the subject of geometry and proportions has been regarded as an issue which has a close relationship with architecture. since the entire universe, living beings and the human geometry can be seen clearly, that’s why our unconscious essence has accustomed to these proportions whereby reflection of this mentality can be seen in the architect’s hands and thought in the architecture. it can witness...

When humans hop in place or run forward, leg stiffness is increased to offset reductions in surface stiffness, allowing the global kinematics and mechanics to remain the same on all surfaces. The purpose of the present study was to determine the mechanism for adjusting leg stiffness. Seven subjects hopped in place on surfaces of different stiffnesses (23-35,000 kN/m) while force platform, kinem...

Validated computational knee simulations are valuable tools for design phase development of knee replacement devices. Recently, a dynamic finite element (FE) model of the Kansas knee simulator was kinematically validated during gait and deep flexion cycles. In order to operate the computational simulator in the same manner as the experiment, a proportional-integral-derivative (PID) controller w...

Knowledge about the knee cartilage deformation ratio as well as the knee cartilage stress distribution is of particular importance in clinical studies due to the fact that these represent some of the basic indicators of cartilage state and that they also provide information about joint cartilage wear so medical doctors can predict when it is necessary to perform surgery on a patient. In this re...

Moment arms represent a muscle's ability to generate a moment about a joint for a given muscle force. The goal of this study was to develop a method to measure muscle moment arms in vivo over a large range of motion using real-time magnetic resonance (MR) imaging. Rectus femoris muscle-tendon lengths and knee joint angles of healthy subjects (N = 4) were measured during dynamic knee joint flexi...

Introduction The load response of a knee joint is dominated by the mechanical properties of articular cartilage, which consists of proteoglycan matrix, collagen fiber network and a fluid. The interplay of these three constituents determines the load support of articular cartilage in the joint. Finite element analysis has been widely applied to study joint mechanics. Accurate knee contact geomet...

This paper reviews the recent advancements in computational modelling of lubrication hip and knee joint replacements, especially those concerning Professor Duncan Dowson’s contribution. The review starts with development five key parameters that appeared pioneered Hamrock–Dowson formula. Then, theory approaches for mixed which artificial replacements operate are reviewed. We also discuss curren...

Knee injuries are a common form of disability, but many can be treated using surgery. The minimally invasive approach of arthroscopy means faster recover times for the patient than when using open surgery, but the skills required by the surgeon are radically different. Although a number of arthroscopic training techniques are available all have problems either with cost, maintenance or availabi...

+MR Dressler, S Swope, J Tikka, C Hardaker, M Heldreth, T Render +DePuy Orthopaedics Research, Warsaw, IN [email protected] INTRODUCTION An estimated 46 million Americans suffer from osteoarthritis [1]. As tissue engineered treatments and other options remain on the horizon, total knee arthroplasty (TKA) continues to be an efficacious solution for severe osteoarthritis and has been increasin...

OBJECTIVE This work aimed to assess tibial rotations, meniscal movements, and morphological changes during knee flexion and extension using kinematic magnetic resonance imaging (MRI). METHODS Thirty volunteers with healthy knees were examined using kinematic MRI. The knees were imaged in the transverse plane with flexion and extension angles from 0° to 40° and 40° to 0°, respectively. The tib...