Amplitude and Phasing of Trunk Motion is Critical for the Efficacy of Gait Training Aimed at Reducing Ambulatory Loads at the Knee

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Annegret Mündermann ◽  
Lars Mündermann ◽  
Thomas P. Andriacchi
Keyword(s):  
Gait Training ◽  
Knee Adduction Moment ◽  
Heel Strike ◽  
Trunk Motion ◽  
Training Interventions ◽  
Optimal Intervention ◽  
Peak Knee ◽  
Trunk Sway ◽  
Analysis System ◽  
The Relationship

The purpose of this study was to determine the contribution of changes in amplitude and phasing of medio-lateral trunk sway to a change in the knee adduction moment when walking with increased medio-lateral trunk sway. Kinematic and kinetic data of walking trials with normal and with increased trunk sway were collected for 19 healthy volunteers using a standard motion analysis system. The relationship between the change in first peak knee adduction moment (ΔKAM) and change in trunk sway amplitude (ΔSA; difference between maximum contralateral trunk lean and maximum ipsilateral trunk lean) and phasing (SP; time of heel-strike relative to time of maximum contralateral and time of maximum ipsilateral trunk lean) was determined using nonlinear regression analysis. On average, subjects increased their SA by 9.7 ± 3.6 deg (P < 0.001) with an average SP of 98.8 ± 88.8 ms resulting in an average reduction in the first peak knee adduction moment of −55.2 ± 30.3% (P < 0.001). 64.3% of variability in change in peak knee adduction moment with the increased trunk sway condition was explained by both differences in SA and SP, and the relationship among these parameters was described by the regression equation ΔKAM = 27.220−4.128 · ΔSA-64.785 · cos(SP). Hence, not only the amplitude but also the phasing of trunk motion is critical. Not only lower limb movement but also lumbar and thoracic lateral flexion should be considered in the decision making process for an optimal intervention aimed at reducing the load on the medial compartment of the knee during walking. However, these promising findings originated from studies on healthy subjects and their relevance for gait training interventions in patients with presumably painful knee osteoarthritis remains to be determined.

scholarly journals The Influence of Radiographic Severity on the Relationship between Muscle Strength and Joint Loading in Obese Knee Osteoarthritis Patients

Arthritis ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Jens Aaboe ◽  
Henning Bliddal ◽  
Tine Alkjaer ◽  
Mikael Boesen ◽  
Marius Henriksen
Keyword(s):  
Muscle Strength ◽  
Knee Osteoarthritis ◽  
Knee Adduction Moment ◽  
Joint Loading ◽  
Cross Sectional ◽  
Radiographic Severity ◽  
Peak Knee ◽  
The Relationship ◽  
Knee Joint Loading ◽  
External Knee Adduction Moment

Objective. To investigate the relationship between knee muscle strength and the external knee adduction moment during walking in obese knee osteoarthritis patients and whether disease severity influences this relationship. Methods. This cross-sectional study included 136 elderly obese (BMI>30) adults with predominant medial knee osteoarthritis. Muscle strength, standing radiographic severity as measured by the Kellgren and Lawrence scale, and the peak external knee adduction moment were measured at self-selected walking speed. Results. According to radiographic severity, patients were classified as “less severe” (KL 1-2, N=73) or “severe” (KL 3-4, N=63). A significant positive association was demonstrated between the peak knee adduction moment and hamstring muscle strength in the whole cohort (P=.047). However, disease severity did not influence the relationship between muscle strength and dynamic medial knee joint loading. Severe patients had higher peak knee adduction moment and more varus malalignment (P<.001). Conclusion. Higher hamstring muscle strength relates to higher estimates of dynamic knee joint loading in the medial compartment. No such relationship existed for quadriceps muscle strength. Although cross sectional, the results suggest that hamstrings function should receive increased attention in future studies and treatments that aim at halting disease progression.

