scholarly journals Kinematics of the Normal Knee during Dynamic Activities: A Synthesis of Data from Intracortical Pins and Biplane Imaging

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Xavier Gasparutto ◽  
Florent Moissenet ◽  
Yoann Lafon ◽  
Laurence Chèze ◽  
Raphaël Dumas
Keyword(s):  
Gold Standard ◽  
Degrees Of Freedom ◽  
Weight Bearing ◽  
Model Development ◽  
Measurement Methods ◽  
Standard Measurement ◽  
Normal Knee ◽  
Dynamic Weight ◽  
Tibiofemoral Kinematics

Few studies have provided in vivo tibiofemoral kinematics of the normal knee during dynamic weight-bearing activities. Indeed, gold standard measurement methods (i.e., intracortical pins and biplane imaging) raise ethical and experimental issues. Moreover, the conventions used for the processing of the kinematics show large inconsistencies. This study aims at synthesising the tibiofemoral kinematics measured with gold standard measurement methods. Published kinematic data were transformed in the standard recommended by the International Society of Biomechanics (ISB), and a clustering method was applied to investigate whether the couplings between the degrees of freedom (DoFs) are consistent among the different activities and measurement methods. The synthesised couplings between the DoFs during knee flexion (from 4° of extension to −61° of flexion) included abduction (up to −10°); internal rotation (up to 15°); and medial (up to 10 mm), anterior (up to 25 mm), and proximal (up to 28 mm) displacements. These synthesised couplings appeared mainly partitioned into two clusters that featured all the dynamic weight-bearing activities and all the measurement methods. Thus, the effect of the dynamic activities on the couplings between the tibiofemoral DoFs appeared to be limited. The synthesised data might be used as a reference of normal in vivo knee kinematics for prosthetic and orthotic design and for knee biomechanical model development and validation.

In Vivo Motion Characteristics of the Lower Cervical Spine During Dynamic Weight-Bearing Flexion-Extension

2015 ◽  
Vol 15 (10) ◽  
pp. S183-S184
Author(s):  
Sean J. Driscoll ◽  
Haiqing Mao ◽  
Shaobai Wang ◽  
Weiye Zhong ◽  
Guoan Li ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Weight Bearing ◽  
Lower Cervical Spine ◽  
Dynamic Weight ◽  
Flexion Extension ◽  
Motion Characteristics

scholarly journals In vivo contact kinematics and contact forces of the knee after total knee arthroplasty during dynamic weight-bearing activities

2008 ◽  
Vol 41 (10) ◽  
pp. 2159-2168 ◽  
Author(s):  
Kartik M. Varadarajan ◽  
Angela L. Moynihan ◽  
Darryl D’Lima ◽  
Clifford W. Colwell ◽  
Guoan Li
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Weight Bearing ◽  
Contact Forces ◽  
Dynamic Weight ◽  
Contact Kinematics ◽  
Total Knee

scholarly journals Differences in tibiofemoral kinematics between the unloaded robotic passive path and a weightbearing knee simulator

2012 ◽  
Vol 3 (2) ◽  
pp. 2 ◽  
Author(s):  
Markus Wünschel ◽  
Ulf Leichtle ◽  
JiaHsuan Lo ◽  
Nikolaus Wülker ◽  
Otto Müller
Keyword(s):  
Knee Joint ◽  
Degrees Of Freedom ◽  
Weight Bearing ◽  
Reaction Force ◽  
Joint Kinematics ◽  
Vertical Ground Reaction Force ◽  
Knee Simulator ◽  
6 Degrees Of Freedom ◽  
Tibiofemoral Kinematics

Cadaveric <em>in vitro</em> studies are essential to test hypotheses concerning surgical manipulations in the same individual. Robotic technologies as well as different knee-models have been developed to get an in-depth comprehension of knee joint kinematics. The purpose of this study was to compare utilization of these different established principles. Ten human cadaveric knee specimens were used to measure the kinematics during a weight-bearing flexion in a 6-degrees-of-freedom knee simulator. While flexing the knee, joint quadriceps muscle forces were dynamically simulated to reach a vertical ground reaction force of 100N. Fourteen knee specimens were mounted in 6-degrees-of-freedom robotic manipulator with a universal force sensor. The unloaded flexing motion of each specimen was measured by finding positions for each degree of flexion where all forces are minimal (passive path). The kinematic data of the kneesimulator and the robot concerning <em>internal-external</em> rotation, <em>anterior-posterior</em> translation, <em>varus-valgus</em> motion, and <em>medial-lateral </em>translation was examined. For all investigated degrees of freedom the kinematics of the robotic passive path differed from the loaded kinematics in the knee simulator. Simulated bodyweight as well as the examination method used has a substantial influence on joint kinematics during flexion which has to be considered when interpreting biomechanical studies as well as clinical tests.

