tF and Upper P Questions

Which of the following best describes the "Golden Period" in the context of upper limb prosthetics?

A. Fit a prosthesis with the greatest level of technology as soon as possible

B. Fit a prosthesis within 60 days after amputation for best outcomes

C. Fit a prosthesis with a maximal level of cosmesis even if at the expense of function

D. Fit a prosthesis within 30 days after amputation for best outcomes

D. Fit a prosthesis within 30 days after amputation for best outcomes

Name the type of harness shown above

Figure 9

A patient using step up hinges flexes their socket 35deg, this would cause ____ deg of prosthetic forearm movement.

70 degrees

For a patient with a long trans radial amputation, what range of motion for residual pro/supination would you expect?

100-120 degrees

Name A-E

A - Retainer/base plate

B - wrist unit

C - Flexible hinges

D - Anterior support strap

E - Control strap

The leading cause of upper limb amputation is….

Trauma

Which of the following socket designs utilizes self-suspension from a tight ML with a lower anterior trimline?

Northwestern

What is the optimal location for the control attachment strap?

Inferior 1/3 of scapula

What effect does sewing the cross point on a figure of 8 harness have on excursion (when compared to using a Northwestern ring)?

Increases excursion (allows more motion of the cable with less body motion)

What body motion(s) are most commonly used to activate a body powered Figure-8 harness?

Glenohumeral flexion

Biscapular abduction

How much excursion is necessary to fully open a body powered voluntary open hook?

A. 4 inches

B. 60 mm

C. 50 cm

D. 1 inch

E. 5 cm

E. 5 cm

List an advantage of a passive prosthesis as compared to other prostheses.

A passive prosthesis is more cosmetically appealing compared to other prostheses and can also be specific to recreational use. 

List a disadvantage to a transradial body powered prosthesis

The patient has to produce their own force to utilize it, expending more energy compared to other options. 

List a disadvantage of a transradial externally powered prosthesis

Skin issues, such as the skin surface being too wet or too dry, oily skin, hairy, or have scarring/skin grafts can interfere with the externally powered prosthesis

What is an advantage of a voluntary closing terminal device

Voluntary closing terminal devices allow patients to decide how much force they need to pinch certain objects, not needing to rely on rubber bands and having a prosthetist add those bands. 

What is a disadvantage of a voluntary closing terminal device

Voluntary closing terminal devices are not great for repetitive tasks. 

When are lyre shaped tines on a terminal device more advantageous than canted shaped tines?

Lyre shaped tines on a terminal device are more advantageous than canted shaped tines when the patient is working on a smooth, working surface and needing to grip things in a straight shot versus an angle

For a patient with a mid-length transradial amputation, what range of combined residual pro/supination motion would you expect?

60-100 degrees

How much grasping force is present when using a Hosmer #5 VO hook with 3 tension bands?

4.5 lbs

Typically speaking, how much excursion is necessary to fully open a Hosmer #5 hook?

50 mm

What is the ratio of socket to prosthetic forearm motion that occurs with step-up hinges?

1:2

What terminal device is better for fine motor skills? Hook or hand?

Hook

The ideal timetable for fitting a definitive body powered transradial prosthesis is…

A. 2-4 wks

B. 6-12 wks

C. 1-3 months

D. 4-6 months

B. 6-12 wks

What harness components are still present in a self-suspending body powered upper extremity prosthesis? (Choose all that apply)

A. Anterior support strap

B. Axilla loop

C. Control strap

D. Hinges (flexible or rigid)

Axilla loop and control strap

Which hook is the lightest?

A. 7

B. 5

C. 10X

D. 88X

C. 10X

Which hook is the longest?

A. 10X

B. 12

C. 88X

D. 99X

C. 88X

Which hook is made out of a different material than the others?

A. 7

B. 8

C. 10X

D. 555SS

C. 10X

A cosmetic glove that is made out of silicone is generally (choose all that apply)

A. Less expensive

B. More expensive

C. Less durable

D. More durable

More expensive and more durable

Which harness should you use for a patient who prefers a body powered control system but cannot tolerate pressure on the contralateral axilla?

