Faculty Collaboration Database

The instantaneous axis of rotation (IAOR) of the foot and ankle: a self-determining system with implications for rehabilitation medicine application. IEEE Trans Neural Syst Rehabil Eng 2002 Dec;10(4):232-8

Date

03/04/2003

Pubmed ID

12611361

DOI

10.1109/TNSRE.2002.806843

Scopus ID

2-s2.0-0036997381 (requires institutional sign-in at Scopus site)   14 Citations

Abstract

A noninvasive method for determining the instantaneous axis of rotation (IAOR) of the foot and ankle during human ambulation has been developed. The algorithm uses three-dimensional (3-D) external marker trajectories to describe the IAOR of the calcaneus with respect to the tibia. Multiple optimization techniques were used to fit a plane and a sphere to the marker trajectories, with the constraint that the center of the sphere lie on the plane. The IAOR was defined perpendicular to the plane and passed through the center of the sphere. The results from validation procedures have demonstrated the applicability of the method. Experimental IAOR data acquired from normal adult subjects indicated the ability to track the IAOR during gait. This self-determining system for locating a patient's foot and ankle IAOR during gait may benefit rehabilitation applications in pedorthic and prosthetic design, surgical and nonsurgical treatment, and rehabilitative approaches to suprasegmental functional accommodation.

Author List

Demarais DM, Bachschmidt RA, Harris GF

Authors

Gerald F. Harris Emeritus Professor in the Orthopaedic Surgery department at Medical College of Wisconsin
Gerald Harris PhD Director in the Orthopaedic Research Engineering Center (OREC) department at Marquette University

MESH terms used to index this publication - Major topics in bold

Aged
Algorithms
Ankle
Ankle Joint
Calcaneus
Computer Simulation
Female
Foot
Foot Bones
Gait
Humans
Imaging, Three-Dimensional
Middle Aged
Movement
Rehabilitation
Reproducibility of Results
Rotation
Sensitivity and Specificity
Tibia
Walking