scholarly journals Prolonged Load Carriage Impacts Magnitude and Velocity of Knee Adduction Biomechanics

Biomechanics ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 346-357
Author(s):  
Gaervyn J. Salverda ◽  
Micah D. Drew ◽  
Samantha M. Krammer ◽  
Tyler N. Brown
Keyword(s):  
Potential Risk ◽  
Mixed Model ◽  
Maximum Velocity ◽  
Load Carriage ◽  
Knee Adduction Moment ◽  
Knee Oa ◽  
Time To Peak ◽  
Mixed Model Anova ◽  
Three Body

Background: This study determined whether prolonged load carriage increased the magnitude and velocity of knee adduction biomechanics and whether increases were related to knee varus thrust or alignment. Methods: Seventeen participants (eight varus thrust and nine control) had knee adduction quantified during 60-min of walking (1.3 m/s) with three body-borne loads (0 kg, 15 kg, and 30 kg). Magnitude, average and maximum velocity, and time to peak of knee adduction biomechanics were submitted to a mixed model ANOVA. Results: With the 0 and 15 kg loads, varus thrust participants exhibited greater magnitude (p ≤ 0.037, 1.9–2.3°), and average (p ≤ 0.027, up to 60%) and maximum velocity (p ≤ 0.030, up to 44%) of varus thrust than control, but differences were not observed with the 30 kg load. The 15 and 30 kg loads led to significant increases in magnitude (p ≤ 0.017, 15–25%) and maximum velocity (p ≤ 0.017, 11–20%) of knee adduction moment, while participants increased magnitude (p ≤ 0.043, up to 0.3°) and maximum velocity (p ≤ 0.022, up to 5.9°/s and 6.7°/s) for knee adduction angle and varus thrust at minutes 30 and 60. Static alignment did not differ between groups (p = 0.412). Conclusion: During prolonged load carriage, all participants increased the magnitude and velocity of knee adduction biomechanics and the potential risk of knee OA.

scholarly journals Prolonged Load Carriage Impacts Magnitude and Velocity of Knee Adduction Biomechanics

2021 ◽  
Author(s):  
Gaervyn John Salverda
Keyword(s):  
Repeated Measures ◽  
Maximum Velocity ◽  
Frontal Plane ◽  
Load Carriage ◽  
Service Members ◽  
Occupational Activity ◽  
Knee Oa ◽  
Time To Peak ◽  
Projection Angle ◽  
Three Body

Introduction: Adopting knee adduction biomechanics during prolonged load carriage, a common military occupational activity, may increase service members knee osteoarthritis (OA) risk. Although service members reportedly increase knee adduction motions and moments during prolonged load carriage, it is unknown if either body borne load or walk duration increases velocity of knee adduction biomechanics, and subsequent knee OA risk. Varus thrust and alignment are also related to greater knee OA risk, yet it is unknown whether varus thrust and/or alignment are related to magnitude and velocity of knee adduction biomechanics during prolonged load carriage. Purpose: To determine whether body borne load and walk duration impacted magnitude and velocity of knee adduction biomechanics, or whether increases in knee adduction biomechanics are related to knee varus thrust or alignment. Methods: Seventeen participants (11 male/6 female, 23.2 ± 2.9 yrs, 1.8 ± .09 m, 71.0 ± 12.1 kg) had knee adduction biomechanics quantified while walking 1.3 m/s for 60 minutes with three body borne loads (0 kg, 15 kg, and 30 kg). Specifically, peak, average and maximum velocity, as well as time to peak, for knee adduction angle and moment, and varus thrust (first 16% of stance) were calculated at minutes 0, 30, and 60 of the load carriage task. Static knee alignment was calculated as the frontal plane knee projection angle. Statistical Analysis: Participants were defined as varus thrust (VT, n=8) or control (CON, n=9). Then, each knee adduction measurement was submitted to a repeated measures ANCOVA to test the main effect and interaction between body borne load (0 kg, 15 kg, and 30 kg), time (minutes 0, 30, and 60), and group (VT and CON), with static alignment considered a covariate. Results: A significant 3-way interaction for maximum varus thrust velocity (p=0.014), revealed the VT group exhibited greater maximum velocity at minutes 0 through 60 (p ≤ 0.038) with the 0 kg load, and minutes 0 and 60 (p ≤ 0.043) with the 15 kg load. Significant load by group interactions for magnitude (p=0.008) and average velocity (p=0.013) of varus thrust, and maximum KAA velocity (p=0.041) revealed VT participants exhibited larger and faster varus thrust and knee adduction angle than the CON group with the 0 kg and 15 kg loads (p < 0.050). Additionally, both magnitude and maximum velocity of KAM increased with the addition of load (p=0.009 and p=0.004), and walk duration increased magnitude of varus thrust (p=0.044). Static alignment was not a significant covariate for any knee adduction measure (p > 0.05). Conclusion: During prolonged load carriage participants adopted larger, faster knee adduction biomechanics, potentially increasing risk of knee OA. The VT group exhibited greater knee OA risk, and larger, faster knee adduction motions when walking with the lighter (0 kg and 15 kg) loads; while CON adopted increases in knee adduction biomechanics related to knee OA with the heavy (30 kg) load.

