scholarly journals Ageing-Related Gait Adaptations to Knee Joint Kinetics: Implications for the Development of Knee Osteoarthritis

2020 ◽  
Vol 10 (24) ◽  
pp. 8881
Author(s):  
Hanatsu Nagano ◽  
Rezaul Begg
Keyword(s):  
Knee Joint ◽  
Knee Osteoarthritis ◽  
Repeated Measures ◽  
Mixed Model ◽  
Step Length ◽  
Knee Adduction Moment ◽  
Future Research ◽  
Vertical Force ◽  
Step Width ◽  
Joint Kinetics

The prevalence of knee osteoarthritis (OA) increases with ageing and this research aimed to identify gait adaptations that could reduce OA by investigating ageing effects on knee joint biomechanics. Participants were 24 healthy young males (18–35 yrs) and 14 healthy older males (60–75 yrs). Three-dimensional motion capture (Optotrak) and walkway-embedded force plates (AMTI) recorded their natural preferred-speed walking and the following parameters were computed: knee adduction moment, knee joint vertical force, foot contact angle, toe-out angle, foot centre of pressure displacement, time to foot flat, step length, step width and double support time. A 2 × 2 (age × limb) repeated measures mixed model analysis of variance design determined main effects and interactions. Pearson’s correlations between knee kinetic parameters and stride phase variables were also calculated. Both knee adduction moment and vertical joint force were larger in the older group. Relative to the young controls, older individuals showed a longer time to foot flat, less toe-out angle and wider steps. Correlation analysis suggested that reduced toe-out angle and increased step width were associated with lower knee adduction moment; furthermore, knee joint vertical force reduced with greater step length. Future research could focus on intervention strategies for managing excessive knee joint stresses to prevent the ageing-related development of knee OA.

Power of Modified Brown-Forsythe and Mixed-Model Approaches in Split-Plot Designs

Methodology ◽  
2017 ◽  
Vol 13 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Pablo Livacic-Rojas ◽  
Guillermo Vallejo ◽  
Paula Fernández ◽  
Ellián Tuero-Herrero
Keyword(s):  
Repeated Measures ◽  
Statistical Power ◽  
Mixed Model ◽  
Covariance Structure ◽  
Simulation Method ◽  
Future Research ◽  
Repeated Measures Design ◽  
Fixed And Random Effects ◽  
Split Plot ◽  
High Level

Abstract. Low precision of the inferences of data analyzed with univariate or multivariate models of the Analysis of Variance (ANOVA) in repeated-measures design is associated to the absence of normality distribution of data, nonspherical covariance structures and free variation of the variance and covariance, the lack of knowledge of the error structure underlying the data, and the wrong choice of covariance structure from different selectors. In this study, levels of statistical power presented the Modified Brown Forsythe (MBF) and two procedures with the Mixed-Model Approaches (the Akaike’s Criterion, the Correctly Identified Model [CIM]) are compared. The data were analyzed using Monte Carlo simulation method with the statistical package SAS 9.2, a split-plot design, and considering six manipulated variables. The results show that the procedures exhibit high statistical power levels for within and interactional effects, and moderate and low levels for the between-groups effects under the different conditions analyzed. For the latter, only the Modified Brown Forsythe shows high level of power mainly for groups with 30 cases and Unstructured (UN) and Autoregressive Heterogeneity (ARH) matrices. For this reason, we recommend using this procedure since it exhibits higher levels of power for all effects and does not require a matrix type that underlies the structure of the data. Future research needs to be done in order to compare the power with corrected selectors using single-level and multilevel designs for fixed and random effects.

Modifying Stride Length in Isolation and in Combination With Foot Progression Angle and Step Width Can Improve Knee Kinetics Related to Osteoarthritis; A Preliminary Study in Healthy Subjects

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Shannon N. Edd ◽  
Sami Bennour ◽  
Baptiste Ulrich ◽  
Brigitte M. Jolles ◽  
Julien Favre
Keyword(s):  
Repeated Measures ◽  
Healthy Subjects ◽  
Stride Length ◽  
Knee Adduction Moment ◽  
Step Width ◽  
Foot Placement ◽  
Knee Kinetics ◽  
Foot Progression Angle ◽  
Knee Loading ◽  
Preliminary Study

