Simultaneous Prediction of Muscle and Contact Forces in the Knee During Gait

2009 ◽  
Author(s):  
Benjamin J. Fregly ◽  
Yi-Chung Lin ◽  
Jonathan P. Walter ◽  
Justin W. Fernandez ◽  
Scott A. Banks ◽  
...  
Keyword(s):  
Contact Forces ◽  
Muscle Coordination ◽  
Reliable Determination ◽  
Joint Forces ◽  
Simultaneous Prediction ◽  
Joint Contact ◽  
Internal Forces ◽  
Independent Ambulation

Walking is important for human health, and independent ambulation predicts quality of life [1]. The study and treatment of neurological and joint disorders that inhibit walking would be more effective if muscle and joint forces could be determined reliably for individual patients. Knowledge of muscle forces is needed to characterize muscle coordination, which is a factor in neurological disorders such as cerebral palsy and stroke, while knowledge of joint contact forces is needed to characterize articular loading, which is a factor in bone and joint disorders such as osteoporosis and osteoarthritis. Reliable determination of these internal forces for individual patients would facilitate the design of customized surgical and rehabilitation treatments that maximize functional outcome.

Simultaneous Prediction of Musculo-Tendon, Joint Contact, Ligament and Bone Forces in the Lower Limb During Gait Using a One-Step Static Optimisation Procedure

2013 ◽  
Author(s):  
Florent Moissenet ◽  
Laurence Cheze ◽  
Raphaël Dumas
Keyword(s):  
Contact Forces ◽  
New Horizons ◽  
Simultaneous Prediction ◽  
Joint Contact ◽  
One Step ◽  
Internal Forces ◽  
Skeletal Model ◽  
Multi Body ◽  
Optimisation Procedure ◽  
Good Agreement

Instrumented prostheses, by measuring joint contact forces during a movement, give nowadays a unique opportunity to validate the ability of musculo-skeletal models in predicting internal forces. In this study, a rigid multi-body musculo-skeletal model, allowing computing the musculo-tendon, joint contact, ligament and bone forces all together by static optimisation, using a weighted criterion, is presented. The results show that the musculo-tendon forces are generally in accordance with the envelopes of the main peaks of the subject’s EMG signals and that the amplitudes and patterns of the predicted joint contact, ligament and bone forces are in a good agreement with the measurements and with the literature. By allowing the introduction of other forces than the musculo-tendon forces in the static optimisation, this study opens new horizons in order to better model the human physiology (e.g., joint pain).

scholarly journals Does the manual insertion torque of smartpegs affect the outcome of implant stability quotients (ISQ) during resonance frequency analysis (RFA)?

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Ingrid Kästel ◽  
Giles de Quincey ◽  
Jörg Neugebauer ◽  
Robert Sader ◽  
Peter Gehrke
Keyword(s):  
Resonance Frequency ◽  
Frequency Analysis ◽  
Insertion Torque ◽  
Resonance Frequency Analysis ◽  
Implant Stability ◽  
Reliable Determination ◽  
Torque Values ◽  
Finger Pressure

Abstract Background There is disagreement about the optimal torque for tightening smartpegs for resonance frequency analysis (RFA). Subjective finger pressure during hand tightening could affect the reliability of the resulting values. The aim of the current study was therefore to assess whether or not the insertion torque of a smartpeg magnetic device influences the implant stability quotient (ISQ) value during RFA. Methods Thirty self-tapping screw implants (XiVE S, Dentsply Sirona Implants, Bensheim, Germany) with a diameter of 3.8 mm and a length of 11 mm were inserted in three cow ribs with a bone quality of D1. The RFA value of each implant was measured (Ostell, FA W&H Dentalwerk, Bürmoos, Austria) in two orthogonal directions (mesial and buccal) after tightening the corresponding smartpeg type 45 with a mechanically defined value of 5 Ncm (Meg Torq device, Megagen, Daegu, South Korea) (test). Additionally, 4 different examiners measured the RFA after hand tightening the smartpegs, and the results were compared (control). Insertion torque values were determined by measuring the unscrew torque of hand seated smartpegs (Tohnichi Manufacturing Co. Ltd, Tokyo, Japan). Results The ISQ values varied from 2 to 11 Ncm by hand tightening and from 2 to 6 Ncm by machine tightening. The comparison of hand and machine tightening of smartpegs displayed only minor differences in the mean ISQ values with low standard deviations (mesial 79.76 ± 2,11, buccal 77.98 ± 2,) and no statistical difference (mesial p = 0,343 and buccal p = 0,890). Conclusions Manual tightening of smartpeg transducers allows for an objective and reliable determination of ISQ values during RFA.

