0
Technical Briefs

Knee Joint Secondary Motion Accuracy Improved by Quaternion-Based Optimizer With Bony Landmark Constraints

[+] Author and Article Information
Hongsheng Wang

Department of Mechanical Engineering and Engineering Science, Center for Biomedical Engineering Systems, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, NC 28223

Naiqaun (Nigel) Zheng1

Department of Mechanical Engineering and Engineering Science, Center for Biomedical Engineering Systems, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, NC 28223nzheng@uncc.edu

1

Corresponding author.

J Biomech Eng 132(12), 124502 (Nov 16, 2010) (6 pages) doi:10.1115/1.4002856 History: Received July 13, 2010; Revised October 13, 2010; Posted October 25, 2010; Published November 16, 2010; Online November 16, 2010

Skin marker-based motion analysis has been widely used in biomechanical studies and clinical applications. Unfortunately, the accuracy of knee joint secondary motions is largely limited by the nonrigidity nature of human body segments. Numerous studies have investigated the characteristics of soft tissue movement. Utilizing these characteristics, we may improve the accuracy of knee joint motion measurement. An optimizer was developed by incorporating the soft tissue movement patterns at special bony landmarks into constraint functions. Bony landmark constraints were assigned to the skin markers at femur epicondyles, tibial plateau edges, and tibial tuberosity in a motion analysis algorithm by limiting their allowed position space relative to the underlying bone. The rotation matrix was represented by quaternion, and the constrained optimization problem was solved by Fletcher’s version of the Levenberg–Marquardt optimization technique. The algorithm was validated by using motion data from both skin-based markers and bone-mounted markers attached to fresh cadavers. By comparing the results with the ground truth bone motion generated from the bone-mounted markers, the new algorithm had a significantly higher accuracy (root-mean-square (RMS) error: 0.7±0.1deg in axial rotation and 0.4±0.1deg in varus-valgus) in estimating the knee joint secondary rotations than algorithms without bony landmark constraints (RMS error: 1.7±0.4deg in axial rotation and 0.7±0.1deg in varus-valgus). Also, it predicts a more accurate medial-lateral translation (RMS error: 0.4±0.1mm) than the conventional techniques (RMS error: 1.2±0.2mm). The new algorithm, using bony landmark constrains, estimates more accurate secondary rotations and medial-lateral translation of the underlying bone.

FIGURES IN THIS ARTICLE
<>
Copyright © 2010 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

The moving spaces of skin markers at medial-lateral epicondyles (T10/T11), medial-lateral tibia plateau edges (S1/S2), and tibia tuberosity (S11). At T10, T11, S1, and S2 locations, only medial-lateral direction displacements are constrained. At S11 location, the displacement constraints are exerted on all three anatomical directions.

Grahic Jump Location
Figure 2

Protocol of skin marker attachment and bone pin marker fixation for collecting the motion data of two cadaver lower extremities

Grahic Jump Location
Figure 3

Definitions of knee joint rotations angle by a projection method

Grahic Jump Location
Figure 4

The true knee joint rotation angles generated from bone pins and the predicting angles, which were, respectively, calculated by three algorithms (LMS, BLC, and PCT)

Grahic Jump Location
Figure 5

The true knee joint translations (femur relative to tibia) generated from bone pins and the predicting translations, which were, respectively, calculated by three algorithms

Grahic Jump Location
Figure 6

The accuracy of BLC algorithm in predicting internal-external rotation, varus-valgus, and medial-lateral translation under different moving limits

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In