A. Myoelectric

B. Fair-lead

C. Figure 8

D. Figure 9

E. Shoulder saddle and chest strap

E. Shoulder saddle and chest strap

What hinges are best indicated for a very short transradial patient with 5/5MMT and full range of elbow motion?

A. Flail arm hinges

B. Flexible hinges

C. Polycentric hinges

D. Step up hinges

C. Polycentric hinges

Your patient has a job where she has to grab and forcefully supinate an object.  Which wrist unit would be best for her?

A

B

C

D

E

E

Which wrist unit is indicated for a patient who requires the cosmesis for a body powered hand and requires additional flexion to accomplish tasks at midline? 

A

B

C

D

E

D

Which is a correct description of this following TD’s?

Canted

Work hook

Voluntary Closing

Lyre

Canted - C

Work hook - A

Voluntary closing - D

Lyre - B

What is the name of the single housing control cable commonly used on body powered transradial prostheses?

Bowden cable

Using the picture of a cable below, name each of the labeled components (A-C).

A - Hanger

B - Housing

C - Crossbar attachment

Using the picture of a cable below, name each of the labeled components (A-E).

A - Base plate

B - Rubber disc

C - Retainer

D - Bowden cable

E - Triple swivel

T/F - The shorter the TH amputation the further onto the torso the trim lines may need to extend to prevent rotation.

TRUE

How much excursion is required to fully flex a body powered TH elbow?

50 mm

T/F - Transhumeral elbow may come with a lift assist option that may be internal to the forearm or external to the elbow joint.

TRUE

What is the purpose of the split cable housing on the Fair Lead system?

A. To allow the two section of housing to be pulled towards each other to flex the elbow

B - To maintain the length of the cable around a curve (elbow flexed or extended)

C - To prevent an external rotation moment of the elbow unit

D - To assist in stabilizing the socket on the patients body (stability and suspension)

A. To allow the two sections of housing to be pulled towards each other to flex the elbow.

T/F - A patient with a short to mid length transhumeral amputation can actively internally or externally rotate their prosthetic forearm using their ipsilateral humerus.

FALSE

The forearm lift assembly tab maintains the control cable _______ to the elbow axis. The lift tab is usually positioned _____ from the elbow axis. You can attach the lift tab more distally on the forearm to _____ the force to flex the elbow but will require _____ excursion to fully flex the elbow.

anterior; 3 cm; decrease; more

A fair-lead cable system is an example of a _________ control cable and a _________ elbow lock.

Sequential; dedicated

T/F - In a transhumeral prostheses the elbow unit always located inline with the long axis of the humerus.

FALSE

Which elbow is appropriate for a very long transhumeral/elbow disarticulation? Outside or inside locking hinges?

Outside locking hinges

Which elbow would be best for a patient with a mid length transhumeral amputation, who will receive a hybrid prosthesis with a body powered elbow and externally powered terminal device. 

A. Outside locking hinges

B. Internal locking hinges

C. Friction elbow

D. Ergo elbow

D. Ergo elbow

T/F - The use of a lift assist may allow the the forearm lift tab to be placed closer to the elbow axis.  This could allow the patient to use the same force to flex the elbow but require less excursion to fully flex the elbow.

TRUE

When fabricating a control cable for the terminal device, which conditions should be met first?

A. Make sure there is 1/4" space between the distal cable housing and the triple swivel when the hook pronated and fully closed

B. Make sure there is 1/4" space between the distal cable housing and the triple swivel when the hook supinated and fully open

B. Make sure there is 1/4" space between the distal cable housing and the triple swivel when the hook supinated and fully open

When fabricating a control cable for the terminal device, which conditions should be met when determining the cable length?

A. Make sure there is 1/4" space between the proximal cable housing and the hanger when the hook pronated and fully closed

B. Make sure there is 1/4" space between the proximal cable housing and the hanger when the hook supinated and fully open

A. Make sure there is 1/4" space between the proximal cable housing and the hanger when the hook pronated and fully closed

T/F - The amount of excursion required to fully open the terminal device in a body powered Fair-lead system is influenced by the amount of flexion at the elbow.