Abstract The purpose of this study was to determine the effects of modifying stride length (SL) on knee adduction and flexion moments, two markers of knee loading associated with medial-compartment knee osteoarthritis (OA) progression. This study also tested if SL modifications, in addition to foot progression angle (FP) and step width (SW) modifications, provide solutions in more subjects for reducing knee adduction moment (KAM) without increasing knee flexion moment (KFM), potentially protecting the joint. Fourteen healthy subjects (six female) were enrolled in this preliminary study. Walking trials were collected first without instructions, and then following foot placement instructions for 50 combinations of SL, FP, and SW modifications. Repeated measures analysis of variance was used to detect group-average effects of footprint modifications on maximum KAM and KFM and on KAM impulse. Subject-specific dose–responses between footprint modifications and kinetics changes were modeled with linear regressions, and the models were used to identify modification solutions, per subject, for various kinetics change conditions. Shorter SL significantly decreased the three kinetics measures (p < 0.01). Potential solutions for 10% reductions in maximum KAM and KAM impulse without increasing maximum KFM were identified for five subjects with FP and SW modifications. A significantly higher proportion of subjects had solutions when adding SL modifications (11 subjects, p = 0.04). In conclusion, SL is a valuable parameter to modify, especially in combination with FP and SW modifications, to reduce markers of medial knee loading. Future work is needed to extend these findings to osteoarthritic knees.

scholarly journals Investigating Care Dependency and Its Relation to Outcome (ICARE): Results From a Naturalistic Study of an Intensive Day Treatment Program for Depression

2021 ◽  
Vol 12 ◽  
Author(s):  
Sarah Glanert ◽  
Svenja Sürig ◽  
Ulrike Grave ◽  
Eva Fassbinder ◽  
Sebastian Schwab ◽  
...  
Keyword(s):  
Treatment Outcome ◽  
Depressive Symptoms ◽  
Repeated Measures ◽  
Mixed Model ◽  
Depressive Symptomatology ◽  
Future Research ◽  
Clinical Trial Registration ◽  
Levels Of Care ◽  
Repeated Measures Design ◽  
Care Dependency

Background: This study explores the association of experienced dependency in psychotherapy as measured with the CDQ (Care Dependency Questionnaire) and treatment outcome in depression. Furthermore, the course of care dependency and differences in the CDQ scores depending on the received type of treatment, MCT (metacognitive therapy), or CBASP (cognitive behavioral analysis system of psychotherapy), were investigated.Methods: The study follows a prospective, parallel group observational design. Patients suffering from depression received an 8-week intensive day clinic program, which was either CBASP or MCT. The treatment decision was made by clinicians based on the presented symptomatology and with regard to the patients' preferences. The patients reported depressive symptoms with the QIDS-SR16 (Quick Inventory of Depressive Symptomatology) and levels of experienced care dependency with the German version of the CDQ on a weekly basis. Mixed-model analyses were run to account for the repeated-measures design.Results: One hundred patients were included in the analyses. Results indicate that higher levels of care dependency might predict a less favorable outcome of depressive symptomatology. Levels of care dependency as well as depressive symptoms decreased significantly over the course of treatment. There was no significant between-group difference in care dependency between the two treatment groups.Conclusion: The results suggest that care dependency might be associated with a worse treatment outcome in depressed patients. In general, care dependency seems to be a dynamic construct, as it is changing over time, while the levels of care dependency seem to be independent from the received type of treatment. Future research should continue investigating the mechanisms of care dependency in a randomized controlled design.Clinical Trial Registration:https://www.drks.de/drks_web/, identifier: DRKS00023779.

scholarly journals The 2- and 8-week effects of decompressive brace use in people with medial compartment knee osteoarthritis

2015 ◽  
Vol 40 (4) ◽  
pp. 447-453 ◽  
Author(s):  
Eric M Lamberg ◽  
Robert Streb ◽  
Marc Werner ◽  
Ian Kremenic ◽  
James Penna
Keyword(s):  
Knee Osteoarthritis ◽  
Repeated Measures ◽  
Knee Adduction Moment ◽  
Knee Brace ◽  
Knee Motion ◽  
Noninvasive Treatment ◽  
Medial Knee ◽  
Medial Knee Osteoarthritis ◽  
Peak Knee ◽  
Second Peak

Background: Knee osteoarthritis is a prevalent disease. Unloading the affected compartment using a brace is a treatment option. Objectives: To determine whether a decompressive knee brace alters loading in medial knee osteoarthritis following 2 and 8 weeks of use. Study design: Within subjects; pre- and post-testing. Methods: A total of 15 individuals with medial knee osteoarthritis attended four sessions: baseline, fitting, 2 weeks after fitting (post), and 8 weeks after fitting (final). A gait analysis was performed at baseline (without knee brace), post and final. Knee adduction impulse, first and second peak knee adduction moment, knee motion, and walking velocity were calculated. Participants also recorded hours and steps taken while wearing the brace. Results: On average, the brace was worn for more than 6 h/day. Through use of repeated-measures analysis of variance, it was determined that the knee adduction impulse and second peak knee adduction moment were reduced ( p < 0.05) at post and final compared to baseline (36% and 34% reduction in knee adduction impulse, 26% reduction in second peak knee adduction moment for post and final, respectively). Furthermore, participants walked faster with increased knee motion during stance. Conclusion: The studied decompressive brace was effective in reducing potentially detrimental forces at the knee—knee adduction impulse and second peak knee adduction moment during the stance phase of gait. Clinical relevance The data from this study suggest that use of a medial unloading brace can reduce potentially detrimental adduction moments at the knee. Clinicians should use this evidence to advocate for use of this noninvasive treatment for people presenting with medial knee osteoarthritis.

