Day-to-day reliability of two different models to quantify knee kinematics in subjects with knee osteoarthritis and healthy controls.

Results from instrumented gait analysis vary between test situations. Subject characteristics and the biomechanical model can influence the total amount of variability. The purpose of this study was to quantify reliability of gait data in general, and with respect to the applied model, and investigated population group.

Comparison of distinctive gait variables using two different biomechanical models for knee joint kinematics in subjects with knee osteoarthritis and healthy controls.

Background: Gait analysis is an important instrument in clinical research and results should be objective. The purpose of this study was to quantify clinical outcomes of two biomechanical models with different anatomical coordinate systems and angle decomposition strategies for knee joint kinematics.

Methods: The study was designed to compare a functional approach and a predictive approach with a single comprehensive marker set.

Day-to-Day consistency of lower extremity kinematics during walking and running.

Before conclusions can be drawn with respect to the quality of adaptations in human gait, the day-to-day consistency of the variables of interest must be known. The present study estimated the day-to-day consistency of kinematic variables collected during barefoot walking and running. Sixteen healthy subjects performed two gait analysis sessions based on skin markers.

Transmissions within the tarsal gearbox.

Background: The dependence of the movements of the calcaneus, cuboid, navicular, and talus on each other have been described as the tarsal gearbox. To provide a basis of its modeling, data on transmissions between tarsal joint rotations within this gearbox are required. The feasibility of tibiocalcaneal rotations to predict tarsal joint rotations is of interest because a meaningful relation would allow the use of common motion analysis with skin markers to investigate rearfoot kinematics.

Does a specific MR imaging protocol with a supine-lying subject replicate tarsal kinematics seen during upright standing?

Magnetic resonance (MR) imaging is becoming increasingly important in the study of foot biomechanics. Specific devices have been constructed to load and position the foot while the subject is lying supine in the scanner. The present study examines the efficacy of such a newly developed device in replicating tarsal kinematics seen during the more commonly studied standing loading conditions.

Concurrent validity and intrasession reliability of the IDEEA accelerometry system for the quantification of spatiotemporal gait parameters.

The aim of this pilot study was to evaluate concurrent validity and intrasession reliability of the IDEEA (Minisun, Fresno, CA) accelerometry system (and associated software) with force plate measurements for spatiotemporal gait variables recorded during normal walking. Ten healthy individuals were asked to walk at a self-selected comfortable speed, over five multicomponent force plates embedded into the walkway floor. For each trial, spatiotemporal gait parameters (single support time, cadence, speed, step and stride length) obtained by the force plates were compared to those recorded by IDEEA.

Ground reaction forces on stairs. Part II: knee implant patients versus normals.

The goal of this study was to compare selected parameters of vertical ground reaction forces (GRF) of good outcome patients with different prosthesis designs with a matched control group during level walking, stair ascent and descent. Forty subjects, 29 with three main implant designs (including four subjects with a passive knee flexion restriction), and 11 healthy controls were measured with 8-10 repetitions. Vertical ground reaction forces were measured during two consecutive steps with force plates embedded in the walkway and the staircase.

Three-dimensional kinematics and kinetics of total knee arthroplasty during level walking using single plane video-fluoroscopy and force plates: a pilot study.

The goal of the study was to simultaneously obtain accurate kinematic and kinetic data from a total knee arthroplasty (TKA) during level walking, by coupling force plate data with the kinematics of TKA measured by a movable video-fluoroscopic system. Kinematic and kinetic information of a TKA is crucial for the improvement of implant designs and for the increased longevity of the implant components. Instrumented gait analysis, with skin mounted marker tracking and force plates, is a well-established method for the acquisition of kinematic and kinetic data of TKA in vivo and for non-invasive estimation of joint function.

Biomechanical background and clinical observations of rotational malalignment in TKA: literature review and consequences.

Malalignment, in particular femoral component malrotation, is a commonly accepted failure mode in total knee arthroplasty. The general objective of this paper is twofold: firstly, it accentuates clinical observations of the effects of rotational malalignment in total knee arthroplasty. Secondly, it discusses the relevant parameters of existing knee joint models with regards to rotational malalignment and its biomechanical background, thereby setting a basis for future studies.

Ground reaction forces on stairs: effects of stair inclination and age.

The goals of the study were to compare data of vertical ground reaction force (GRF) parameters during level walking, stair ascent and descent on three different stair inclinations and three different age groups. Twenty healthy subjects of three age groups (young 33.7 years; middle 63.