UE Prosthetics Flashcards
What age is appropriate to begin fitting UE prostheses?
“Sit to fit”
What is an advantage of canted-style TD?
Improved line of sight
What is an advangtage of lyre shaped TDs?
Improved cylindrical grasp/ability to hold round objects
What is the most common prehension pattern for mechanical hand TDs?
Palmar
Describe the single axis hinge
Eliminates pronation/supination
Offers a HD option
Describe flexible hinges - when are the essential?
Allows for pronation/supination
Offers a HD option
Necessary to bilateral fittings
When are outside locking hinges most appropriate? How many positions are available for locking?
Elbow disarticulation
7 locking positions; 5 in the HD version
What is an advantage of a polycentric hinge?
Reduced cubital bunching
When are stump activated hinges indicated?
Very short below elbow
How many locking positions are available with stump activated hinges?
Five
Which hings requires use of a split housing cable?
Stump activated hinge
When are step up hinges indicated?
Very short below elbow
What is the benefit and trade-off associated with step-up hinges?
Improved ROM; however, increased force is required
What hinge is indicated for a brachial plexus injury?
Flail arm hinge
What is on the medial side of the flail arm hinge? What is on the lateral side?
Lock - medial side
Spring - lateral side
How many locking positions does a large mechanical elbow have?
11 ( 8 HD )
How many locking positions does a medium mechanical elbow have?
11 ( 9 HD )
How many locking positions does a child-sized mechanical elbow have?
10 (no HD option)
Name three types of shoulder units
Abduction joint
Flexion abduction joint
Universal shoulder design
Optimal cross point in Figure 8 harnessing
Slightly inferior to C7, biased toward the sound side
What is the main suspension strap in a TR Figure of 8 harness?
Anterior suspension strap
What is the function of the anterior suspension strap in the transhumeral harness?
Unlock the elbow
What is the main suspension strap in TH harnessing?
Lateral suspension strap
What is the force/excursion requirement for the TD? Elbow? Lock
TD: 2”, 15 lbs.
Elbow: 2.5”, 9 lbs.
Lock: 0.75”, 3 lbs.
List two control issues which indicate more power is required.
Forearm doesn’t go up, TD opens with flexion
How could you correct an issue you determine requires more power?
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
List two control issues which indicate greater excursion is required.
TD not fully opening, TD doesn’t open at the mouth
How could you correct an issue you determine requires greater excursion?
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
What is the required efficiency for a TR prosthesis?
70%
What is the required efficiency for a TH prosthesis?
50%
What is the required maintained pronation-supination for a TR prosthesis? What is the required flexion?
50% pronation supination
Full flexion
What is the maximum glenohumeral flexion required to lift the TH?
45 deg.
What is axilla discomfort in a TR most likely attributed to?
Crosspoint is too close to the sound side
What is the initial preflexion for an elbow in a TH system?
10-15 deg.
Why is the elbow preflexed in a transhumeral system?
Improved mechanical advantage when initiating forearm flexion
What muscles are simulated with activation of a voluntary opening TD?
Extensor digitorum communis and the lumbricals
