Publications by authors named "Sonia Duprey"

18 Publications

  • Page 1 of 1

Glenohumeral joint and muscles functions during a lifting task.

J Biomech 2021 Sep 19;126:110641. Epub 2021 Jul 19.

School of Kinesiology and Exercise Science, Faculty of Medicine, University of Montreal, QC, Canada; Sainte-Justine Hospital Research Centre, Montreal, QC, Canada.

The mobility of the healthy shoulder depends on complex interactions between the muscles spanning its glenohumeral joint. These interactions ensure the stability of this joint. While previous studies emphasized the complexity of the glenohumeral stability, it is still not clear how the kinematics and muscles interact and adapt to ensure a healthy function of the glenohumeral joint. To understand the function of each muscle and degree of freedom of the glenohumeral joint in executing an above-the shoulder box handling task while ensuring stability, we adapted an index-based approach previously used to characterize the functions of the lower limb joints and muscles during locomotion. Forty participants lifted two loads (6 Vs. 12 kg) from hip to eye level. We computed the mechanical powers of the glenohumeral joint and its spanning muscles. We characterized the function of muscles and degrees of freedom using function indices. The function of the glenohumeral joint underlined its compliancy and design for a large range of motion, while the rotator cuff indices emphasized their stabilizing function. The overall muscle functions underlined the complexity of the glenohumeral stability that goes beyond the rotator cuff. Additionally, the load increase was compensated with changes in the functions that seem to favor joint stability. The implemented approach represents a synthetized tool that could quantify the glenohumeral joint and muscles behavior during tridimensional upper limb tasks, which might offer additional insight into motor control strategies and functional alterations related to pathologies or external parameters (e.g., load).
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http://dx.doi.org/10.1016/j.jbiomech.2021.110641DOI Listing
September 2021

Pelvis and femur shape prediction using principal component analysis for body model on seat comfort assessment. Impact on the prediction of the used palpable anatomical landmarks as predictors.

PLoS One 2019 27;14(8):e0221201. Epub 2019 Aug 27.

Univ Lyon, Université Claude Bernard Lyon 1, Lyon, France.

A personalized pelvis and femur shape is required to build a finite element buttock thigh model when experimentally investigating seating discomfort. The present study estimates the shape of pelvis and femur using a principal component analysis (PCA) based method with a limited number of palpable anatomical landmarks (ALs) as predictors. A leave-one-out experiment was designed using 38 pelvises and femurs from a same sample of adult specimens. As expected, prediction errors decrease with the number of ALs. Using the maximum number of easily palpable ALs (13 for pelvis and 4 for femur), average errors were 5.4 and 4.8 mm respectively for pelvis and femur. Better prediction was obtained when the shapes of pelvis and femur were predicted separately without merging the data of both bones. Results also show that the PCA based method is a good alternative to predict hip and lumbosacral joint centers with an average error of 5.0 and 9.2 mm respectively.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0221201PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6711593PMC
March 2020

Finite element models of the thigh-buttock complex for assessing static sitting discomfort and pressure sore risk: a literature review.

Comput Methods Biomech Biomed Engin 2018 Mar;21(4):379-388

a Univ Lyon , Université de Lyon, Université Claude Bernard Lyon 1, IFSTTAR , Lyon , France.

Being seated for long periods, while part of many leisure or occupational activities, can lead to discomfort, pain and sometimes health issues. The impact of prolonged sitting on the body has been widely studied in the literature, with a large number of human-body finite element models developed to simulate sitting and assess seat-induced discomfort or to investigate the biomechanical factors involved. Here, we review the finite element models developed to investigate sitting discomfort or risk of pressure sores. Our study examines finite element models from twenty-seven papers, seventeen dedicated to assessing seating discomfort and ten dedicated to investigating pressure ulcers caused by prolonged sitting. The models' mesh composition and material properties are found to differ widely. These models share a lack of validation and generally make little allowance for anthropometric diversity.
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http://dx.doi.org/10.1080/10255842.2018.1466117DOI Listing
March 2018

MRI-based experimentations of fingertip flat compression: Geometrical measurements and finite element inverse simulations to investigate material property parameters.

