Day-to-Day Reliability of Two Different Models to Quantify Knee Kinematics in Subjects With Knee Osteoarthritis and Healthy Controls

2012 ◽  
Vol 28 (5) ◽  
pp. 560-567 ◽  
Author(s):  
Inga Krauss ◽  
Thomas Ukelo ◽  
Christoph Ziegler ◽  
Detlef Axmann ◽  
Stefan Grau ◽  
...  

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. Reliability was compared between a functional and a predictive gait model in subjects with knee osteoarthritis and healthy controls. Day-to-day consistency for sagittal plane variables was comparable between models and population groups. Transversal plane variables relative to joint excursion showed larger inconsistency for repeated measures, even for a more sophisticated biomechanical approach. In conclusion, the presented reliability data of sagittal plane kinematics should be used for a reasonable interpretation of results derived in clinical gait analysis. Variables of the transversal plane should not be used as long as sources of error are not sufficiently minimized.

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Hanna Ulbricht ◽  
Meijin Hou ◽  
Xiangbin Wang ◽  
Jian He ◽  
Yanxin Zhang

In gait analysis, the accuracy of knee joint angles and moments is critical for clinical decision-making. The purpose of this study was to determine the efficacy of two existing algorithms for knee joint axis correction under pathological conditions. Gait data from 20 healthy participants and 20 patients with knee osteoarthritis (OA) were collected using a motion capture system. An algorithm based on Principal Component Analysis (PCA) and a functional joint-based algorithm (FJA) were used to define the knee joint flexion axis. The results show that PCA decreased crosstalk for both groups, and FJA reduced crosstalk in patients with knee OA only. PCA decreased the range of motions of patients with knee OA in the direction of abduction/adduction significantly. There was a significant increase in the maximum knee flexion moment of patients with knee OA by FJA. The results indicate that both algorithms can efficiently reduce crosstalk for gait from patients with knee OA, which can further influence the results of knee joint angles and moments. We recommend that the correction algorithms be applied in clinical gait analysis with patients with knee OA.


2014 ◽  
Vol 30 (1) ◽  
pp. 104-112 ◽  
Author(s):  
Amber Collins ◽  
Troy Blackburn ◽  
Chris Olcott ◽  
Joanne M. Jordan ◽  
Bing Yu ◽  
...  

Extended use of knee sleeves in populations at risk for knee osteoarthritis progression has shown functional and quality of life benefits; however, additional comprehensive kinematic and kinetic analyses are needed to determine possible physical mechanisms of these benefits which may be due to the sleeve’s ability to enhance knee proprioception. A novel means of extending these enhancements may be through stochastic resonance stimulation. Our goal was to determine whether the use of a knee sleeve alone or combined with stochastic resonance electrical stimulation improves knee mechanics in knee osteoarthritis. Gait kinetics and kinematics were assessed in subjects with medial knee osteoarthritis when presented with four conditions: control1, no electrical stimulation/sleeve, 75% threshold stimulation/sleeve, and control2. An increase in knee flexion angle throughout stance and a decrease in flexion moment occurring immediately after initial contact were seen in the stimulation/sleeve and sleeve alone conditions; however, these treatment conditions did not affect the knee adduction angle and internal knee abduction moment during weight acceptance. No differences were found between the sleeve alone and the stochastic resonance with sleeve conditions. A knee sleeve can improve sagittal-plane knee kinematics and kinetics, although adding the current configuration of stochastic resonance did not enhance these effects.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Patrick Fuerst ◽  
Albert Gollhofer ◽  
Markus Wenning ◽  
Dominic Gehring

Abstract Background The application of ankle braces is an effective method for the prevention of recurrent ankle sprains. It has been proposed that the reduction of injury rates is based on the mechanical stiffness of the brace and on beneficial effects on proprioception and neuromuscular activation. Yet, how the neuromuscular system responds to the application of various types of ankle braces during highly dynamic injury-relevant movements is not well understood. Enhanced stability of the ankle joint seems especially important for people with chronic ankle instability. We therefore aimed to analyse the effects of a soft and a semi-rigid ankle brace on the execution of highly dynamic 180° turning movements in participants with and without chronic ankle instability. Methods Fifteen participants with functional ankle instability, 15 participants with functional and mechanical ankle instability and 15 healthy controls performed 180° turning movements in reaction to light signals in a cross-sectional descriptive laboratory study. Ankle joint kinematics and kinetics as well as neuromuscular activation of muscles surrounding the ankle joint were determined. Two-way repeated measures analyses of variance and post-hoc t-tests were calculated. Results Maximum ankle inversion angles and velocities were significantly reduced with the semi-rigid brace in comparison to the conditions without a brace and with the soft brace (p ≤ 0.006, d ≥ 0.303). Effect sizes of these reductions were larger in participants with chronic ankle instability than in healthy controls. Furthermore, peroneal activation levels decreased significantly with the semi-rigid brace in the 100 ms before and after ground contact. No statistically significant brace by group effects were found. Conclusions Based on these findings, we argue that people with ankle instability in particular seem to benefit from a semi-rigid ankle brace, which allows them to keep ankle inversion angles in a range that is comparable to values of healthy people. Lower ankle inversion angles and velocities with a semi-rigid brace may explain reduced injury incidences with brace application. The lack of effect of the soft brace indicates that the primary mechanism behind the reduction of inversion angles and velocities is the mechanical resistance of the brace in the frontal plane.