TRUE

Which control system creates a larger functional envelope for the patient?

A. Body powered

B. External powered (myoelectric)

B

A patient is using a terminal device with proportional control using dual sites.  They contract their wrist flexor muscles at a low level that does reach threshold.  How does the terminal device respond?

A. Opens slowly

B. Closes slowly

C. No movement

D. Opens quickly

B. Closes slowly

Which of the following are necessary signal processing steps to create a "clean" myoelectric signal? (select all that apply)

A. Expansion

B. Rectification

C. Filtering

D. Amplification

E. Calibration

B. Rectification

C. Filtering

D. Amplification

What types of patients could be candidates for pattern recognition (COAPT) who were previously poor candidates for traditional myoelectric control? (select all that apply)

A. Working in adverse environments (water, sand, dirt)

B. difficult switching between modes/joints

C. Poor isolation of myo sites

D. Weak myo signals

B. difficult switching between modes/joints

C. Poor isolation of myo sites

D. Weak myo signals

Explain one option for how a patient with only one myo site can control 2 separate functions of their terminal device.

They could do an alternating control type - in which the patient would contract once to "open," relax, then contract again to "close." 

You are evaluating a transradial patient for a dual site myoelectric prosthesis.  Describe the process of myo site testing for this patient.  Comment on what you are looking for regarding location of the site(s) and how you are instructing the patient throughout this process.

I would evaluate each potential myo site, that being the wrist flexors (anterior side) and the wrist extensors (posterior side) for any scarring, burns, hair, or oilly skin that could interfere with the process. Assuming the patient has none of those, I would proceed to place the myo receptors on each side and instruct the patient to envision they are opening and closing their hand, closing their eyes or mirroring this movement with their sound side. I would ensure also that the receptors are longitudinally placed on the muscle, and that they are not crossing over to other muscles. As they do these movements/contractions, I would instruct them to do it at their most comfortable level, not flexing so much that they fatigue and not too soft that no contraction is felt. 

T/F - The use of a lift assist may allow the forearm lift tab to be placed closer to the elbow axis.  This could allow the patient to use the same force to flex the elbow but require less excursion to fully flex the elbow. 

TRUE

T/F - Transhumeral elbows may come with a lift assist option that may be internal to the forearm or external to the elbow joint.

TRUE

What elbow unit allows simulated internal and external rotation of the shoulder?

A. Outside locking hinges

B. Flail arm hinges

C. Internal locking hinges

D. Flexible elbow hinges

C. Internal locking hinges

What transhumeral control system allows simultaneous control of elbow flexion and terminal device activation?

A. Triple control

B. Dual control

C. Fair-lead control

D. Bowden control

A. Triple Control

To activate an elbow lock on a body powered fair-lead control system, the patient needs

A. 12mm excursion from shoulder depression or abduction

B. 25mm excursion from shoulder elevation or flexion

C. 25mm excursion from shoulder depression or abduction

D. 12mm excursion from shoulder elevation or flexion

A. 12mm excursion from shoulder depression or abduction

Assuming that the cable housing length has already been set - what elbow position should a transhumeral prosthesis be oriented when determining the control cable length in a fair-lead system?

A. The elbow should be in full flexion

B. The elbow should be in full extension

B. The elbow should be in full extension

How does the instructor determine the length of the cable housing distal to the base plate on a transradial body powered prosthesis with a voluntary opening hook?  Choose all that apply:

A. hook fully opened

B. 1/4” distance between triple swivel and distal cable housing

C. 1/16” distance between hanger and proximal cable housing

D. Hook supinated to shortest distance from thumb of hook to base plate

E. 0 distance between triple swivel and distal cable housing

F. 1/16" distance between triple swivel and distal cable housing

G. 0 distance between hanger and proximal cable housing

H. Hook pronated to longest distance from thumb of hook to base plate

I. Hook partially opened

J. 1/4" distance between hanger and proximal cable housing

K. Hook fully closed

A. hook fully opened

B. 1/4” distance between triple swivel and distal cable housing

D. Hook supinated to shortest distance from thumb of hook to base plate

How does the instructor determine the overall cable length for a transradial body powered prosthesis with a voluntary opening hook?  Assume that the cable housing length has already been set.  Choose all that apply:

A. hook fully opened

B. 1/4” distance between triple swivel and distal cable housing

C. 1/16” distance between hanger and proximal cable housing

D. Hook supinated to shortest distance from thumb of hook to base plate

E. 0 distance between triple swivel and distal cable housing

F. 1/16" distance between triple swivel and distal cable housing

G. 0 distance between hanger and proximal cable housing

H. Hook pronated to longest distance from thumb of hook to base plate

I. Hook partially opened

J. 1/4" distance between hanger and proximal cable housing

K. Hook fully closed

H. Hook pronated to longest distance from thumb of hook to base plate

K. Hook fully closed

J. 1/4" distance between hanger and proximal cable housing

Which elbow unit would be best for a patient with an elbow disarticulation or very long transhumeral amputation?

A. Outside locking hinges

B. Ergo arm

C. Endoskeletal elbow

D. Internal locking hinges

A. Outside locking hinges

If the forearm lift tab is located 5cm distal to the elbow joint, what effect will that have on the prosthesis when compared to the recommended attachment position? 

_________exertion will be needed to lift the forearm (flex the elbow).

_________ excursion is required to fully lift the forearm (flex the elbow).

Less exertion will be needed to lift the forearm (flex the elbow).

More excursion is required to fully lift the forearm (flex the elbow).

Your transhumeral patient has a glenohumeral abduction contracture of 11 degrees and you attach the elbow unit in line with the long axis of the socket.  Would the patient experience high pressures in the socket?

A. No

B. Yes - proximal medial and distal lateral

C. Yes - proximal lateral and distal medial

B. Yes - proximal medial and distal lateral

Forearm lift tab assembly is used with which control cable configuration?

A. Fair lead

B. Triple control

C. Bowden

A. Fair lead

What happens in a fair-lead control system if the weight of the forearm is greater than the tension force required to open the voluntary opening terminal device on a transhumeral prosthesis with an unlocked elbow, when a patient first generates 3cm of cable excursion

A. Terminal device opens

B. Elbow flexes

A. Terminal device opens

What is the function of the lateral support strap on a transhumeral figure 8 harness?

The lateral support strap is meant to help with suspension of the prosthesis, preventing lateral tipping of the socket, therefore creating more stability. 

Your patient uses a fair-lead cable system but is unable to fully flex their elbow.  What is one patient-related cause and one prosthetic cause for this lack of range?

One patient-related cause could be that the patient is simply not strong enough to generate the force needed to fully flex the elbow. 

One prosthetic cause could be that there was not enough length of cable left between the two cable housings for the housings to meet at the elbow joint/between the forearm lift assembly and the crossbar attachment. 

Why is there elastic on the distal portion of the anterior support strap of a transhumeral figure 8 harness?

Allows for the ~1/2” excursion to activate the elbow lock

What hook are all other types of hooks compared to?

Model 5

The model 5 hook is a ____ hook with ______ tines constructed out of ________ and sized for a(n) _______. This device weighs ________.

VO; canted; stainless steel; adult; 8 oz

How does the length of a Hook correlate to a patient’s intact hand?

(how do you determine which size hook to order for a patient)

The length is determined based on the length from the wrist to tip of thumb on the sound side. 

Approximately how much pinch force is generated by each tension band?

A. 1.5 lb

B. 2.5 lb

C. 1 lb

D. 4 lb

A. 1.5 lbs

What is an indication for a TD with a P?

It is indicated if the patient is a child and needs a softer coating to not hurt themselves or others, making the pinch hurt less/not damage items that are grasped. It could also be indicated for those who want a more cosmetic look, coming in two different "skin tones." 

What are the 2 functions of a Wrist unit?

1. Attachment site for TD - also allowing for interchange of TDs

2. Allows for positioning of TD

   1. Pronation/supination

   2. MAY allow flexion/extension

   3. Can be friction, Locking, or Both

What is a benefit of a Sierra Wrist Flexion unit over a FW Flexion Friction Wrist?