J Biomech 2018 01 29;67:166-171. Epub 2017 Nov 29.

Univ Lyon, Université Claude Bernard Lyon 1, IFSTTAR, LBMC UMR_T9406, F69622 Lyon, France. Electronic address:

Modeling human-object interactions is a necessary step in the ergonomic assessment of products. Fingertip finite element models can help investigating these interactions, if they are built based on realistic geometrical data and material properties. The aim of this study was to investigate the fingertip geometry and its mechanical response under compression, and to identify the parameters of a hyperelastic material property associated to the fingertip soft tissues. Fingertip compression tests in an MRI device were performed on 5 subjects at either 2 or 4 N and at 15° or 50°. The MRI images allowed to document both the internal and external fingertip dimensions and to build 5 subject-specific finite element models. Simulations reproducing the fingertip compression tests were run to obtain the material property parameters of the soft tissues. Results indicated that two ellipses in the sagittal and longitudinal plane could describe the external fingertip geometry. The internal geometries indicated an averaged maximal thickness of soft tissues of 6.4 ± 0.8 mm and a 4 ± 1 mm height for the phalanx bone. The averaged deflections under loading went from 1.8 ± 0.3 mm at 2 N, 50° to 3.1 ± 0.2 mm at 4 N, 15°. Finally, the following set of parameters for a second order hyperelastic law to model the fingertip soft tissues was proposed: C=0.59 ± 0.09 kPa and C = 2.65 ± 0.88 kPa. These data should facilitate further efforts on fingertip finite element modeling.
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http://dx.doi.org/10.1016/j.jbiomech.2017.11.024DOI Listing
January 2018

Effect of various upper limb multibody models on soft tissue artefact correction: A case study.

J Biomech 2017 09 31;62:102-109. Epub 2017 Jan 31.

Univ Lyon, Université Claude Bernard Lyon 1, IFSTTAR, LBMC UMR_T9406, F69622 Lyon, France.

Soft tissue artefacts (STA) introduce errors in joint kinematics when using cutaneous markers, especially on the scapula. Both segmental optimisation and multibody kinematics optimisation (MKO) algorithms have been developed to improve kinematics estimates. MKO based on a chain model with joint constraints avoids apparent joint dislocation but is sensitive to the biofidelity of chosen joint constraints. Since no recommendation exists for the scapula, our objective was to determine the best models to accurately estimate its kinematics. One participant was equipped with skin markers and with an intracortical pin screwed in the scapula. Segmental optimisation and MKO for 24-chain models (including four variations of the scapulothoracic joint) were compared against the pin-derived kinematics using root mean square error (RMSE) on Cardan angles. Segmental optimisation led to an accurate scapula kinematics (1.1°≤RMSE≤3.3°) even for high arm elevation angles. When MKO was applied, no clinically significant difference was found between the different scapulothoracic models (0.9°≤RMSE≤4.1°) except when a free scapulothoracic joint was modelled (1.9°≤RMSE≤9.6°). To conclude, using MKO as a STA correction method was not more accurate than segmental optimisation for estimating scapula kinematics.
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http://dx.doi.org/10.1016/j.jbiomech.2017.01.031DOI Listing
September 2017

Kinematic models of the upper limb joints for multibody kinematics optimisation: An overview.

J Biomech 2017 09 9;62:87-94. Epub 2016 Dec 9.

Univ Lyon, Université Claude Bernard Lyon 1, IFSTTAR, LBMC UMR_T9406, F69622, Lyon France.

