purpose of this project is to
assess fabrication quality of
prosthetic sockets and
positive models, and to
determine to what degree
too large a socket impacts
the health and quality of life
of individuals with
transtibial amputation using
Findings to date: We found considerable variability in the quality
of computer-manufactured sockets [#5] and models [#3] made by
the central fabrication industry in prosthetics. Some central
fabrication facilities (~40%) consistently demonstrated very low
manufacturing error while others were less consistent. These
findings led us to publish an evaluation strategy for central
fabrication facilities to test their equipment [#2]. The strategy
may also be useful to companies who manufature fabrication
equipment as well as clinics who have fabrication facilities in
house. We also offer testing services to clinics, companies, and
individuals as part of our laboratory's services through a
not-for-profit cost center. The intent is to provide a detailed
report of the manufacturing quality of the models/sockets made
using the computer-manufacturing suite of equipment.
We are currently investigating how much size and shaping error
cause a clinically detectable change in prosthetic fit. If we
discover clear metrics that correlate with the user's quality of fit
then those metrics may be useful towards creating outcome
assessment criteria for clinical care.
We gratefully acknowledge funding from the National Institutes
of Health, R01HD-069387.
Advanced Socket Fabrication
#1. Sanders JE, Severance MR, Allyn KJ. Computer-socket manufacturing error: How
much before it is clinically apparent? J Rehabil Res Dev. 2012; 49(4):567-582. PMID.
#2. Sanders JE, Severance MR. Assessment technique for computer-aided manufactured
sockets. J Rehabil Res Dev. 2011; 48(7): 763-74. PMID: 21938663.
#3. Sanders JE, Severance MR, Myers TR, Ciol MA. Central fabrication: carved positive
assessment. Prosthet Orthot Int. 2011 Mar; 35(1): 81-9. PMID: 21515893.
#4. Sanders JE, Severance MR. Measuring foam model shapes with a contact digitizer.
Prosthet Orthot Int. 2011 Jun; 35(2): 242-5. PMID:21515900.
#5. Sanders JE, Rogers EL, Sorenson EA, Lee GS, Abrahamson DC. CAD/CAM transtibial
prosthetic sockets from central fabrication facilities: how accurate are they? J Rehabil Res
Dev. 2007; 44(3): 395-405. PMID:18247236.
#6. Zachariah SG, Sorenson E, Sanders JE. A method for aligning trans-tibial residual
limb shapes so as to identify regions of shape change. IEEE Trans Neural Syst Rehabil
Eng. 2005 Dec; 13(4): 551-7. PMID:16425837.
#7. Sanders JE, Mitchell SB, Zachariah SG, Wu K. A digitizer with exceptional accuracy
for use in prosthetics research: a technical note. J Rehabil Res Dev. 2003 Mar-Apr; 40(2):
Recent meetings presentations:
A. CAD/CAM sockets: clinical assessment of fit vs. socket shape error. American Academy
of Orthotists and Prosthetists 37th Academy Annual Meeting and Scientific Symposium,
Orlando, Florida, 2011
B. How accurate are carved positives made by central fabrication facilities? Thranhardt
Award Winner, American Academy of Orthotists and Prosthetists 36th Academy Annual
Meeting and Scientific Symposium, Chicago, Illinois, 2010