7. Frontal Plane Knee Loading during Bodyweight Squat Performance: Effects of Stance Width and Foot Rotation

2016 ◽  
Author(s):  
David Kingston
Keyword(s):  
Body Weight ◽  
Knee Joint ◽  
Repeated Measures ◽  
Inverse Dynamics ◽  
Exercise Prescription ◽  
Reaction Force ◽  
Frontal Plane ◽  
The Body ◽  
Knee Adduction Moment ◽  
Squat Exercise

The bodyweight squat is routinely used for conditioning of the knee musculature. In the performance of this exercise, modifications in the initial standing position may result in altered frontal plane kneel loading, and hence may potentially be used for targeted exercise prescription. The purpose of this study is to quantify the frontal plane mechanical loading on the knee joint whilst performing the bodyweight squat exercise, and to examine the effects of varying stance width and foot rotation angle. Twenty-four participants (14 males) performed 4 randomized sets of 8 repetitions of the body weight resistant squat exercise in the following conditions: 1) Shoulder width (SW) stance with parallel feet; 2) SW stance with feet externally rotated 30°; 3) 140% SW stance with parallel feet, and; 4) 140% SW stance with the feet externally rotated by 30°. The adduction/abduction knee joint moment experienced across conditions was calculated using inverse dynamics procedures. Moment waveforms were subjected to Principal Component (PC) analysis, with 3 PC’s retained based on a 90% trace criteria. Following, a 1-way repeated measures ANOVA and pair wise comparisons were used to discern differences between conditions. Omnibus test results indicate significant differences across conditions for PC1 and PC2 (p<0.01), Post hoc comparisons and waveform interpretation of PC1 extreme scores showed that the magnitude of the adduction moment was higher throughout the movement in the foot rotated conditions vs. the parallel feet conditions in both stance widths (mean Z scores .69 & .65 vs. -.88 & -.45, p<0.01, respectively). For PC2, significant differences were found between the 2 parallel feet conditions and the 2 foot rotated conditions, as well as between the foot conditions in the wide stance squats. PC2 differences were interpreted as phase shift operators. We found that modification of foot rotation slightly alters the magnitude and timing of knee adduction moment component during performance of the body weight squat. The observed magnitude differences are presumably a consequence of alteration in the location of the point of application of the ground reaction force during the initial standing posture. The findings may assist clinicians in exercise prescription decision making.

scholarly journals 92 Digestawell® fiber improves in-vitro digestibility of alfalfa and coastal bermudagrass hay fed to horses

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 29-30
Author(s):  
Brittany S Perron ◽  
Ashley Wagner-Wells ◽  
Jamie Boyd ◽  
Ivan Girard ◽  
Noheli Guiterrez ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Mixed Model ◽  
Future Research ◽  
In Vitro Digestibility ◽  
Dry Matter Digestibility ◽  
Forage Digestibility ◽  
Coastal Bermudagrass ◽  
Microbial Efficiency

Abstract Enhanced microbial activity in the equine hindgut increases nutrient availability, reduces fecal waste, and adds value to low quality forages. The dietary supplement DigestaWell® Fiber (DF; fibrolytic cofactors: methionine and B vitamins), designed to increase microbial efficiency, has been shown to improve in-vitro digestibility of alfalfa and tall fescue forages after 48h incubation. The objective of this study was to determine if DF would improve in-vitro dry matter digestibility (DMD) and ADF digestibility (ADFD) of alfalfa and coastal bermudagrass hays incubated for 48h or 72h. Utilizing a crossover design, four mature Quarter Horse mares were fed 2% BW daily of alfalfa (AF; 32.8% NDF, 27.1% ADF) or coastal bermudagrass (CB; 63.2% NDF, 35.4% ADF) hay for 19d periods. DMD and ADFD were determined after 48h or 72h incubation with or without treatment (320mg/L DF) at 37.5°C in an ANKOM Daisy II incubator inoculated with 200g fresh feces. Forage samples were run in triplicate. Data were transformed to approximate normality, then analyzed using a repeated measures mixed model in SAS with main effects of forage, treatment, incubation time, and feeding period, and statistically significant interactions. Across incubation times, DMD was higher for AF than CB (P < 0.01; 49.4% vs 42.1%). Across forages, DMD was higher at 72h than at 48h incubation (P < 0.01; 47.5% vs 43.9%). DF improved DMD across forages at 48h (P = 0.03), but not at 72h (P = 0.47). Across incubation times, DF improved DMD of CB (P < 0.01), but not AF (P = 0.79). Additionally, across both forages and both incubation times, DF improved ADFD (P < 0.01). In conclusion, DF may improve microbial fermentation in the equine hindgut. Future research should investigate in-vivo effects of oral supplementation of DF on forage digestibility measures.