Soft tissue artefact (STA), i.e. the motion of the skin, fat and muscles gliding on the underlying bone, may lead to a marker position error reaching up to 8.7cm for the particular case of the scapula. Multibody kinematics optimisation (MKO) is one of the most efficient approaches used to reduce STA. It consists in minimising the distance between the positions of experimental markers on a subject skin and the simulated positions of the same markers embedded on a kinematic model. However, the efficiency of MKO directly relies on the chosen kinematic model. This paper proposes an overview of the different upper limb models available in the literature and a discussion about their applicability to MKO. The advantages of each joint model with respect to its biofidelity to functional anatomy are detailed both for the shoulder and the forearm areas. Models capabilities of personalisation and of adaptation to pathological cases are also discussed. Concerning model efficiency in terms of STA reduction in MKO algorithms, a lack of quantitative assessment in the literature is noted. In priority, future studies should concern the evaluation and quantification of STA reduction depending on upper limb joint constraints.
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http://dx.doi.org/10.1016/j.jbiomech.2016.12.005DOI Listing
September 2017

Upper Limb Kinematics Using Inertial and Magnetic Sensors: Comparison of Sensor-to-Segment Calibrations.

Sensors (Basel) 2015 Jul 31;15(8):18813-33. Epub 2015 Jul 31.

Institut National de Recherche et de Sécurité (INRS), 54519 Vandoeuvre-lès-Nancy, France.

Magneto-Inertial Measurement Unit sensors (MIMU) display high potential for the quantitative evaluation of upper limb kinematics, as they allow monitoring ambulatory measurements. The sensor-to-segment calibration step, consisting of establishing the relation between MIMU sensors and human segments, plays an important role in the global accuracy of joint angles. The aim of this study was to compare sensor-to-segment calibrations for the MIMU-based estimation of wrist, elbow, and shoulder joint angles, by examining trueness ("close to the reference") and precision (reproducibility) validity criteria. Ten subjects performed five sessions with three different operators. Three classes of calibrations were studied: segment axes equal to technical MIMU axes (TECH), segment axes generated during a static pose (STATIC), and those generated during functional movements (FUNCT). The calibrations were compared during the maximal uniaxial movements of each joint, plus an extra multi-joint movement. Generally, joint angles presented good trueness and very good precision in the range 5°-10°. Only small discrepancy between calibrations was highlighted, with the exception of a few cases. The very good overall accuracy (trueness and precision) of MIMU-based joint angle data seems to be more dependent on the level of rigor of the experimental procedure (operator training) than on the choice of calibration itself.
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http://dx.doi.org/10.3390/s150818813DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4570347PMC
July 2015

Three-Dimensional Rotations of the Scapula During Arm Abduction: Evaluation of the Acromion Marker Cluster Method in Comparison With a Model-Based Approach Using Biplanar Radiograph Images.

J Appl Biomech 2015 Oct 18;31(5):396-402. Epub 2015 Jun 18.

Laboratoire de Biomécanique et de Mécanique des Chocs, Université de Lyon, Lyon, France.

Noninvasive methods enabling measurement of shoulder bone positions are paramount in clinical and ergonomics applications. In this study, the acromion marker cluster (AMC) method is assessed in comparison with a model-based approach allowing scapula tracking from low-dose biplanar radiograph images. Six healthy male subjects participated in this study. Data acquisition was performed for 6 arm abduction positions (0°, 45°, 90°, 120°, 150°, 180°). Scapula rotations were calculated using the coordinate systems and angle sequence was defined by the ISB. The comparison analysis was based on root mean square error (RMSE) calculation and nonparametric statistical tests. RMSE remained under 8° for 0° to 90° arm abduction and under 13.5° for 0° to 180° abduction; no significant differences were found between the 2 methods. Compared with previous works, an improved accuracy of the AMC approach at high arm abduction positions was obtained. This could be explained by the different sources of data used as the "gold standard."
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http://dx.doi.org/10.1123/jab.2014-0244DOI Listing
October 2015

The tolerance of the human body to automobile collision impact - a systematic review of injury biomechanics research, 1990-2009.

Accid Anal Prev 2015 Jul 2;80:7-17. Epub 2015 Apr 2.