scholarly journals Mechanistic physiology-based pharmacokinetic modeling to elucidate vincristine-induced peripheral neuropathy following treatment with novel kinase inhibitors

2021 ◽  
Author(s):  
Venkatesh Pilla Reddy ◽  
Adrian J. Fretland ◽  
Diansong Zhou ◽  
Shringi Sharma ◽  
Buyun Chen ◽  
...  
Keyword(s):  
Peripheral Neuropathy ◽  
Kinase Inhibitors ◽  
Pbpk Model ◽  
Model Development ◽  
Limited Information ◽  
Time Curve ◽  
Btk Inhibitor ◽  
Chop Therapy

Abstract Purpose Limited information is available regarding the drug–drug interaction (DDI) potential of molecular targeted agents and rituximab plus cyclophosphamide, doxorubicin (hydroxydaunorubicin), vincristine (Oncovin), and prednisone (R-CHOP) therapy. The addition of the Bruton tyrosine kinase (BTK) inhibitor ibrutinib to R-CHOP therapy results in increased toxicity versus R-CHOP alone, including higher incidence of peripheral neuropathy. Vincristine is a substrate of P-glycoprotein (P-gp, ABCB1); drugs that inhibit P-gp could potentially cause increased toxicity when co-administered with vincristine through DDI. While the combination of the BTK inhibitor acalabrutinib and R-CHOP is being explored clinically, the DDI potential between these therapies is unknown. Methods A human mechanistic physiology-based pharmacokinetic (PBPK) model of vincristine following intravenous dosing was developed to predict potential DDI interactions with combination therapy. In vitro absorption, distribution, metabolism, and excretion and in vivo clinical PK parameters informed PBPK model development, which was verified by comparing simulated vincristine concentrations with observed clinical data. Results While simulations suggested no DDI between vincristine and ibrutinib or acalabrutinib in plasma, simulated vincristine exposure in muscle tissue was increased in the presence of ibrutinib but not acalabrutinib. Extrapolation of the vincristine mechanistic PBPK model to other P-gp substrates further suggested DDI risk when ibrutinib (area under the concentration–time curve [AUC] ratio: 1.8), but not acalabrutinib (AUC ratio: 0.92), was given orally with venetoclax or digoxin. Conclusion Overall, these data suggest low DDI risk between acalabrutinib and P-gp substrates with negligible increase in the potential risk of vincristine-induced peripheral neuropathy when acalabrutinib is added to R-CHOP therapy.

4D in in vivo 2-photon laser scanning fluorescence microscopy with sample motion in 6 degrees of freedom

2011 ◽  
Vol 200 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Sabine Scheibe ◽  
Mario M. Dorostkar ◽  
Christian Seebacher ◽  
Rainer Uhl ◽  
Frank Lison ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Laser Scanning ◽  
Degrees Of Freedom ◽  
Sample Motion ◽  
6 Degrees Of Freedom

Accuracy of Orthodontic Force and Tooth Movement Measurements

1996 ◽  
Vol 23 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Dan Lundgren ◽  
Py Owman-Moll ◽  
Jüri Kurol ◽  
Birgit Mårtensson
Keyword(s):  
Tooth Movement ◽  
Mean Value ◽  
Measurement Methods ◽  
Calibration Data ◽  
Force Measurements ◽  
Accuracy Of Measurement ◽  
Measuring Machine ◽  
Initial Force ◽  
Level Of Agreement

This study was designed to test the accuracy of measurement methods for assessment of force and tooth movement in orthodontic procedures. Daily in vivo measurements of the force produced by activated archwires showed that the initial force declined substantially (by 20 per cent of mean value) within 3 days. Both the ‘trueness’ (validity) and precision of the force measurements, obtained with a strain gauge, were found to be high (SD values were 1·0 cN and 0·4 cN, respectively). Horizontal tooth movements were measured with three different instruments: a slide calliper, a co-ordinate measuring machine, and laser measuring equipment based on holograms. There was a good level of agreement between these methods. This was also confirmed by calibration data. The precision of the methods was (SD values) 0·06, 0·07, and 0·13 mm, respectively. The benefits of the use of the co-ordinate measuring machine are obvious, since it can measure tooth movements in relation to reference planes in all directions.

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