Condylar Contact During Normal Walking and Lateral Trunk Sway Gait: an EMG-Driven Modeling Approach to Estimate Articular Loading

2010 ◽  
Author(s):  
Kurt Manal ◽  
Bernardo Innocenti ◽  
Luc Labey ◽  
Thomas S. Buchanan
Keyword(s):  
Contact Force ◽  
Lateral Compartment ◽  
Knee Adduction Moment ◽  
Activation Patterns ◽  
Modeling Approach ◽  
Antagonist Muscles ◽  
Subject Specific ◽  
Trunk Sway ◽  
Hump Pattern ◽  
The Relationship

The knee adduction moment has a characteristic double hump pattern with the first peak generally larger than the second. Recently, Mundermann showed that walking with a lateral trunk sway can reduce the 1st peak moment [1]. One might expect from this finding that there would be a decrease in medial compartment loading. This however may be too simplistic a view. Fregly et al. showed that a decrease in knee adduction moment does not guarantee a decrease in medial contact [2]. Moreover, the relationship between net joint moments and loading is not straightforward, especially when agonist/antagonist muscles are co-activated as occurs in patients with pathology. Computational methods can benefit by accounting for subject specific neuromuscular activation patterns while taking into account subject specific dynamics when predicting articular loading. In this paper we outline our EMG-driven modeling approach to predict articular loading during trunk sway for a patient with a force measuring instrumented knee implant. We hypothesized that walking with a lateral trunk sway would: (a) decrease medial contact force, and (b) increase contact force in the lateral compartment.

Gait Modification via Verbal Instruction and an Active Feedback System to Reduce Peak Knee Adduction Moment

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Ariel V. Dowling ◽  
David S. Fisher ◽  
Thomas P. Andriacchi
Keyword(s):  
Weight Bearing ◽  
Feedback System ◽  
Gait Training ◽  
Knee Adduction Moment ◽  
Verbal Instruction ◽  
Medial Side ◽  
Peak Knee ◽  
Weight Shift ◽  
Active Feedback ◽  
Gait Modification

The purpose of this study was to introduce a simple gait training method using real-time gait modification to reduce the peak knee adduction moment during walking by producing a subtle weight bearing shift to the medial side of the foot. The hypothesis of this study was that this weight shift could be achieved via either verbal instruction or an active feedback system, and that the weight shift would result in a reduction in the first peak knee adduction moment compared with the control tests. Nine individuals were tested during walking using two intervention methods: verbal instruction and an active feedback system placed on the right shoe. The first peak of the knee adduction moment for each condition was assessed using a motion capture system and force plate. The active feedback system significantly reduced (14.2%) the peak knee adduction moment relative to the control. This study demonstrated that a subtle weight bearing shift to the medial side of the foot produced with an active feedback system during walking reduced the first peak of the knee adduction moment and suggests the potential application of this method to slow the rate of progression of medial compartment knee osteoarthritis.

scholarly journals Is Hip Muscle Strength Associated with Dynamic Knee Valgus in a Healthy Adult Population? A Systematic Review

2021 ◽  
Vol 18 (14) ◽  
pp. 7669
Author(s):  
Ali Mohammed Alzahrani ◽  
Msaad Alzhrani ◽  
Saeed Nasser Alshahrani ◽  
Wael Alghamdi ◽  
Mazen Alqahtani ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Adult Population ◽  
Knee Valgus ◽  
Journal Articles ◽  
Hip Muscle ◽  
Hip Abductor ◽  
Hip Muscles ◽  
Analysis System ◽  
The Relationship ◽  
External Rotator

This study aimed to systematically review research investigating the association between hip muscle strength and dynamic knee valgus (DKV). Four databases (MEDLINE, PubMed, CINAHL, and SPORTDiscus) were searched for journal articles published from inception to October 2020. Seven studies investigating the association between hip muscle strength and DKV using a two-dimensional motion analysis system in healthy adults were included. The relationship between hip abductor muscle strength and DKV was negatively correlated in two studies, positively correlated in two studies, and not correlated in three studies. The DKV was associated with reduced hip extensor muscle strength in two studies and reduced hip external rotator muscle strength in two studies, while no correlation was found in three and five studies for each muscle group, respectively. The relationship between hip muscle strength, including abductors, extensors, and external rotators and DKV is conflicting. Considering the current literature limitations and variable methodological approaches used among studies, the clinical relevance of such findings should be interpreted cautiously. Therefore, future studies are recommended to measure the eccentric strength of hip muscles, resembling muscular movement during landing. Furthermore, high-demand and sufficiently challenging functional tasks revealing lower limb kinematic differences, such as cutting and jumping tasks, are recommended for measuring the DKV.