Director General for Traffic, Ministry of Interior, Spain. Electronic address:

Road traffic injuries account for 1.3 million deaths per year world-wide. Mitigating both fatalities and injuries requires a detailed understanding of the tolerance of the human body to external load. To identify research priorities, it is necessary to periodically compare trends in injury tolerance research to the characteristics of injuries occurring in the field. This study sought to perform a systematic review on the last twenty years of experimental injury tolerance research, and to evaluate those results relative to available epidemiologic data. Four hundred and eight experimental injury tolerance studies from 1990-2009 were identified from a reference index of over 68,000 papers. Examined variables included the body regions, ages, and genders studied; and the experimental models used. Most (20%) of the publications studied injury to the spine. There has also been a substantial volume of biomechanical research focused on upper and lower extremity injury, thoracic injury, and injury to the elderly - although these injury types still occur with regularity in the field. In contrast, information on pediatric injury and physiological injury (especially in the central nervous system) remains lacking. Given their frequency of injury in the field, future efforts should also include improving our understanding of tolerances and protection of vulnerable road users (e.g., motorcyclists, pedestrians).
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http://dx.doi.org/10.1016/j.aap.2015.03.004DOI Listing
July 2015

Global sensitivity analysis of the joint kinematics during gait to the parameters of a lower limb multi-body model.

Med Biol Eng Comput 2015 Jul 18;53(7):655-67. Epub 2015 Mar 18.

Université de Lyon, 69622, Lyon, France.

Sensitivity analysis is a typical part of biomechanical models evaluation. For lower limb multi-body models, sensitivity analyses have been mainly performed on musculoskeletal parameters, more rarely on the parameters of the joint models. This study deals with a global sensitivity analysis achieved on a lower limb multi-body model that introduces anatomical constraints at the ankle, tibiofemoral, and patellofemoral joints. The aim of the study was to take into account the uncertainty of parameters (e.g. 2.5 cm on the positions of the skin markers embedded in the segments, 5° on the orientation of hinge axis, 2.5 mm on the origin and insertion of ligaments) using statistical distributions and propagate it through a multi-body optimisation method used for the computation of joint kinematics from skin markers during gait. This will allow us to identify the most influential parameters on the minimum of the objective function of the multi-body optimisation (i.e. the sum of the squared distances between measured and model-determined skin marker positions) and on the joint angles and displacements. To quantify this influence, a Fourier-based algorithm of global sensitivity analysis coupled with a Latin hypercube sampling is used. This sensitivity analysis shows that some parameters of the motor constraints, that is to say the distances between measured and model-determined skin marker positions, and the kinematic constraints are highly influencing the joint kinematics obtained from the lower limb multi-body model, for example, positions of the skin markers embedded in the shank and pelvis, parameters of the patellofemoral hinge axis, and parameters of the ankle and tibiofemoral ligaments. The resulting standard deviations on the joint angles and displacements reach 36° and 12 mm. Therefore, personalisation, customisation or identification of these most sensitive parameters of the lower limb multi-body models may be considered as essential.
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http://dx.doi.org/10.1007/s11517-015-1269-8DOI Listing
July 2015

An experimental investigation on push force and its perception during a flexible hose insertion task encountered in a truck assembly line.

Ergonomics 2014 19;57(9):1416-26. Epub 2014 Jun 19.

a Université de Lyon , F-69622 Lyon , France.

Unlabelled: The push force and its perception when inserting a flexible hose laterally into a connector were investigated. Effects of hose diameter, glove, target position and obstacle condition were studied. Maximum voluntary insertion forces (MVFs) under similar working conditions were also measured. The larger the diameter, the higher the force required. The peak axial forces for the hoses of 6, 12 and 16 mm in diameter were on average respectively 94, 122 and 184 N, representing 45%, 61% and 93% of MVF. Glove condition, target position and obstacle did not significantly affect the axial insertion force and moment, but they did affect effort perception. Lower effort was perceived with gloves and high and near position. High intra- and inter-individual variability in insertion force for a given hose may suggest that feedback of successful insertion was insufficient. The recognition of a successful insertion must be ensured to avoid unnecessary extra force exertion.

