Novel computational approaches characterizing knee physiotherapy

Design of Titanium Alloy Femoral Stem Cellular Structure for Stress Shielding and Stem Stability: Computational Analysis

The main objective of this study is to design titanium alloy femoral stems with cubic porous structures that will be able to reduce stress shielding and promote stem stability. These porous structure designs were introduced into titanium alloy femoral stems as homogeneous and functionally graded porous structures. First, the cubic cellular structures were simulated under compressive loading to measure the yield and modulus of elasticity for various porosity ranges. Based on the selected porosity range, fifteen different arrangements of radial geometrical functionally graded (FG) designs were developed with average porosities of 30, 50, and 70% respectively. Finite element models were developed with physiological loads presenting three different walking speeds (1, 3, and 5 km/h), where the average human body weight was assumed. Stresses at the bone Gruen zones were measured to check the percentage of stress transfer to the bone for each porous stem design and were compared with the bulk stem. Several FG stem designs were shortlisted for further investigation as candidates for hip implants.

Freedom in Osteoarthritis of the Knee

The first peak of the external knee abduction moment (KAM) is often used as a surrogate measure of the medial compartment loading and has been correlated with pain and progression of knee osteoarthritis (OA). As a result, reducing the KAM is often the target of conservative interventions. OA should be considered as a “Whole Person” disease, including ecological psychosocial aspects. Scientists have developed gait alteration strategies to reduce the KAM. They attempted to force into a new position any particular part without reference to the pattern of the whole. We propose an alternative approach: in the vicinity of a special configuration of the knee, some or all of the components of the knee become overloaded. This study has shown that when six lines $1′,$2′,$3′,$4′,$5′,$6′ are so situated that forces acting along them equilibrate when applied to one degree of freedom, 1° F knee, a certain determinant vanishes. We wish to define the six lines as the knee complex in involution by virtue of some constraint upon the knee.

A Deterministic Model of Human Motion Based on Algebraic Techniques and a Sensor Network to Simulate Shoulder Kinematics

Limiting the quantitative characterization of ambulatory mobility to only the two-dimensional sagittal plane through the investigation of key kinematic parameters, may still inform scientists and bioengineers of critical elements of joint locomotion. This paper presents the initial validation of a deterministic biomechanical gait model that was derived from an inverse kinematic analysis of three-dimensional upper extremity movement. Algebraic methods were applied to generate shoulder flexion and extension angles during a single gait cycle during normal walking. The direct kinematic measurements from a motion capture system were analyzed and compared to the predicted measurements from the algebraic model for eight healthy, human subjects. The predicted results over all subjects varied from the actual joint angle measurements with a nominal amount of mean error (23%), while correlations were quite strong (mean R2 = 0.97). These findings indicate the potential value of deterministic modeling with algebraic techniques as an alternative to existing methods.