Prosthetic Components & Design - suspension types Flashcards
suspension methods
- suspension belts/cuffs
- lanyard
- pin lock
- suction
- elevated vacuum
what is the goal of suspension methods
keep the prosthesis attached to the user during swing phase of gait
what is lanyard suspension
lanyard attached to end of liner is threaded through a hole in the socket and pulled tight and attached to the outside of the socket
pros of lanyard suspension
- very secure (mechanical ratchet straps or strong velcro)
- consistent alignment
- does not take much space at bottom of socket
cons of lanyard suspension
visible from outside of socket
does AKA or BKA use lanyard suspension more
AKA
what is pin lock suspension
- most common type
- mechanical connection between a metal pin on the distal end of the liner that fits into a lock built into the distal end of the socket
pros of pin lock suspension
- very secure, mechanical connection
cons of pink lock suspension
- can cause suction effect
- difficult to align if deaf or blind
- shuttle lock takes up space in socket
does BKA or AKA use pin lock more
BKA
what is suction suspension
one way valve is fit into the side of the socket, when the user pushes the limb into the socket air is expelled creating suction on the limb
pros of suction suspension
- good for blood flow
- very good suspension
- provides for fluctuating limb volume
cons of suction suspension
can wear out liners quickly
does BKA or AKA use suction suspension
AKA
what is elevated vacuum suspension
advanced version of suction suspension through use of a motorized pump to maintain negative pressure inside socket
pros of elevated vacuum suspension
- very comfortable
- allows for imb volume fluctuations
cons of elevated vacuum suspension
- heavy
- must be charged
- extra component that takes up space at the end of the socket
what kind of sockets does elevated vacuum suspension use
total surface bearing (transtibial)
does BKA or AKA use elevated vacuum suspension
BKA
liner
interface between the user’s skin and the socket
silicone liner
- typically used with pin-lock systems
- soft and resistant to pressure, durable
- good for everyday use
polyurethane liner
good at absorbing pressures, used with vacuum and suction suspension systems
copolymer liner
good for low activity level (K1/K2) and for total surface bearing sockets
socks
- NOT the same as a liner
- worn between the liner and socket to accomodate extra space
- easy to don/doff as volume changes throughout the day