Practitioner Summary: The effects of glove, hose diameter, target location and obstacle on push force and its perception were studied when inserting a flexible hose. Solutions for improving the recognition of a successful insertion and the hose/connector system design must be found to reduce force exertion to safe levels.
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http://dx.doi.org/10.1080/00140139.2014.924575DOI Listing
May 2016

Response of the human torso to lateral and oblique constant-velocity impacts.

Ann Adv Automot Med 2010 ;54:27-40

University of Virginia, Center for Applied Biomechanics, Charlottesville, VA, USA.

The objective of this study was to provide new biomechanical response data for the thorax with lateral and oblique loading, so as to support the development of safety systems for side impact protection that would offer the level of protection that has been achieved in frontal impact. Three male human cadavers were successively impacted by an impactor system delivering a constant velocity impact from the left and the right sides at three levels (shoulder, upper chest and mid-chest). Different impact directions were also chosen for each side: lateral, +15° posterolateral, -15° anterolateral. One subject was impacted at 1, 3 and 6 m/s whereas the other two subjects were impacted at 3 m/s only. A total of nineteen tests was performed. The impact force and the chest lateral deflection were measured using respectively a standard data acquisition system and also an optoelectronic stereophotogrammetric system (OSS). After each test, attempts were made to detect rib fractures by palpation, and a necropsy of the torso was performed after the tests series to document the injuries produced by all the tests. Overall, the peak impact force increased from the lowest impact level (mid-chest) to the highest (shoulder) and was found to be rate-sensitive. The force-deflection relationship was non linear for the shoulder impacts (stiffness increased with increasing deflection) whereas stiffness was nearly constant for the mid- and upper-chest impacts. The anterolateral impacts to the mid- and upper-chest generated more rib fractures than the other impact directions.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3242539PMC
April 2016

Influence of joint constraints on lower limb kinematics estimation from skin markers using global optimization.

J Biomech 2010 Oct 10;43(14):2858-62. Epub 2010 Aug 10.

Université de Lyon, F-69622 Lyon, France.

In order to obtain the lower limb kinematics from skin-based markers, the soft tissue artefact (STA) has to be compensated. Global optimization (GO) methods rely on a predefined kinematic model and attempt to limit STA by minimizing the differences between model predicted and skin-based marker positions. Thus, the reliability of GO methods depends directly on the chosen model, whose influence is not well known yet. This study develops a GO method that allows to easily implement different sets of joint constraints in order to assess their influence on the lower limb kinematics during gait. The segment definition was based on generalized coordinates giving only linear or quadratic joint constraints. Seven sets of joint constraints were assessed, corresponding to different kinematic models at the ankle, knee and hip: SSS, USS, PSS, SHS, SPS, UHS and PPS (where S, U and H stand for spherical, universal and hinge joints and P for parallel mechanism). GO was applied to gait data from five healthy males. Results showed that the lower limb kinematics, except hip kinematics, knee and ankle flexion-extension, significantly depend on the chosen ankle and knee constraints. The knee parallel mechanism generated some typical knee rotation patterns previously observed in lower limb kinematic studies. Furthermore, only the parallel mechanisms produced joint displacements. Thus, GO using parallel mechanism seems promising. It also offers some perspectives of subject-specific joint constraints.
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http://dx.doi.org/10.1016/j.jbiomech.2010.06.010DOI Listing
October 2010

A parametric study of hard tissue injury prediction using finite elements: consideration of geometric complexity, subfailure material properties, CT-thresholding, and element characteristics.

Traffic Inj Prev 2010 Jun;11(3):286-93

European Center for Injury Prevention (ECIP), Universidad de Navarra, Navarra, Facultad de Medicina. Departamento de Medicina preventiva y Salud Pública, Edificio Investigacíon, Pamplona, Spain.