The Sierra Wrist Flexion unit can accomodate both a hand and/or a hook whereas the FW Flexion Friction Wrist cannot because the hands have too large of adapters for the FW unit whereas the Sierra allows enough room for both options. 

What are 2 benefits of a Quick Disconnect wrist?

1. Allows for quick change of hands/hooks

2. Positive locking

What patient population is this TD designed for?

Children

What is a possible cause for a patient with an Quick Disconnect wrist unit to have unintentional pronation / supination?

The Quick Disconnect wrist unit could be not have the hand/hook locked in place due to not having the hand/hook fully seated. 

Which hook is longest?

A. 88X

B. 7LO

C. 99

D. 12

B. 7LO

Which hook is TD is lightest?

A. 8

B. 5

C. 99X

D. 7

C. 99X

What measurement is needed to select the correct size hand for a patient?

Circumference at the MCP

Your patient is concerned that their hook  will damage items that they grasp.  Which options would reduce this risk

A. Surgical tubing on tines

B. Serrations

C. Nitrile on tine (X)

D. Plastizol coating

A. Surgical tubing on tines

C. Nitrile on tine (X)

D. Plastizol coating

Which hook would be best for a patient with a medium size hand and a short residual limb

A. 88X

B. 5XA

C. 9

D. 5

A. 88X

Which wrist would be best for a patient with a long transradial amputation who uses the prosthesis only for social occasions with a non-prehensile hand?

A. Quick Disconnect wrist

B. Oval Friction wrist

C. Economy Friction wrist

D. Sierra Wrist Flexion unit

B. Oval Friction wrist

In a myoelectric prosthesis, what is the purpose of the surface electrode?

Record muscle signal from the skin

Which of the following options is able to provide the highest grip force?

A. Voluntary open hook

B. Externally powered hand

C. Voluntary open hand

B. Externally powered hand

In regards to medical necessity policy for a myoelectric device, provide at least one reasoning you could use to demonstrate why a body-powered device cannot be used or is insufficient for your patient.

focusing on inability to wear a harness and/or overhead activities/other needs outside of the limited functional envelope of body powered devices

Which of the following are true about pattern recognition? (select all that apply)

A. Utilizes a greater number of electrodes compared to dual site control

B. Can be utilized with a gel liner interface

C. Focused more on the muscle patterns than the amplitude of one specific signal

D. Most beneficial for long trans-radial patients only operating a TD

A. Utilizes a greater number of electrodes compared to dual site control

B. Can be utilized with a gel liner interface

C. Focused more on the muscle patterns than the amplitude of one specific signal

Which of the following best describes how increasing the "gain" of the electrode affects the myoelectric signal?

A. Filters out noise to isolate the signal

B. Decreases the signal strength to prevent incidental operation

C. Amplifies the myoelectric signal

D. Reduces battery consumption

C. Amplifies the myoelectric signal

T/F - Multiarticulating hands are capable of utilizing both power and precision grasps. 

TRUE

A patient is using a terminal device with proportional control using dual sites.  They contract their wrist flexor muscles at a low level that does not reach threshold.  How does the terminal device respond?

A. Opens quickly

B. No movement

C. Opens slowly

D. Closes slowly

B. No movement

What type of grip pattern does a single DOF externally powered hand utilize?

A. 3 jaw chuck

B. Lateral

C. Spherical

D. Power

A. 3 jaw chuck

What is removed in an Interscapulothoracic amputation?    

Lateral 2/3 of clavicle

Scapula

A patient with a shoulder disarticulation prosthesis who is holding a weight in their prosthetic hand with the elbow flexed will notice higher forces:  

Proximal posterior

Distal anterior

Most shoulder disarticulation prostheses are suspended using a

A. self suspension

B. chest strap

C. figure 8 harness

D. figure 9 harness

B. chest strap

The modern frame style shoulder disarticulation prosthetic sockets offer the following benefits over the conventional sockets.   (choose all that apply)

A. less shear forces due to the lamination against the patients skin

B. heat dissipation

C. greater surface area of prosthesis in contact with the patient

D. Weight reduction

B. heat dissipation

D. Weight reduction