1998 ◽  
Vol 1 (1) ◽  
pp. 23-39
Author(s):  
Carter J. Kerk ◽  
Don B. Chaffin ◽  
W. Monroe Keyserling

The stability constraints of a two-dimensional static human force exertion capability model (2DHFEC) were evaluated with subjects of varying anthropometry and strength capabilities performing manual exertions. The biomechanical model comprehensively estimated human force exertion capability under sagittally symmetric static conditions using constraints from three classes: stability, joint muscle strength, and coefficient of friction. Experimental results showed the concept of stability must be considered with joint muscle strength capability and coefficient of friction in predicting hand force exertion capability. Information was gained concerning foot modeling parameters as they affect whole-body stability. Findings indicated that stability limits should be placed approximately 37 % the ankle joint center to the posterior-most point of the foot and 130 % the distance from the ankle joint center to the maximal medial protuberance (the ball of the foot). 2DHFEC provided improvements over existing models, especially where horizontal push/pull forces create balance concerns.


2021 ◽  
Author(s):  
Martin Huber ◽  
Matthew Eschbach ◽  
Kazem Kazerounian ◽  
Horea T. Ilies

Abstract Knee osteoarthritis (OA) is a disease that compromises the cartilage inside the knee joint, resulting in pain and impaired mobility. Bracing is a common treatment, however currently prescribed braces cannot treat bicompartmental knee OA, fail to consider the muscle weakness that typically accompanies the disease, and utilize hinges that restrict the knee's natural biomechanics. We have developed and evaluated a brace which addresses these shortcomings. This process has respected three principal design goals: reducing the load experienced across the entire knee joint, generating a supportive moment to aid the muscles in shock absorption, and interfering minimally with gait kinematics. Load reduction is achieved via the compression of medial and lateral leaf springs, and magnetorheological dampers provide the supportive moment during knee loading. A novel, personalized joint mechanism replaces a traditional hinge to reduce interference with knee kinematics. Using motion capture gait analysis, we evaluated the basic functionality of a prototype device. We calculated, via inverse dynamics analysis, the reaction forces at the knee joint and the moments generated by the leg muscles during gait. Comparing these values between braced and unbraced trials allowed us to evaluate the system's effectiveness. Kinematic measurements showed the extent to which the brace interfered with natural gait characteristics. Of the three design goals: a reduction in knee contact forces was demonstrated; increased shock absorption was observed, but not to statistical significance; and natural gait was largely preserved. The techniques presented in this paper could lead to improved OA treatment through patient-specific braces.


2018 ◽  
Vol 89 (6) ◽  
pp. 656-661 ◽  
Author(s):  
Evelina Pantzar-Castilla ◽  
Andrea Cereatti ◽  
Giulio Figari ◽  
Nicolò Valeri ◽  
Gabriele Paolini ◽  
...  

BJPsych Open ◽  
2021 ◽  
Vol 7 (4) ◽  
Author(s):  
Timea Sparding ◽  
Erik Joas ◽  
Caitlin Clements ◽  
Carl M. Sellgren ◽  
Erik Pålsson ◽  
...  

Background Cross-sectional studies have found impaired cognitive functioning in patients with bipolar disorder, but long-term longitudinal studies are scarce. Aims The aims of this study were to examine the 6-year longitudinal course of cognitive functioning in patients with bipolar disorder and healthy controls. Subsets of patients were examined to investigate possible differences in cognitive trajectories. Method Patients with bipolar I disorder (n = 44) or bipolar II disorder (n = 28) and healthy controls (n = 59) were tested with a comprehensive cognitive test battery at baseline and retested after 6 years. We conducted repeated measures ANCOVAs with group as a between-subject factor and tested the significance of group and time interaction. Results By and large, the change in cognitive functioning between baseline and follow-up did not differ significantly between participants with bipolar disorder and healthy controls. Comparing subsets of patients, for example those with bipolar I and II disorder and those with and without manic episodes during follow-up, did not reveal subgroups more vulnerable to cognitive decline. Conclusions Cognitive performance remained stable in patients with bipolar disorder over a 6-year period and evolved similarly to healthy controls. These findings argue against the notion of a general progressive decline in cognitive functioning in bipolar disorder.


2013 ◽  
Vol 10 (1) ◽  
pp. 525-545 ◽  
Author(s):  
Nenad Filipovic ◽  
Velibor Isailovic ◽  
Dalibor Nikolic ◽  
Aleksandar Peulic ◽  
Nikola Mijailovic ◽  
...  

In this study we modeled a patient specific 3D knee after anterior cruicate ligament (ACL) reconstruction. The purpose of the ACL reconstruction is to achieve stability in the entire range of motion of the knee and the establishment of the normal gait pattern. We present a new reconstruction technique that generates patient-specific 3D knee models from patient?s magnetic resonant images (MRIs). The motion of the ACL reconstruction patients is measured by OptiTrack system with six infrared cameras. Finite element model of bones, cartilage and meniscus is used for determination stress and strain distribution at different body postures during gait analysis. It was observed that the maximum effective von Mises stress distribution up to 8 MPa occurred during 30% of the gait cycle on the meniscus. The biomechanical model of the knee joint during gait analysis can provide insight into the underlying mechanisms of knee function after ACL reconstruction.


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