scholarly journals P34 Reliable results in continuous bioanalysis of paediatric renin samples – comprehensive quality assessment within clinical studies in children

2019 ◽  
Vol 104 (6) ◽  
pp. e31.1-e31
Author(s):  
M Feickert ◽  
I Burdman ◽  
N Makowski ◽  
M Ali ◽  
S Farahani ◽  
...  
Keyword(s):  
Heart Failure ◽  
European Medicines Agency ◽  
List Type ◽  
High Quality ◽  
Reliable Determination ◽  
Assay Validation ◽  
Paediatric Study ◽  
Quality Approach

BackgroundAs the initiator of the Renin-Angiotensin-Aldosterone-system, renin plays an essential role in the vicious circle of heart failure. Therefore, renin was determined in the investigators driven ‘Labelling of Enalapril from neonates up to adolescents’ (LENA) study to evaluate its role in paediatric heart failure. Due to the often long-lasting periods of recruitment of paediatric subjects, the assay performance has to be guaranteed over the whole recruiting time. Therefore, to ensure the high quality of the determined renin study samples after successful assay validation,1 a multi-step quality approach was used to get reliable results over a period of 30 months.MethodsBased on a multi-step quality approach consisting of calibration standards (CSs), quality controls (QCs) and incurred sample reanalysis (ISR), study samples of unknown renin concentrations were determined. Results within predefined limits of CSs (6 levels) and QCs according to European Medicine Agency (EMA) guidelines were required for evaluating the study samples.2 ISR was performed for randomly selected paediatric samples to evaluate the long-term accuracy of the validated assay.Results133 analytical runs were conducted for renin from February 2016 to August 2018. In 119 (88.8%) valid runs, a total number of 1414 of CCs and 952 of QCs were determined. Thereof 99.9% of CCs and 98.3% of QCs were in the predefined limits according to EMA. 143 incurred sample pairs were reanalysed resulting in 95.8% of samples within EMA guidelines. Using this multi-step quality approach, the reliable determination of 965 LENA paediatric study samples was guaranteed.ConclusionIn addition to the assay validation, the multi-step quality approach ensured the reliability of the determined renin concentrations in the continuous bioanalysis of the paediatric study samples and guaranteed the high quality of the collected data in the LENA study.ReferencesSchaefer J, Burckhardt BB, Tins J, et al. Validated low-volume immunoassay for the reliable determination of direct renin especially valuable for pediatric investigations. J Immunoass Immunochem 2017;38:579–94. doi:10.1080/15321819.2017.1350707Guideline on bioanalytical method validation. European Medicines Agency, London, UK (2011).Disclosure(s)Martin Feickert, Ilja Burdman, Nina Makowski, Moshin Ali, Anke Bartel, and Bjoern B. Burckhardt declare that there is no conflict of interest. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement n°602295 (LENA)

scholarly journals A White Light Reflectance Spectroscopy Label-Free Biosensor for the Determination of Fungicide Carbendazim

Proceedings ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 45
Author(s):  
Georgios Koukouvinos ◽  
Chrysoula-Evangelia Karachaliou ◽  
Sotirios Kakabakos ◽  
Evangelia Livaniou
Keyword(s):  
White Light ◽  
Reflectance Spectroscopy ◽  
Food Samples ◽  
Environmental Pollutant ◽  
Label Free ◽  
Reliable Determination ◽  
Light Reflectance ◽  
Sensitive Determination

