gms | German Medical Science

15th Congress of the European Forum for Research in Rehabilitation (EFRR)

15.04. - 17.04.2019, Berlin

Establishing K-levels and prescribing transtibial prostheses using walking tests

Meeting Abstract

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  • corresponding author presenting/speaker Gaj Vidmar - University Rehabilitation Institute, Ljubljana, Slovenia
  • Helena Burger - University Rehabilitation Institute, Ljubljana, Slovenia
  • Neža Majdič - University Rehabilitation Institute, Ljubljana, Slovenia

15th Congress of the European Forum for Research in Rehabilitation (EFRR). Berlin, 15.-17.04.2019. Düsseldorf: German Medical Science GMS Publishing House; 2019. Doc038

doi: 10.3205/19efrr038, urn:nbn:de:0183-19efrr0380

Published: April 16, 2019

© 2019 Vidmar et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at



Background: Rehabilitation programs after amputation often include fitting and prescribing a prosthesis, but prescriptions vary significantly under relatively similar circumstances. The US Medicare Functional Classification Level (K-level) is a scale for describing functional abilities of persons who had undergone lower-limb amputation (0=no ability or potential to ambulate, to 4=prosthetic demands of a child, active adult or athlete). Different outcome measures are used to assess K-level, including the Six-Minute Walk Test (6MWT) and One-Leg Standing Test (OLST).

Aim: We attempted to predict appropriate K-level of transtibial prosthesis users based on 6MWT and OLST on prosthesis.

Method: Patients who had been rehabilitated and fitted with transtibial prosthesis at the University Rehabilitation Institute in Ljubljana in 2014 were included in a retrospective audit. 6MWT and OLST results were analysed to obtain K-level classification rules using ROC curve analysis, linear discriminant analysis, classification trees and ordinal logistic regression.

Results/findings: Of the 120 patients (aged 39-90, mean 67 years; 79% men), 8 beloged to K1 level, 94 to K2 and 18 to K3; 61 could not stand on the prosthesis, 8 stood on it for 1s, and 51 stood on it for 2s or more. A simple classification rule based only on 6MWT (130m threshold for K2 vs. K1, 385m for K3 vs. K1 or 2) yielded estimated sensitivity and specificity close to 90%. More sophisticated statistical approaches yield substantially similar and equivalently accurate results.

Discussion and conclusions: 6MWT and OLST could be used as predictors for transtibial prosthesis prescription in clinical practice. No two amputees have the exactly same general physical status, stump characteristics and occupational problems, so others factor must also be taken into account when prescribing a prosthesis.