Objective: The objectives of this study were to examine the axial response of the clavicle under quasistatic compressions replicating the body boundary conditions and to quantify the sensitivity of finite element-predicted fracture in the clavicle to several parameters.

Methods: Clavicles were harvested from 14 donors (age range 14-56 years). Quasistatic axial compression tests were performed using a custom rig designed to replicate in situ boundary conditions. Prior to testing, high-resolution computed tomography (CT) scans were taken of each clavicle. From those images, finite element models were constructed. Factors varied parametrically included the density used to threshold cortical bone in the CT scans, the presence of trabecular bone, the mesh density, Young's modulus, the maximum stress, and the element type (shell vs. solid, triangular vs. quadrilateral surface elements).

Results: The experiments revealed significant variability in the peak force (2.41 +/- 0.72 kN) and displacement to peak force (4.9 +/- 1.1 mm), with age (p < .05) and with some geometrical traits of the specimens. In the finite element models, the failure force and location were moderately dependent upon the Young's modulus. The fracture force was highly sensitive to the yield stress (80-110 MPa).

Conclusion: Neither fracture location nor force was strongly dependent on mesh density as long as the element size was less than 5 x 5 mm(2). Both the fracture location and force were strongly dependent upon the threshold density used to define the thickness of the cortical shell.
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http://dx.doi.org/10.1080/15389581003709902DOI Listing
June 2010

Biomechanical properties of the costovertebral joint.

Med Eng Phys 2010 Mar 24;32(2):222-7. Epub 2009 Dec 24.

University of Virginia, Center for Applied Biomechanics, Charlottesville, VA, USA.

Proper modeling of the human trunk requires a quantitative assessment of the stiffness of the costovertebral joints. Twelve samples (adjacent thoracic vertebrae and one rib segment) were harvested from three subjects. The ribs were loaded in the cranial-caudal direction, the ventral-dorsal direction and in torsion around the cervical rib axis. The force applied to and the displacement of the loading point on the rib were measured and used to determine the moment-angle responses. Characteristic average curves and boundary curves containing the dataset were developed. The torsion response presented a range of motion--defined as the change in the angle for an applied moment varying from -0.1 to 0.1 Nm--of 16.9+/-6.8 degrees which is more than three times the range in cranial-caudal flexion and five times the range in ventral-dorsal flexion. Statistical tests showed a significant difference between these ranges of motion. Significant inter-subject variability was observed for the cranial-caudal flexion (p<0.05) while no intra-subject variability appeared. The characteristic moment-angle responses of the joints were well represented by third order polynomials (R(2)>0.9). This study expands and supplements the limited data available in the literature. Furthermore, it provides biomechanical data (closed-form moment-angle functions) that can be directly integrated into spine-ribcage models.
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http://dx.doi.org/10.1016/j.medengphy.2009.12.001DOI Listing
March 2010

Clavicle fracture prediction: simulation of shoulder lateral impacts with geometrically personalized finite elements models.

J Trauma 2010 Jan;68(1):177-82

From the Université de Lyon, Lyon, France.

Background: Human body numerical models can help to develop protection devices against effects of road crashes. In the context of a side impact, a shoulder model able to predict shoulder injuries and more especially clavicle fracture would be helpful.

Methods: A shoulder model derived from an existing finite element model of the human body representing an average male (50th percentile), HUMOS1, has been upgraded. An isolated clavicle model was assessed thanks to experimental corridors derived from dynamic tests up to failure. Then, the whole upgraded shoulder model was evaluated by comparison with results from experimental side impact tests on the shoulder. Eventually, the upgraded model was geometrically personalized toward the anthropometry of the subjects and its ability to simulate fractures was assessed.

Results: The isolated clavicle model was assessed as validated. The upgraded 50th percentile shoulder model provided accurate results in the subinjurious domain. At higher velocities, the personalized models produced realistic shoulder injuries: clavicle fracture was accurately predicted in four cases of six, the model was conservative for the two other cases.