Carbendazim is a broad-spectrum benzimidazole-type fungicide effective against fungi that compromise the safety/quality of food products. Despite its potential usefulness, carbendazim constitutes a major environmental pollutant, being hazardous for humans and animals; therefore, reliable determination of carbendazim levels in water, soil, and food samples remains a highly desirable analytical goal. Herein, an optical (white light reflectance spectroscopy, WLRS) label-free biosensor for fast and sensitive determination of carbendazim is presented. The transducer is a SiO2/Si chip, on which a suitable benzimidazole-conjugate has been immobilized; determination is based on the competitive immunoassay format: A mixture of an in-house developed anti-carbendazim antibody with the calibrators/samples is pumped over the chip, followed by biotinylated secondary antibody and unlabeled streptavidin. The WLRS platform allows for real-time monitoring of biomolecular interactions carried out onto the SiO2/Si chip by transforming the shift in the reflected interference spectrum caused by the immunoreaction to effective biomolecular adlayer thickness. The sensor is capable of detecting carbendazim levels within 28 min (LoD: 20 ng/mL; intra- and inter-assay CVs: ≤6.9% and ≤9.4%, respectively). Excellent analytical characteristics and short analysis time combined with its small size render the proposed WLRS biosensor ideal for future point-of-need determination of carbendazim in food and environmental samples.

Effect of Motion Type on Joint Contact Forces

2019 ◽  
Author(s):  
Anne Schmitz ◽  
Jaclyn Norberg
Keyword(s):  
Force Plate ◽  
Secondary Analysis ◽  
Contact Forces ◽  
Ground Reaction Forces ◽  
Joint Forces ◽  
Joint Contact ◽  
Reaction Forces ◽  
Race Walking ◽  
Impact Exercise ◽  
Dynamics Simulations

Abstract Race walking has grown over the past decade because it provides exercise without the high impact loads of running. In fact, race walking has been shown to result in decreased ground reaction forces. We predict these lower ground reaction forces will extend to knee joint loading as well, thus explaining the decrease rate of knee osteoarthritis in race walkers compared to runners. This is a secondary analysis of instrumented motion capture data collected from fifteen competitive race walkers as they ran and race walked over a force plate. A Visual3D to OpenSim pipeline was used to create muscle actuated forward dynamics simulations of race walking and running. The resulting muscle forces were subsequently used to actuate a discrete element knee model to calculate joint forces. The peak tibiofemoral joint contact load during race walking was 18% lower than the load during running. This load was distributed between the medial and lateral compartments such that the medial load was 27% lower and the lateral load 35% lower in race walking. This suggests race walking is a lower impact exercise safer for the joints. This may be advantageous for people who would like to exercise at a higher intensity that walking provides but have joint problems, e.g. those with osteoarthritis.

Musculoskeletal Loads in Ergometer Rowing

2004 ◽  
Vol 20 (3) ◽  
pp. 317-323 ◽  
Author(s):  
Kazunori Hase ◽  
Motoshi Kaya ◽  
Amy B. Zavatsky ◽  
Suzanne E. Halliday
Keyword(s):  
External Force ◽  
Contact Forces ◽  
Erector Spinae ◽  
Whole Body ◽  
Muscle Forces ◽  
Joint Forces ◽  
Musculoskeletal Problems ◽  
Joint Contact ◽  
Ergometer Rowing ◽  
Skeletal Model

Rowing ergometers can be found in most gyms and fitness centers, but many people who use them regularly have little or no instruction in rowing technique. It is not known whether nonrowers who regularly practice ergometer rowing are at risk of musculoskeletal problems. This study was done to quantify the differences in kinematics, kinetics, and musculoskeletal loading of competitive rowers and nonrowers during ergometer rowing. An experiment was performed to collect kinematic, external force, and EMG data during er-gometer rowing by 5 university-level competitive rowers and 5 nonrowers. Kinematic and external force data were input to a 3-D whole-body musculo-skeletal model which was used to calculate net joint forces and moments, muscle forces, and joint contact forces. The results showed that competitive rowers and nonrowers are capable of rowing an ergometer with generally similar patterns of kinematics and kinetics; however, there are some potentially important differences in how they use their legs and trunk. The competitive rowers generated higher model quadriceps (vastus) muscle forces and pushed harder against the foot cradle, extending their knees more and their trunks less than the nonrowers during the drive phase. They also had higher contact forces at the knee and higher peak lumbar and knee flexion moments. The ratio of average peak vastus force to average peak erector spinae force in the experienced rowers was 1.52, whereas it was only 1.18 in the nonexperienced rowers.