scholarly journals Effects of Prolonged Load Carriage of Knee Adduction Biomechanics

2020 ◽  
Author(s):  
Micah Daniel Drew
Keyword(s):  
Statistical Analysis ◽  
Repeated Measures ◽  
Joint Angle ◽  
Load Carriage ◽  
Knee Adduction Moment ◽  
Initial Contact ◽  
Data Sets ◽  
Knee Oa ◽  
Peak Knee ◽  
Three Body

Introduction: Incidence of knee osteoarthritis (OA) in service members is twice that of the general population. Yet, it is currently unknown how body borne load and duration of walking with body borne load impact knee adduction, biomechanics linked to progression and severity of OA. Purpose: This study sought to examine magnitude and variability of knee adduction joint angle and moment throughout a prolonged walking task with body borne load. Methods: Eighteen participants had knee biomechanics quantified every five minutes while they walked at 1.3 m/s during a 60-minute over-ground walking task with three body-borne loads (unloaded, 15 kg and 30 kg). Statistical Analysis: Thirteen participants with complete data sets were submitted to statistical analysis. Peak of stance (0-100%) knee adduction joint angle and moment, initial contact and range of adduction motion, and coefficient of variation of peak knee adduction angle and moment, and range of adduction motion were submitted to a repeated measures ANOVA to test the main effect and interaction between time (0, 15, 30, 45 and 60 min) and load (0 ,15 and 30 kg). Results: Body borne load significantly increased peak knee adduction moment (p 0.05); whereas duration of walking task significantly increased peak stance (p 0.05). Conclusion: Prolonged walking with body borne load increased knee adduction biomechanics related to knee OA pathogenesis. The larger knee adduction moment exhibited with the addition of load and the larger knee adduction angle exhibited towards the end of the prolonged walking task may increase loading of the medial knee joint compartment and increase risk of knee OA.

scholarly journals 109 Phytate supplementation has minimal impact on mineral digestibility in horses

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 89-90
Author(s):  
Katy Brinkley-Bissinger ◽  
Laura M Cersosimo ◽  
Kathleen E Sullivan ◽  
Shannon E Livingston ◽  
Jill M Bobel ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Mixed Model ◽  
Divalent Cations ◽  
Basal Diet ◽  
Minimal Impact ◽  
Inductively Coupled ◽  
Mixed Model Anova ◽  
Microbial Phytase ◽  
And Performance ◽  
Inorganic Mineral

Abstract Phosphorus in equine rations is supplied by inorganic mineral fortification or naturally-occurring P in forages and grains. Up to 70% of P in plant material is bound to phytate. In monogastrics like poultry and swine, phytate can reduce absorption of P and divalent cations, but the extent that this occurs in horses is unknown. This study tested the hypothesis that phytate decreases mineral digestibility in horses. Six mature Quarter Horse geldings (mean ± SE, 586 ± 19 kg, 10 ± 1.5 y) were randomly assigned to two treatments applied in a cross-over design: IP6 (Ca-Mg-phytate isolated from rice bran fed at 15 mg phytic acid/kg BW) or CON (equivalent Ca, Mg and P from inorganic minerals to match intake from IP6). The level of phytate added represented an amount present in grain-rich rations typically fed to broodmares, growing horses and performance athletes. Supplements were added to a basal diet (1.75% BW, DM basis) consisting of 75% timothy hay and 25% roughage-based concentrate. Each 14-d period had an 11-d treatment adaptation followed by a 3-d total fecal collection. After acid digestion, P was determined colorimetrically and other minerals were determined by inductively coupled plasma spectrometry. Data were analyzed using mixed model ANOVA. Intakes of Ca, P, Mg, Zn, Cu and Fe were similar between treatments (140, 72, 40, 1.05, 0.24, and 1.78 mg/kg BW respectively). Apparent P digestibility (18.8 and 17%, SEM 1.9; P = 0.41) and estimates of true P digestibility (32.8 and 30.8%, SEM 1.9; P = 0.39) were similar between CON and IP6. Apparent digestibilities of other minerals were also not affected by IP6 supplementation. Findings suggest horses have sufficient microbial phytase activity in the gastrointestinal tract to mitigate impacts of dietary phytate. Higher levels or different forms of phytate and marginal mineral intake may yield different results.

scholarly journals Multidisciplinary Evaluation of Pacifier Removal on Oro-Dentofacial Structures: A Controlled Clinical Trial