scholarly journals Kinematic Comparison between Medially Congruent and Posterior-Stabilized Third-Generation TKA Designs

2021 ◽  
Vol 6 (1) ◽  
pp. 27
Author(s):  
Stefano Ghirardelli ◽  
Jessica L. Asay ◽  
Erika A. Leonardi ◽  
Tommaso Amoroso ◽  
Thomas P. Andriacchi ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Knee Kinematics ◽  
Primary Total Knee Arthroplasty ◽  
Flexion Angle ◽  
Heel Strike ◽  
Third Generation ◽  
Knee Flexion Angle ◽  
Posterior Stabilized ◽  
Rotational Angle ◽  
Peak Knee

Background: This study compares knee kinematics in two groups of patients who have undergone primary total knee arthroplasty (TKA) using two different modern designs: medially congruent (MC) and posterior-stabilized (PS). The aim of the study is to demonstrate only minimal differences between the groups. Methods: Ten TKA patients (4 PS, 6 MC) with successful clinical outcomes were evaluated through 3D knee kinematics analysis performed using a multicamera optoelectronic system and a force platform. Extracted kinematic data included knee flexion angle at heel-strike (KFH), peak midstance knee flexion angle (MSKFA), maximum and minimum knee adduction angle (KAA), and knee rotational angle at heel-strike. Data were compared with a group of healthy controls. Results: There were no differences in preferred walking speed between MC and PS groups, but we found consistent differences in knee function. At heel-strike, the knee tended to be more flexed in the PS group compared to the MC group; the MSKFA tended to be higher in the PS group compared to the MC group. There was a significant fluctuation in KAA during the swing phase in the PS group compared to the MC group, PS patients showed a higher peak knee flexion moment compared to MC patients, and the PS group had significantly less peak internal rotation moments than the MC group. Conclusions: Modern, third-generation TKA designs failed to reproduce normal knee kinematics. MC knees tended to reproduce a more natural kinematic pattern at heel-strike and during axial rotation, while PS knees showed better kinematics during mid-flexion.

Effect of Vibration on Rapeseed Header Loss and Optimization of Header Frame

2021 ◽  
Vol 64 (4) ◽  
pp. 1247-1258
Author(s):  
Yang Li ◽  
Lizhang Xu ◽  
Zhipeng Gao ◽  
En Lu ◽  
Yaoming Li
Keyword(s):  
Modal Analysis ◽  
Engine Speed ◽  
Vibration Measurement ◽  
List Type ◽  
Positive Correlation ◽  
Combine Harvester ◽  
Analysis System ◽  
Combine Harvesters ◽  
Relationship Of ◽  
The Relationship

HighlightsThe relationship of vibration and header loss was studied by multi-point vibration measurement and loss collection test.There was an approximately linear positive correlation between total header vibration and total rapeseed header loss.The header frame was analyzed and optimized through modal simulation and testing.The total rapeseed header loss of the improved header was reduced by 33.2% to 46.9%.Abstract. In view of the current large rapeseed header losses of rape combine harvesters, the effects of the header on rapeseed header loss were studied from the perspective of vibration. First, the vibrations at various measuring points on the header during rape harvest were studied using a data acquisition and analysis system while performing collection tests of rapeseed header loss with the sample slot method. The relationships between total header vibration and total rapeseed header loss and between vertical cutter vibration and rapeseed vertical cutter loss were shown to have a positive correlation, and they all increased with the increase in engine speed. Vertical cutter loss accounted for 31.2% to 42.4% of the total rapeseed header loss. Modal analysis and optimization of the header frame were then performed by simulation and test. The natural frequencies of the first-order and second-order modes of the optimized header were increased, and the possibility of resonance with other working parts was eliminated. Finally, the improved header was tested during rape harvest. The results showed that the total vibration of the improved header was reduced by 19.9% to 43.9%, and the total rapeseed header loss was reduced by 33.2% to 46.9%. The vertical cutter vibration was reduced by 30.5% to 49.8%, and the rapeseed vertical cutter loss was reduced by 20.8% to 34.7%. In addition, the vibration and rapeseed loss of the improved header had relatively slow rates of increase with the increase in engine speed. The method of reducing rapeseed loss by reducing the header vibration achieved an obvious and positive effect. Keywords: Frame optimization, Modal analysis, Rape combine harvester, Rapeseed header loss, Vibration.

