Parameters Estimation for the Spherical Model of the Human Knee Joint Using Vector Method

Abstract

Position and displacement analysis of a spherical model of a human knee joint using the vector method was presented. Sensitivity analysis and parameter estimation were performed using the evolutionary algorithm method. Computer simulations for the mechanism with estimated parameters proved the effectiveness of the prepared software. The method itself can be useful when solving problems concerning the displacement and loads analysis in the knee joint.

Design and Characterization of a Novel Knee Articulation Mechanism

“…On the one hand, it is a simplified model of the human knee mechanism concentrating on the main flexion/extension movement just in the sagittal plane. In this way it constitutes a simplification of already developed complicated and complex models taking into consideration the 3D movement, meniscus, patella (Ciszkiewicz and Knapczyk [21]) and other elements that are based mainly on bone surface cooperation (Ciszkiewicz and Knapczyk [2]). On the other hand, the proposed solution is an advance with respect to the other existing mechanisms, since it takes into consideration the complexity (roll and slide) of flexion/extension movement.…”

“…Nowadays, this knowledge is common and orthotic devices use various mechanisms to reproduce the approximately proper motion. The well-known knee model based on a crossed four-bar mechanism is partially derived from the knee's anatomy, particularly the anterior and posterior cruciate ligaments behaviour may be simplified by two crossed bars ( Fig.2) (Ciszkiewicz and Knapczyk [2]). …”

Parameters Estimation For A Patellofemoral Joint Of A Human Knee Using A Vector Method

“…The substitute mechanism for the patella part of the knee joint ( Fig.1b) can be described with one tetrahedron presented in Fig.2a. In order to obtain the position of the patella reference frame with respect to the tibia reference frame a unit vector o 54 e describing the patella orientation can be determined using the formula for finding one of three unit vectors, when two unit vectors and two dot products of each these vectors with the unknown unit b) a) vector are known (Ciszkiewicz and Knapczyk, 2014…”

“…from the femur reference frame {x f y f z f } to the tibia reference frame {x t y t z t } obtained from the spherical model (Ciszkiewicz and Knapczyk, 2014). The position vectors of the points B 5 and B 6 in the tibia reference frame can be computed as follows…”

Numerical analysis of stress distribution generated in spherical polyethylene inserts by knee joint endoprotheses’ sleds

“…Low value of Young modulus in new titanium alloys can assure lower value of generated stresses in polyethylene inserts cooperating with metal sleds as well as better performance between stem and bone [11][12][13][14][15] .…”