Polypropylene shrinkage - Prosthetic outer sockets/frames
William Lifford
Description
Collection
Title:
Polypropylene shrinkage - Prosthetic outer sockets/frames
Creator:
William Lifford
Date:
9/13/2003
Text:
Hello colleagues,
Lately it seems as though many of our facility's polypropylene sockets shrink quite a bit. Sometimes, though, the shrinkage seems to be circumferential and other times it seems to be longitudinal.
What are some methods we can use to control or reduce this shrinkage? I would rather not laminate everything, due to the dust created while grinding laminated sockets; however, it frustrates me to have our technician pull a polypro frame for an AK socket and then have the thing wind up being significantly shorter than the flexible inner socket. At least I know when I laminate a rigid frame, it's going to fit over the flexible inner socket exactly when I'm done.
Also, with regards to circumferential shrinkage, is there a factor you can adjust for in fabrication, knowing that the shrinkage will occur? By this I mean something along the lines of putting a sock (# of ply?) over the flexible inner socket before pulling the polypro over it. We use the Fillauer shuttle lock a lot and so we often have BK sockets with a flexible inner socket and a polypro rigid outer socket. Once again, it's very frustrating to have a check socket fit really well, then mold a socket over the exact same cast, and then have the definitive socket be too small to the point where it's impossible to don!
Thanks for your help with this... any advice you can provide might help my professional life be far less stressful :)
Bill Lifford, C.P.
Lately it seems as though many of our facility's polypropylene sockets shrink quite a bit. Sometimes, though, the shrinkage seems to be circumferential and other times it seems to be longitudinal.
What are some methods we can use to control or reduce this shrinkage? I would rather not laminate everything, due to the dust created while grinding laminated sockets; however, it frustrates me to have our technician pull a polypro frame for an AK socket and then have the thing wind up being significantly shorter than the flexible inner socket. At least I know when I laminate a rigid frame, it's going to fit over the flexible inner socket exactly when I'm done.
Also, with regards to circumferential shrinkage, is there a factor you can adjust for in fabrication, knowing that the shrinkage will occur? By this I mean something along the lines of putting a sock (# of ply?) over the flexible inner socket before pulling the polypro over it. We use the Fillauer shuttle lock a lot and so we often have BK sockets with a flexible inner socket and a polypro rigid outer socket. Once again, it's very frustrating to have a check socket fit really well, then mold a socket over the exact same cast, and then have the definitive socket be too small to the point where it's impossible to don!
Thanks for your help with this... any advice you can provide might help my professional life be far less stressful :)
Bill Lifford, C.P.
Citation
William Lifford, “Polypropylene shrinkage - Prosthetic outer sockets/frames,” Digital Resource Foundation for Orthotics and Prosthetics, accessed November 26, 2024, https://library.drfop.org/items/show/221785.