2021 ◽  
Vol 9 ◽  
Author(s):  
Kelly Guedes de Oliveira Scudine ◽  
Camila Nobre de Freitas ◽  
Kizzy Silva Germano Nascimento de Moraes ◽  
Silvana Bommarito ◽  
Rosana de Fátima Possobon ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Mixed Model ◽  
Control Group ◽  
Controlled Clinical Trial ◽  
Functional Changes ◽  
Mixed Model Anova ◽  
And Function ◽  
Clinical Trials Registry ◽  
Facial Anthropometry ◽  
Over Time

It is well recognized that pacifier habit leads to occlusal and orofacial functional changes in children. However, the effects of the interruption of prolonged pacifier habit on the development of the dento-facial complex has not yet been fully characterized. Thus, the aim of this study was to investigate the influence of pacifier removal on aspects of oro-dentofacial morphology and function in preschool children. For that, a pacifier group (n = 28) and a control group (n = 32) of 4-year-old children with and without pacifier habit, respectively, were followed up by a group of dentists and speech therapists at baseline, 6 and 12 months after habit removal. Bite force and lip pressure were assessed using digital systems, and the evaluation of breathing and speech functions was performed using validated protocols, together with the measurements of dental casts and facial anthropometry. The Two-way mixed model ANOVA was used in data analysis. After 12 months, a decrease in malocclusion frequency was observed in pacifier group. Additionally, a change over time was observed in facial, intermolar and palate depth measurements, as well in bite and lip forces and speech function scores, increasing in both groups (p &lt; 0.01). The upper and lower intercanine widths and breathing scores differed between groups at baseline and changed over time reducing the differences. The presence of speech distortions was more frequent in the pacifier group at baseline and decreased over time (p &lt; 0.05). The interruption of pacifier habit improved the maxillary and mandibular intercanine widths, as well as the breathing and speech functions, overcoming the oro-dentofacial changes found.Trial Registration: This clinical trial was registered in the Brazilian Clinical Trials Registry (ReBEC; http://www.ensaiosclinicos.gov.br/), protocol no. RBR-728MJ2.

Quantifying Achievable Levels of Improvement in Knee Joint Biomechanics During Gait After Total Knee Arthroplasty Relative to Osteoarthritis Severity

2020 ◽  
pp. 1-9
Author(s):  
Jereme B. Outerleys ◽  
Michael J. Dunbar ◽  
Glen Richardson ◽  
Cheryl L. Hubley-Kozey ◽  
Janie L. Astephen Wilson
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Joint ◽  
Knee Arthroplasty ◽  
Frontal Plane ◽  
Knee Adduction Moment ◽  
Patient Specific ◽  
Knee Biomechanics ◽  
Knee Oa ◽  
Joint Biomechanics ◽  
Total Knee

Total knee arthroplasty (TKA) surgery improves knee joint kinematics and kinetics during gait for most patients, but a lack of evidence exists for the level and incidence of improvement that is achieved. The objective of this study was to quantify patient-specific improvements in knee biomechanics relative to osteoarthritis (OA) severity levels. Seventy-two patients underwent 3-dimensional (3D) gait analysis before and 1 year after TKA surgery, as well as 72 asymptomatic adults and 72 with moderate knee OA. A combination of principal component analysis and discriminant analyses were used to categorize knee joint biomechanics for patients before and after surgery relative to asymptomatic, moderate, and severe OA. Post-TKA, 63% were categorized with knee biomechanics consistent with moderate OA, 29% with severe OA, and 8% asymptomatic. The magnitude and pattern of the knee adduction moment and angle (frontal plane features) were the most significant contributors in discriminating between pre-TKA and post-TKA knee biomechanics. Standard of care TKA improves knee biomechanics during gait to levels most consistent with moderate knee OA and predominately targets frontal plane features. These results provide evidence for the level of improvement in knee biomechanics that can be expected following surgery and highlight the biomechanics most targeted by surgery.

scholarly journals The Synergistic Effect of Leukocyte Platelet-Rich Fibrin and Micrometer/Nanometer Surface Texturing on Bone Healing around Immediately Placed Implants: An Experimental Study in Dogs

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Rodrigo F. Neiva ◽  
Luiz Fernando Gil ◽  
Nick Tovar ◽  
Malvin N. Janal ◽  
Heloisa Fonseca Marao ◽  
...  
Keyword(s):  
Bone Healing ◽  
Mixed Model ◽  
Surface Texturing ◽  
Contralateral Side ◽  
Nanometer Scale ◽  
Textured Surface ◽  
Beagle Dogs ◽  
Implant Surface ◽  
Mixed Model Anova ◽  
Micrometer Scale

