Prosthetic Components & Design - suspension types

Question 1

suspension methods

Answer 1

• suspension belts/cuffs
• lanyard
• pin lock
• suction
• elevated vacuum

Question 2

what is the goal of suspension methods

Answer 2

keep the prosthesis attached to the user during swing phase of gait

Question 3

what is lanyard suspension

Answer 3

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

Question 4

pros of lanyard suspension

Answer 4

• very secure (mechanical ratchet straps or strong velcro)
• consistent alignment
• does not take much space at bottom of socket

Question 5

cons of lanyard suspension

Answer 5

visible from outside of socket

Question 6

does AKA or BKA use lanyard suspension more

Answer 6

AKA

Question 7

what is pin lock suspension

Answer 7

• 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

Question 8

pros of pin lock suspension

Answer 8

• very secure, mechanical connection

Question 9

cons of pink lock suspension

Answer 9

• can cause suction effect
• difficult to align if deaf or blind
• shuttle lock takes up space in socket

Question 10

does BKA or AKA use pin lock more

Answer 10

BKA

Question 11

what is suction suspension

Answer 11

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

Question 12

pros of suction suspension

Answer 12

• good for blood flow
• very good suspension
• provides for fluctuating limb volume

Question 13

cons of suction suspension

Answer 13

can wear out liners quickly

Question 14

does BKA or AKA use suction suspension

Answer 14

AKA

Question 15

what is elevated vacuum suspension

Answer 15

advanced version of suction suspension through use of a motorized pump to maintain negative pressure inside socket

Question 16

pros of elevated vacuum suspension

Answer 16

• very comfortable

- allows for imb volume fluctuations

Question 17

cons of elevated vacuum suspension

Answer 17

• heavy
• must be charged
• extra component that takes up space at the end of the socket

Question 18

what kind of sockets does elevated vacuum suspension use

Answer 18

total surface bearing (transtibial)

Question 19

does BKA or AKA use elevated vacuum suspension

Answer 19

BKA

Question 20

liner

Answer 20

interface between the user’s skin and the socket

Question 21

silicone liner

Answer 21

• typically used with pin-lock systems
• soft and resistant to pressure, durable
• good for everyday use

Question 22

polyurethane liner

Answer 22

good at absorbing pressures, used with vacuum and suction suspension systems

Question 23

copolymer liner

Answer 23

good for low activity level (K1/K2) and for total surface bearing sockets

Question 24

socks

Answer 24

• 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

Question 25

what is the order of components

Answer 25

• resisdual limb
• liner
• sock
• socket

Question 26

pylon

Answer 26

metal tube