STATISTICAL MODELING OF KNEE JOINT GEAR RATIOS

Abstract

Subject of Research. The paper presents a new approach to the analysis of experimental data on walking. It involves the application of gear ratio statistics. The research is based on the experimental data on flexion-extension-rotation movement of knee joint that has been obtained in the laboratory of kinesiology and biomechanics of Tartu University, Estonia. Methods. Angular velocities have been calculated for each of the motion data phases. Temporal values of angular velocity sign changes have been represented as a random process. The role of the Poisson distribution for modeling distribution of transition points through zero has been considered. Correlation functions and spectral densities of these processes have been created. The role of uniform distribution in the estimation of gear ratios has been described. The ontribution of cruciate ligaments in the movement transmission has been studied. Main Results. The average values and variance of gear ratios have been calculated as a result of d ata processing by Poisson and Fischer statistics. An elastic transmission mechanism model for flexion-extension-rotation of knee joint movement using the gear ratio and features of helical anisotropy in application to the mechanics of cruciate ligaments has been proposed. Practical Relevance. The work is aimed at the searh for solutions to modernization problems of elastic actuators used in design of knee orthoses.

Keywords

• knee joint
• flexion-extension
• rotation
• statistics
• gear ratios
• crucial ligaments