Upper Extremity Prosthetics Study Guide (Ricci) - Engineering Terms

What is the #1 reason for UE amputation age 15-24?

trauma

What is the #1 reason for UE amputation age 0-15?

congenital

What are reasons for UE amputations?

- trauma

- congenital

-cancer

-disease

What are the types of UE prosthetics?

-cosmetic (finger or partial hand)

-body powered

-myoelectric

-hybrid of myoelectric / body powered

When are cosmetic prosthetics used?

-usually for finger, partial hand, or transradial amputations

-passive

-not functional

Describe a body powered UE prosthesis

-cable and harness system

-body movements at the shoulder & thorax control movement

-more durable, but less cosmetically appealing

-heavy & expensive

The movements of a body powered prosthesis are usually based off of what activity?

eating

What are the components of a body powered device?

-socket

-suspension

-cable

-elbow & wrist joint

-terminal device (hand or hook)

Describe the socket of the body powered device

-flexible inner liner (comfort & pressure relief)

-hard carbon fiber outer lines (attachment for cables to control the prosthesis and shape the limb)

What are the 3 types of suspensions for a body powered device?

-harnessed

-self suspending

-suction

What is the most commonly used suspension system for UE?

harness system

Describe the harness system

-most common

-figure 8 loops around the axilla on unaffected side

-provides anchor for prosthesis

-counterforces for the cable system to control the prosthesis

Describe the self suspending system for UE. Who is it commonly used with?

-no harness

-less wt, not as cumbersome

-commonly seen with TRA, wrist & elbow disarticulations

Describe the suction suspension system. Who is it commonly used with?

-no harness (less wt, not as cumbersome)

-commonly used with THA

-can use a pin, suction with 1-way valve, or gel & silicone iners

What is a cable control system?

the system used to link physical movement to the prosthetic movement

What do the following motions commonly allow for the prosthetic device to do within the cable control system?

-shoulder flexion

-scapular protraction

-scapular retraction

-shoulder depression

-shoulder elevation

-shoulder flexion = elbow flexion

-scapular protraction = TD close

-scapular retraction = TD open

-shoulder depression = lock elbow

-shoulder elevation = unlock elbow

What are the types of terminal devices?

-hook

-hand

-recreational device

Describe the hook as a TD

-most functional

-good for gross motor activities (heavy things)

Describe the hand as a TD

-most cosmetic

-not always best functionally

-EX) I-limb, pro-digits

Desccribe recreational device as TD

-different attachments that can be used for different activities

-has interchangeable parts

T or F: A hand as a TD is not always the best functional device, even with a myoelectric device

True

What are 2 types of electric prosthesis? What is the role of an electric device?

myoelectric and switch control

--improves function for fine motor activity

--better grip strength

--more maintenance

--heavy & expensive

What is a myoelectric device? What are the types and describe them?

-device that uses muscle signals thru electrodes to trigger prosthetic activity

-2-site (dual site) has separate electrodes for paired prosthetic activity; increases physiologic control

-1 site (single site) has 1 electrode to control both functions of a paired activity; used with decreased muscle control

-sequential / multistate controllers is one site for multiple functions

What type of myoelectric device is the best?

dual site (2 site)

What type of device is described below?

Jerry uses his tricep contraction to close his TD while the biceps contract to open his TD

2-site myoelectric device

What type of device is described below?

Harry fires his biceps to close his TD to grap a fork. Then he fires his biceps again to open the TD and let go of the fork

Single site myoelectric device

What device is described below?

Billy contracts his biceps 2x quickly to flex his wrist. However, when he slowly contracts his bicep once, his wrist extends

sequential myoelectric device

If a young child who used to play video games alot now has an amputation and requires a UE prosthesis, what device may indicated for him? why?

sequential / multistate controller; this device requires control that can be difficult, but techniques to use are similar to video games so he may be able to work it with less frustration

What is a switch control devices? When is this used?

-electric device in which switched are used to control movement instead of muscle control

-used when muscle control sites aren't available, or pts can't master myoelectric prosthesis

How are switch control devices activated?

-pressure from residual limb

-different movements

-contralateral limb

-caregiver

What are pre-prosthetic PT interventions to do?

-proximal UE strengthening

-ROM

-Desensitization

-edema control

A prosthetic fitting for an UE within what time period has greatest success?

7-30days

What should PT involve in regard to prosthetic training?

-training specific movements

-increased repetitive movements to learn control of prosthesis

-fine motor activities

T or F: With an UE prosthesis, pressure sensitive areas are not as great of a concern as LEs due to non weightbearing thru prosthesis

True

T or F: The prosthetist and OT and PT often co treat to optimize prosthetic function

True

T or F: It is important to fit a pt early with a UE device due to early frustration with it and getting used to life without one

True

T or F: A hand TD is more commonly used than a hook due to it looking more normal

False; hook used more due to it being more functional