scholarly journals OPTIC FLOW IMPROVES SPATIAL GAIT FUNCTIONING ESPECIALLY IN MEDIOLATERAL DIRECTION

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S658-S658
Author(s):  
Farahnaz Fallahtafti ◽  
Hyeon Jung Kim ◽  
Jennifer M Yentes ◽  
Dawn Venema ◽  
Julie Blaskewicz Boron
Keyword(s):  
Older Adults ◽  
Optic Flow ◽  
Repeated Measures ◽  
Visual Information ◽  
Step Length ◽  
Step Width ◽  
Gait Performance ◽  
Double Support ◽  
Double Support Time ◽  
Support Time

Abstract Instances where multiple tasks are completed simultaneously are considered high cognitive load situations (HCLS, also called dual-task), potentially affecting gait performance in older adults. Walking while talking is a common HCLS that requires additional cognitive resources. Optic flow (OF) provides visual information about speed and direction of self-motion, and thus, may ameliorate gait deficits under HCLS. This study aimed to identify the effect of HCLS, as well as OF, on gait performance in older adults. The HCLS included walking while talking on the phone, compared to walking alone. Fifteen older adults (70.86±4.7yrs) underwent four experimental conditions: walking alone with(1) and without OF(2), as well as walking while talking with(3) and without OF(4). Step width, step length, and double support time were measured and examined with 2(HCLS) x 2(OF) repeated-measures ANOVAs. There was a main effect of OF; step width was narrower with OF compared to without OF (p=0.048). For step length, there was a significant interaction between HCLS and OF (p=0.045). Without OF, there were no differences in step length; however, with OF step length was significantly longer when walking alone compared to when walking while talking (p=0.002). Double support time was not affected by HCLS or OF. Considering younger adults have longer and narrower steps compared to older adults, OF may have enhanced step width regardless of HCLS and step length when walking only. Using OF in training programs designed for older adults, could be a potential factor to improve spatial gait function, more so in the mediolateral direction.

scholarly journals 16 Digestawell® fiber improves in-vitro digestibility of alfalfa and coastal bermudagrass hay fed to horses

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 10-10
Author(s):  
Brittany S Perron ◽  
Ashley Wagner-Wells ◽  
Jamie Boyd ◽  
Ivan Girard ◽  
Noheli Guiterrez ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Mixed Model ◽  
Future Research ◽  
In Vitro Digestibility ◽  
Dry Matter Digestibility ◽  
Forage Digestibility ◽  
Coastal Bermudagrass ◽  
Microbial Efficiency

Abstract Enhanced microbial activity in the equine hindgut increases nutrient availability, reduces fecal waste, and adds value to low quality forages. The dietary supplement DigestaWell® Fiber (DF; fibrolytic cofactors: methionine and B vitamins), designed to increase microbial efficiency, has been shown to improve in-vitro digestibility of alfalfa and tall fescue forages after 48-h incubation. The objective of this study was to determine if DF would improve in-vitro dry matter digestibility (DMD) and ADF digestibility (ADFD) of alfalfa and coastal bermudagrass hays incubated for 48h or 72h. Utilizing a crossover design, four mature Quarter Horse mares were fed 2% BW daily of alfalfa (AF; 32.8% NDF, 27.1% ADF) or coastal bermudagrass (CB; 63.2% NDF, 35.4% ADF) hay for 19-d periods. DMD and ADFD were determined after 48-h or 72-h incubation with or without treatment (320mg/L DF) at 37.5°C in an ANKOM Daisy II incubator inoculated with 200g fresh feces. Forage samples were run in triplicate. Data were transformed to approximate normality, then analyzed using a repeated measures mixed model in SAS with main effects of forage, treatment, incubation time, and feeding period, and statistically significant interactions. Across incubation times, DMD was higher for AF than CB (P < 0.01; 49.4% vs 42.1%). Across forages, DMD was higher at 72h than at 48h incubation (P < 0.01; 47.5% vs 43.9%). DF improved DMD across forages at 48h (P = 0.03), but not at 72h (P = 0.47). Across incubation times, DF improved DMD of CB (P < 0.01), but not AF (P = 0.79). Additionally, across both forages and both incubation times, DF improved ADFD (P < 0.01). In conclusion, DF may improve microbial fermentation in the equine hindgut. Future research should investigate in-vivo effects of oral supplementation of DF on forage digestibility measures.

Sign in / Sign up

Export Citation Format

Share Document