A marker-free method to estimate joint centre of rotation by video image processing

Area of Science:

• Biomechanics
• Medical Imaging
• Computer Vision

Background:

• Accurate measurement of joint rotation is crucial for human locomotion analysis.
• Existing marker-based methods can be invasive or prone to marker displacement.
• A marker-free approach could offer a more practical and less intrusive solution.

Purpose of the Study:

• To develop and validate a marker-free image processing method for estimating the 2-D center of rotation of rigid segments.
• To compare the accuracy of the marker-free method against a marker-based approach.
• To extend the algorithm for analyzing two rigid segments, applicable to human locomotion.

Main Methods:

• Utilized a novel algorithm based on binary region moment features for marker-free measurement.
• Implemented and compared a marker-based method with two marker localization calculation variations.
• Extended the marker-free algorithm to accommodate analysis of two rigid segments.

Main Results:

• The marker-free method provides numerical estimation of the 2-D center of rotation.
• The algorithm's accuracy was validated against in vivo radiological measurements in humans.
• The method was successfully extended to handle two rigid segments.

Conclusions:

• The developed marker-free video measurement and image processing method is a viable tool for estimating the 2-D center of rotation.
• This technique holds significant potential for applications in human locomotion analysis, specifically for hip joint biomechanics.
• Further validation and application in clinical settings are warranted.