scholarly journals Major Inorganic Ions in Polish Beers

2021 ◽  
Vol 78 (1) ◽  
pp. 48
Author(s):  
Rajmund MICHALSKI ◽  
Edward MUNTEAN ◽  
Aleksandra ŁYKO
Keyword(s):  
Inorganic Ions ◽  
Principal Component ◽  
Inorganic Anions ◽  
Reliable Determination ◽  
Ph Values ◽  
Quality Of Water ◽  
Brewing Process ◽  
Method Optimization

Reliable determination of various components of beers is still a challenge due to their complex matrices. Inorganic ions are very important components of beer; their content depends mainly on the quality of water and additional substances used in the brewing process. The major inorganic anions (F-, Cl-, NO2-, NO3-, PO43-, SO42-) and cations (Na+, K+, Mg2+ and Ca2+) were determined using isocratic ion chromatography with conductivity detection. Method optimization involved six ion-exchange columns; different eluent concentration and flow rates were tested. Optimized methodologies allowed for quick, selective and reliable analysis of these ions in 30 beers available on the Polish market. They were characterized by pH values from 3.19 to 4.64, and conductivity from 1632 to 2662 µS/cm. The content of inorganic anions ranged from 0.2 - 1.1 mg/L for F-; 8 - 235 mg/L for Cl-; NO2- < LOD; 7 - 22 mg/L for NO3-; 44 - 188 mg/L for PO43-, and 10 - 95 mg/L for SO42-. In case of cations, it was 10 - 93 mg/L for Na+; 87 - 329 mg/L for K+; 54 - 329 mg/L for Mg2+, and 10-89 mg/L Ca2+. PCA Principal Component Analysis helped in establishing similarities between the analyzed samples.

A panel of mono- and dinucleotide microsatellite markers is required for reliable determination of the MSI status in colorectal cancer

2001 ◽  
Vol 120 (5) ◽  
pp. A599-A599
Author(s):  
C ARNOLD ◽  
A GOEL ◽  
J CARETHERS ◽  
L WASSERMAN ◽  
C COMPTON ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Microsatellite Markers ◽  
Reliable Determination

Tingkat Pemahaman Kompetensi Guru Pada Mahasiswa Pendidikan Geografi Sebagai Calon Guru Geografi

2020 ◽  
Vol 21 (1) ◽  
pp. 102-117
Author(s):  
Novia Zalmita ◽  
Muhajirah Muhajirah ◽  
Abdul Wahab Abdi
Keyword(s):  
Prospective Teachers ◽  
Prospective Teacher ◽  
Quantitative Description ◽  
Population Data ◽  
Geography Education ◽  
Teacher Competence ◽  
Education Department ◽  
Long Time

One that influences human resource indicators is education. The teacher is a profession as a job of academic specialization in a relatively long time in college. Understanding related to teacher competence is very important to have by a prospective teacher because it can affect the quality of performance as a professional teacher. The teacher's competence is known as pedagogic, professional, social and personality competencies. The issue in this study is how the competency of the teacher of the Department of Geography Education FKIP Unsyiah as a prospective teacher of geography? The purpose of this study was to determine the competence of teachers in the Department of Geography Education FKIP Unsyiah as prospective geography teachers. Quantitative description approach is used in this study to find answers to the issue. The population in this study were students of the Department of Geography Education FKIP Unsyiah class of 2015 and 2016 who had been declared to have passed the Micro Teaching and Magang Kependidikan 3 course totaling 50 people. Because the population is small and can be reached, the determination of the sample using total sampling techniques so that the sample in this study is the whole population. Data collection is done by distributing test questions to respondents. The data was analyzed using the descriptive statistics percentage formula. The results of the study indicate that the level of teacher competence of Geography Education Department students as prospective teachers is in the moderate category, namely as many as 22 respondents (44%). A total of 12 respondents (24%) were in the high category, 15 respondents (30%) were in the low category and 1 respondent (2%) were in the very low category.

Sign in / Sign up

Export Citation Format

Share Document