Hinges Flashcards
What is the patient population that uses Rigid hinges?
Amputation level at or above mid forearm
What is the patient population that uses flexible hinges?
Long TR, wrist disarticulation, trans-carpal amputation
* the key is that the patient has available pronation and supination
Do the rigid hinges restrict voluntary pronation/supination?
No
What is the primary advantages of rigid hinges?
Protection of the residual limb against torque during prosthetic use
What type of stability do single axis hinges use between the socket and residual limb during prosthetic use?
Axial (rotation) stability
Is proper alignment crucial for single axis hinges?
Yes. Without proper alignment, patient won’t be able to maintain normal ROM for elbow flexion and extension
What is the patient population that uses single axis hinges?
Short TR
Why should the single axis hinges be placed in pre-flexion for short TR patient?
- Help reduce the weight on the RL
2. Help prevent elbow hyperextension
What is the patient population that uses polycentric hinges?
Short TR, very short TR
What is an advantage of the polycentric hinges?
Reduce the tendency of muscle bunching at the elbow during flexion
What is the result of muscle bunching?
Higher trimlines to stabilize the short RL
More “room” is achieved with the polycentric hinges during elbow flexion in which area?
Cubital area
What is the patient population and what kind of socket design that use the step-up hinges?
Very short TR, socket design that incorporates high anterior trim lines, split socket design
What is the ratio that used to amplify the excursion of the anatomical elbow?
2:1
Ex: if pt only has 50 degrees of available elbow flexion, using the hinge will allow 100 degrees ROM to be reached
What are the two types of step-up hinges and the cable used?
- Sliding action (split-housing cable)
2. Geared (Bowden cable)
