Terminal devices and wrist units Flashcards
Main difference between myoelectric and microswitch-controlled externally powered terminal device
Myoelectric uses surface electrodes on muscles of residual limb to activate terminal device.
Microswitch uses a button or switch to activate terminal device.
What determines prehensile force of the voluntary opening terminal device?
Number and type of rubber bands/springs
Which body-powered terminal device is more physiologic
Voluntary closing terminal device
What additional feature to a wrist unit should be considered for a bilateral UE amputee?
A wrist flexion unit to help with ADLs
What is the advantage of a locking wrist unit?
Prevents accidental rotation of the wrist when carrying something
What is a combination wrist flexion unit
Combines locking and friction types of wrist units to allow locking in wrist flexion
Three types of terminal devices
- Passive
- Body-powered
- Externally powered
What determines prehensile force of the voluntary closing terminal device?
Strength of the individual
2 main types of wrist units
- Friction wrist unit
2. Locking wrist unit
Most common type of body-powered terminal device
Voluntary opening terminal device
What is the main disadvantage of a voluntary closing terminal device?
User has to maintain constant pull on harness for prolonged prehension
Is the rotation function of a wrist unit passive or active?
Passive - so it is rotated by the user’s other hand or by pushing it against something
2 types of body powered terminal devices
Voluntary opening or voluntary closing
What is the purpose of a passive terminal device
Cosmetic purpose. No function
What is the purpose of a wrist unit?
Provides pronation and supination of the hand
