Final Flashcards
What’s the function of the fair-lead cable?
Allows it to control multiple functions
Used for elbow flexion/ opening and closing hook
Where is the Fair-Lead cable split?
Split at the elbow
Since the housing is split the tension on the control cable flexes the elbow when elbow is _________ and opens the TD when elbow is ___________.
Flexes elbow when elbow is unlock
Opens TD when elbow is locked
What is required when the elbow flexion attachment point is close to the mechanical elbow axis?
Less cable excursion required to make it work
More force required
What is required when the elbow flexion attachment point is far from the mechanical elbow axis?
More cable excursion required
Less force required
Where should the elbow flexion attachment point be placed?
1 1/4” distal to elbow axis
1” anterior to elbow axis
How much excursion is required for a Transradial?
5cm (2”)
How much excursion is required for a trans humeral?
11.3 cm (4.5”)
What are the components of a figure 8 harness?
A. Axilla loop B. Anterior support strap C. Lateral support strap D. Control strap E. Elbow lock control strap
Where is the cross point located?
Just to non-amputated side
Distal to C7
Axilla loop
Anchor for other harness components
Some straps attach for suspension
Some straps attach for control
Attaches to the cross point
True or False
The northwestern ring is used less frequently for TH as it gives too much freedom - lose excursion
True
What is the anterior support strap also known as?
Elastic suspension strap anterior suspension strap
Where is the anterior support/suspension strap located?
Originates at cross point
Crosses through delto-pectoral groove
Attaches in the distal anterior humeral section
Elastic distal 2/3
What is the purpose of the anterior support/suspension strap?
Helps suspend prosthesis (limited due to elastic)
Helps prevent external rotation
Helps “cock” the elbow lock
Where is the elbow lock strap located?
Originates on the upper non-elastic portion of the anterior support strap?
The elbow lock strap requires how much excursion?
1.3 cm
Where is the lateral support strap located?
Originates just posterior to the highest point of the Axilla strap
Stitched to the anterior support strap
Lateral end passes just anterior to acromion
Attaches close to proximal socket trim line
What does the lateral support strap do?
Suspends
Helps limit external rotation when control cable engaged
Where is the control cable located?
Originates at the cross point
Runs obliquely downward across the back, mid scapula
What happens when the control cable is too high?
Not enough cable excursion to operate elbow and TD
What happens when the control cable is too low?
Requires too much force to operate
What is the purpose of the cross-back strap?
Helps reduce the vertically directed force of the axillary loop
Helps prevent superior migration of cross point -keeping inferior to c7
Helps keep the control cable in the mid-scapula position
True or false
The shoulder saddle harness is more challenging due to the required need for excursion in trans humeral
True