The Relationship between Consistency of Propulsive Cycles and Maximum Angular Velocity during Wheelchair Racing

2008 ◽  
Vol 24 (3) ◽  
pp. 280-287 ◽  
Author(s):  
Yong “Tai” Wang ◽  
Konstantinos Dino Vrongistinos ◽  
Dali Xu
Keyword(s):  
Angular Velocity ◽  
Upper Limb ◽  
Wheelchair Propulsion ◽  
Upper Arm ◽  
Wheelchair Athletes ◽  
Angular Velocities ◽  
Limb Kinematics ◽  
Analysis System ◽  
The Right ◽  
The Relationship

The purposes of this study were to examine the consistency of wheelchair athletes’ upper-limb kinematics in consecutive propulsive cycles and to investigate the relationship between the maximum angular velocities of the upper arm and forearm and the consistency of the upper-limb kinematical pattern. Eleven elite international wheelchair racers propelled their own chairs on a roller while performing maximum speeds during wheelchair propulsion. A Qualisys motion analysis system was used to film the wheelchair propulsive cycles. Six reflective markers placed on the right shoulder, elbow, wrist joints, metacarpal, wheel axis, and wheel were automatically digitized. The deviations in cycle time, upper-arm and forearm angles, and angular velocities among these propulsive cycles were analyzed. The results demonstrated that in the consecutive cycles of wheelchair propulsion the increased maximum angular velocity may lead to increased variability in the upper-limb angular kinematics. It is speculated that this increased variability may be important for the distribution of load on different upper-extremity muscles to avoid the fatigue during wheelchair racing.

Spinal kinematics in horses with induced back pain

2009 ◽  
Vol 22 (06) ◽  
pp. 448-454 ◽  
Author(s):  
C. B. Gómez Álvarez ◽  
R. Meulenbelt ◽  
C. Johnston ◽  
P. R. van Weeren ◽  
K. Roethlisberger-Holm ◽  
...  
Keyword(s):  
Back Pain ◽  
Gait Analysis ◽  
Poor Performance ◽  
Underlying Mechanism ◽  
Unaffected Side ◽  
Longissimus Dorsi Muscle ◽  
Consistent Change ◽  
Analysis System ◽  
Back Problems ◽  
The Relationship

SummaryBack problems are important contributors to poor performance in sport horses. It has been shown that kinematic analysis can differentiate horses with back problems from asymptomatic horses. The underlying mechanism can, however, only be identified in a uniform, experimental setting.Our aim was to determine if induction of back pain in a well-defined site would result in a consistent change in back movement.Back kinematics were recorded at a walk and trot on a treadmill. Unilateral back pain was then induced by injecting lactic acid into the left longissimus dorsi muscle. Additional measurements were done subsequent to the injections. Data were captured during steady state locomotion at 240 Hz using an infraredbased gait analysis system.After the injections, the caudal thoracic back was more extended at both gaits. The back was also bent more to the left at both gaits. However, at the walk, there was a reversed pattern after a week with bending of the back to the unaffected side.Horses with identical back injuries appear to show similar changes in their back kinematics, as compared to the asymptomatic condition. Unilateral back pain seems to result in an increased extension of the back, as well as compensatory lateral movements.Back movements are complex and subtle, and changes are difficult to detect with the human eye. Present-day gait analysis systems can identify changes in the back movement, and knowledge of the relationship between such changes and the site of injury will be of help in better localising and diagnosing disorders of the equine back.

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