Observational Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Jun 18, 2016; 7(6): 383-391
Published online Jun 18, 2016. doi: 10.5312/wjo.v7.i6.383
Quantifying prosthetic gait deviation using simple outcome measures
Lauren Kark, Ross Odell, Andrew S McIntosh, Anne Simmons
Lauren Kark, Ross Odell, Anne Simmons, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia
Andrew S McIntosh, Australian Centre for Research into Injury in Sport and its Prevention, Federation University, Ballarat, Victoria 3350, Australia
Author contributions: All authors contributed equally to the design of the study; Kark L collected and analysed the data, and prepared the initial manuscript; data analysis was performed in collaboration with Odell R; all authors revised the article.
Institutional review board statement: This study received approval from the University of New South Wales Human Research Ethics Committee (approval No.: HREC07247).
Informed consent statement: All study participants provided informed written consent prior to study enrolment.
Conflict-of-interest statement: The authors report no conflicts of interest.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Lauren Kark, Graduate School of Biomedical Engineering, University of New South Wales, Samuels Building (F25), Gate 11 Botany Street, Randwick, Sydney, NSW 2052, Australia. lauren.kark@unsw.edu.au
Telephone: +61-2-93850560 Fax: +61-2-96632108
Received: January 29, 2016
Peer-review started: February 1, 2016
First decision: March 25, 2016
Revised: April 12, 2016
Accepted: May 7, 2016
Article in press: May 9, 2016
Published online: June 18, 2016

AIM: To develop a subset of simple outcome measures to quantify prosthetic gait deviation without needing three-dimensional gait analysis (3DGA).

METHODS: Eight unilateral, transfemoral amputees and 12 unilateral, transtibial amputees were recruited. Twenty-eight able-bodied controls were recruited. All participants underwent 3DGA, the timed-up-and-go test and the six-minute walk test (6MWT). The lower-limb amputees also completed the Prosthesis Evaluation Questionnaire. Results from 3DGA were summarised using the gait deviation index (GDI), which was subsequently regressed, using stepwise regression, against the other measures.

RESULTS: Step-length (SL), self-selected walking speed (SSWS) and the distance walked during the 6MWT (6MWD) were significantly correlated with GDI. The 6MWD was the strongest, single predictor of the GDI, followed by SL and SSWS. The predictive ability of the regression equations were improved following inclusion of self-report data related to mobility and prosthetic utility.

CONCLUSION: This study offers a practicable alternative to quantifying kinematic deviation without the need to conduct complete 3DGA.

Keywords: Gait deviation, Prosthesis, Amputation, Functional outcomes, Regression, Receiver operating characteristic curve

Core tip: The number of available outcome measures and multi-dimensionality of functional status complicate appropriate selection. This study assists clinicians in choosing apposite measures by exploring the relationship between various measures and demonstrating that often expensive and unavailable measures can be estimated using a combination of readily available self-report and performance-based measures.