Aims. This study evaluated the effects of L-PRF presence and implant surface texture on bone healing around immediately placed implants.Methods. The first mandibular molars of 8 beagle dogs were bilaterally extracted, and implants (Blossom™, Intra-Lock International, Boca Raton, FL) were placed in the mesial or distal extraction sockets in an interpolated fashion per animal. Two implant surfaces were distributed per sockets: (1) dual acid-etched (DAE, micrometer scale textured) and (2) micrometer/nanometer scale textured (Ossean™ surface). L-PRF (Intraspin system, Intra-Lock International) was placed in a split-mouth design to fill the macrogap between implant and socket walls on one side of the mandible. The contralateral side received implants without L-PRF. A mixed-model ANOVA (atα=0.05) evaluated the effect of implant surface, presence of L-PRF, and socket position (mesial or distal), individually or in combination on bone area fraction occupancy (BAFO).Results. BAFO values were significantly higher for the Ossean relative to the DAE surface on the larger mesial socket. The presence of L-PRF resulted in higher BAFO. The Ossean surface and L-PRF presence resulted in significantly higher BAFO.Conclusion.L-PRF and the micro-/nanometer scale textured surface resulted in increased bone formation around immediately placed implants.

scholarly journals Orange/Red Fluorescence of Active Caries by Retrospective Quantitative Light-Induced Fluorescence Image Analysis

2016 ◽  
Vol 50 (3) ◽  
pp. 295-302 ◽  
Author(s):  
Grace Felix Gomez ◽  
George J. Eckert ◽  
Andrea Ferreira Zandona
Keyword(s):  
Image Analysis ◽  
Mixed Model ◽  
Assessment System ◽  
Caries Detection ◽  
Percentage Increase ◽  
Caries Activity ◽  
Red Fluorescence ◽  
Mixed Model Anova ◽  
Retrospective Clinical Study ◽  
Final Observation

This retrospective clinical study determined the association of caries activity and orange/red fluorescence on quantitative light-induced fluorescence (QLF) images of surfaces that progressed to cavitation, as determined by clinical visual examination. A random sample of QLF images from 565 children (5-13 years) previously enrolled in a longitudinal study was selected. Buccal, lingual and occlusal surface images obtained after professional brushing at baseline and every 4 months over a 4-year period were analyzed for red fluorescence. Surfaces that progressed (n = 224) to cavitation according to the International Caries Detection and Assessment System (ICDAS 0/1/2/3/4 to 5/6 or filling), and surfaces that did not progress (n = 486) were included. QA2 image analysis software outputs the percentage increase of the red/green components as ΔR and area of ΔR (areaΔR) at different thresholds. Mixed-model ANOVA was used to compare progressive and nonprogressive surfaces to account for correlations of red fluorescence (ΔR and areaΔR) between surfaces within a subject. The first analysis used the first observation for each surface or the first available visit if the surface was unerupted (baseline), while the second analysis used the last observation prior to cavitation for surfaces that progressed and the last observation for surfaces that did not progress (final). There was a significant (p < 0.05) association between red fluorescence and progression to cavitation at thresholds ΔR0, ΔR10, ΔR20, ΔR60, ΔR70, ΔR80, ΔR90 and ΔRmax at baseline and for ΔR0 and ΔR10 at the final observation. Quantification of orange/red fluorescence may help to identify lesions that progress to cavitation. Future studies identifying microbiological factors causing orange/ red fluorescence and its caries activity are indicated.

Comparative evaluation of the specificity and sensitivity of isometric indices of contractility

1975 ◽  
Vol 228 (2) ◽  
pp. 506-510 ◽  
Author(s):  
WW Parmley ◽  
L Chuck ◽  
L Yeatman
Keyword(s):  
Muscle Length ◽  
Maximum Velocity ◽  
Mechanical Index ◽  
Contractile State ◽  
Time To Peak ◽  
Specificity And Sensitivity ◽  
Relative Dependence ◽  
State Changes ◽  
Definition Of

It is generally held that a useful mechanical index of contractility is one that is unchanged by changes in initial muscle length, but that changes in appropriate direction and magnitude with a change in contractile state. A number of isometric indices were measured in vitro in isolated cat papillary muscles to quantitate their relative dependence on initial muscle length and contractile state. Results indicate that no one isometric index completely fulfills the definition of an ideal index of contractile state. In particular, indices that change considerably with alterations in contractile state (e.g., maximum dF/dt) are also moderately dependent on preload. Conversely, indices that are moderately insensitive to changes in contractile state (e.g., time-to-peak force) are also insensitive to changes in contractile state. Changes in extrapolated maximum velocity and peak VCE were similar and were less sensitive to changes in contractile state than maximum dF/dt. The most sensitive in vitro index of contractility appears to be maximum dF/dt at a constant preload.

Sign in / Sign up

Export Citation Format

Share Document