Proximal placement of lateral thigh skin markers reduces soft tissue artefact during normal gait using the Conventional Gait Model

Cockcroft, J; Louw, Q; Baker, RJ

Abstract

A primary source of measurement error in gait analysis is soft tissue artefact. Hip and knee angle measurements, used regularly to guide clinical decisions, are particularly affected due to pervasive soft tissue on the femur. However, despite several studies of thigh marker artefact it remains unclear how lateral thigh marker height affects results using the popular Plug-in Gait model. We compared Plug-in Gait hip and knee joint angles for ten healthy subjects estimated using a proximal- and distal-third thigh marker placement and found significant differences. Relative to the distal marker, the proximal marker produced 37% less varus-valgus range and 50% less hip rotation range, suggesting that it produced less soft-tissue artefact in knee axis estimates. Knee flexion was also significantly affected due to knee centre displacement. Based on an analysis of the Plug-in Gait knee axis definition and two different numerical optimization of the thigh rotation offset parameter, we show that the proximal marker reduced sensitivity to soft-tissue artefact by decreasing collinearity between the points defining the femoral frontal plane and reducing anteroposterior movement between the knee and thigh markers. This study demonstrates that Plug-in Gait thigh marker height can have a considerable influence on outcomes used for clinical decision-making.

Citation

Cockcroft, J., Louw, Q., & Baker, R. (2016). Proximal placement of lateral thigh skin markers reduces soft tissue artefact during normal gait using the Conventional Gait Model. Computer Methods in Biomechanics and Biomedical Engineering, 19(14), 1497-1504. https://doi.org/10.1080/10255842.2016.1157865

• Journal Article Type: Article
• Acceptance Date: Feb 21, 2016
• Online Publication Date: Mar 1, 2016
• Publication Date: Mar 1, 2016
• Deposit Date: Apr 11, 2016
• Publicly Available Date: Mar 5, 2017
• Journal: Computer Methods in Biomechanics and Biomedical Engineering
• Print ISSN: 1025-5842
• Electronic ISSN: 1476-8259
• Publisher: Taylor and Francis
• Volume: 19
• Issue: 14
• Pages: 1497-1504
• DOI: https://doi.org/10.1080/10255842.2016.1157865
• Publisher URL: http://dx.doi.org/10.1080/10255842.2016.1157865
• Related Public URLs: http://www.tandfonline.com/toc/gcmb20/current