flexion

Question 39

Brachioradialis

Answer 39

PA: upper ⅔ lateral supracondylar ridge of humerus DA: near styloid process at distal radius Action: elbow flexion, rotation of forearm (depending on position in reference to neutral forearm)

Question 40

Pronator Quadratus

Answer 40

PA: anterior surface of distal ulna DA: anterior surface of distal radius Action: forearm pronation

Question 41

Pronator Teres

Answer 41

PA: Humeral head: medial epicondyle Ulnar head: medial to tuberosity of ulna DA: lateral surface of middle radius Action: forearm pronation, elbow flexion

Question 42

Supinator

Answer 42

PA: lateral epicondyle of humerus, radial collateral ligament, annular ligament, superior crest of ulna DA: lateral surface of proximal radius Action: forearm supination

Question 43

Triceps Brachii

Answer 43

PA: Long Head: infraglenoid tubercle of scapula Lateral Head: post humerus, superior and lateral to radial groove Medial Head: post humerus, inferior and medial to radial groove DA: olecranon of ulna Action: ● Long Head: shoulder extension, shoulder adduction, elbow extension ● Lateral Head: elbow extension ● Medial Head: elbow extension (also drawing elbow capsule taut during extension)