UE Prosthetics

Question 1

What age is appropriate to begin fitting UE prostheses?

Answer 1

“Sit to fit”

Question 2

What is an advantage of canted-style TD?

Answer 2

Improved line of sight

Question 3

What is an advangtage of lyre shaped TDs?

Answer 3

Improved cylindrical grasp/ability to hold round objects

Question 4

What is the most common prehension pattern for mechanical hand TDs?

Answer 4

Palmar

Question 5

Describe the single axis hinge

Answer 5

Eliminates pronation/supination

Offers a HD option

Question 6

Describe flexible hinges - when are the essential?

Answer 6

Allows for pronation/supination
Offers a HD option
Necessary to bilateral fittings

Question 7

When are outside locking hinges most appropriate? How many positions are available for locking?

Answer 7

Elbow disarticulation

7 locking positions; 5 in the HD version

Question 8

What is an advantage of a polycentric hinge?

Answer 8

Reduced cubital bunching

Question 9

When are stump activated hinges indicated?

Answer 9

Very short below elbow

Question 10

How many locking positions are available with stump activated hinges?

Answer 10

Five

Question 11

Which hings requires use of a split housing cable?

Answer 11

Stump activated hinge

Question 12

When are step up hinges indicated?

Answer 12

Very short below elbow

Question 13

What is the benefit and trade-off associated with step-up hinges?

Answer 13

Improved ROM; however, increased force is required

Question 14

What hinge is indicated for a brachial plexus injury?

Answer 14

Flail arm hinge

Question 15

What is on the medial side of the flail arm hinge? What is on the lateral side?

Answer 15

Lock - medial side

Spring - lateral side

Question 16

How many locking positions does a large mechanical elbow have?

Answer 16

11 ( 8 HD )

Question 17

How many locking positions does a medium mechanical elbow have?

Answer 17

11 ( 9 HD )

Question 18

How many locking positions does a child-sized mechanical elbow have?

Answer 18

10 (no HD option)

Question 19

Name three types of shoulder units

Answer 19

Abduction joint
Flexion abduction joint
Universal shoulder design

Question 20

Optimal cross point in Figure 8 harnessing

Answer 20

Slightly inferior to C7, biased toward the sound side

Question 21

What is the main suspension strap in a TR Figure of 8 harness?

Answer 21

Anterior suspension strap

Question 22

What is the function of the anterior suspension strap in the transhumeral harness?

Answer 22

Unlock the elbow

Question 23

What is the main suspension strap in TH harnessing?

Answer 23

Lateral suspension strap

Question 24

What is the force/excursion requirement for the TD? Elbow? Lock

Answer 24

TD: 2”, 15 lbs.
Elbow: 2.5”, 9 lbs.
Lock: 0.75”, 3 lbs.

Question 25

List two control issues which indicate more power is required.

Answer 25

Forearm doesn't go up, TD opens with flexion

Question 26

How could you correct an issue you determine requires more power?

Answer 26

Move the elbow flexion attachment point distal Move the baseplate and retainer anterior and proximal Use a lighter TD Shorten the forearm Lubricate the cable

Question 27

List two control issues which indicate greater excursion is required.

Answer 27

TD not fully opening, TD doesn't open at the mouth

Question 28

How could you correct an issue you determine requires greater excursion?

Answer 28

Move the elbow flexion attachment point more proximal Move the baseplate and retainer posterior and distal Tighten the control strap Cut a rubberband Add a spring lift assist

Question 29

What is the required efficiency for a TR prosthesis?

Answer 29

70%

Question 30

What is the required efficiency for a TH prosthesis?

Answer 30

50%

Question 31

What is the required maintained pronation-supination for a TR prosthesis? What is the required flexion?

Answer 31

50% pronation supination | Full flexion

Question 32

What is the maximum glenohumeral flexion required to lift the TH?

Answer 32

45 deg.

Question 33

What is axilla discomfort in a TR most likely attributed to?

Answer 33

Crosspoint is too close to the sound side

Question 34

What is the initial preflexion for an elbow in a TH system?

Answer 34

10-15 deg.

Question 35

Why is the elbow preflexed in a transhumeral system?

Answer 35

Improved mechanical advantage when initiating forearm flexion

Question 36

What muscles are simulated with activation of a voluntary opening TD?

Answer 36

Extensor digitorum communis and the lumbricals