Conclusion: The upgraded shoulder model presented here was successfully submitted to a rigorous assessment process. Once geometrically personalized, it provided positive results for clavicle fracture prediction. As clavicle fracture is the major shoulder injury, this model could help the design of safety devices for shoulder protection. Furthermore, this study enhances the need for geometrical personalization methods when using finite element model for injury risk prediction.
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http://dx.doi.org/10.1097/TA.0b013e318190bf5bDOI Listing
January 2010

Experimental and computational investigation of human clavicle response in anterior-posterior bending loading - biomed 2009.

Biomed Sci Instrum 2009 ;45:6-11

University of Virginia, Charlottesville, VA.

Clavicle fractures are common injuries in three-point belt restrained occupants involved in frontal and lateral car collisions. Therefore, better understanding of clavicle loading which occurs during an impact and clavicle structural/material properties could help in the optimization of seatbelt restraint systems. Six clavicles from three post mortem human subjects were tested in a three point -bending test setup with pinned-pinned boundary conditions. The clavicle extremities were fixed into potting cups which were able to rotate freely about a single rotational axis (inferior-superior axis) and then, were loaded in the anterior-posterior direction by an impactor at the middle shaft level. Two tests were performed on each clavicle: a) A noninjurious quasi-static test (1mm/s impactor rate) up to approximately 400 N b) A dynamic test (1m/s impactor rate) to failure. Reaction forces and moments were measured at both clavicle supports. The results showed an averaged clavicle stiffness of 211+/-30 N/mm in the quasi-static tests. Concerning the dynamic tests to failure, the average maximum force was 1159+/-133 N, the average maximum deflection was 4.9+/-0.7 mm, the average clavicle stiffness was 237+/-64 N/mm, and the average maximum strain was 1+/-0.2%. The most common failure location was the middle third of the bone, which is consistent with literature data. A finite element model of a human clavicle was developed and used to simulate the tests. The optimization of the elastic parameters of clavicle finite element model during the simulations of quasi-static tests provided an 8.1 GPa Young modulus for cortical bone. In addition to providing validation data for computational human models and dummies, the results of this study may lend insight into the development of advanced belt restraint systems.
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February 2016

Influence of geometrical personalization on the simulation of clavicle fractures.

J Biomech 2008 13;41(1):200-7. Epub 2007 Aug 13.

LBMC-Biomechanics and Impact Mechanics Laboratory (UMR-T 9406 INRETS/UCBL), Case 24, 25 av. F Mitterrand, 69675 Bron, France.

Finite element body models enable the evaluation of car occupant protection. In general, these models represent average males and inter-individual geometry variability is not taken into account. As the most frequent shoulder injury during car lateral accidents is a clavicle fracture, the purpose of this study is to investigate whether clavicle geometry has an influence on bone response until failure, and whether geometrical personalization of clavicle models is required. Eighteen clavicles from 9 subjects (5 males and 4 females, mean age: 76 +/- 12 years) were harvested. Six clavicles were scanned, enabling the development of subject-specific models and the quantification of geometrical features defining shape and cortical thickness. Bone mineral densities (BMD) were measured through double X-ray absorptiometry. Then, the general clavicle responses to dynamic compression until failure were studied. Simulations of the compression tests were carried out with the subject-specific models to assess the sensitivity of force-deflection clavicle responses to geometrical features. Clavicle fractures occurred at an average velocity of 1.41 +/- 0.4 ms(-1), with a fracture force of 1.48 +/- 0.46 kN and a deflection of 5.4 +/- 1.1 mm. A significant difference was found between male and female clavicle force values at rupture although their BMDs were not significantly different. Simulations with subject-specific models led to the conclusion that cortical bone thickness and bone shape have large effects on bone responses until failure and on fracture location. This study highlights the need for a geometrical personalization of clavicle models in order to take into account both gender discrepancies concerning clavicle shape and aging effects affecting cortical thickness.
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http://dx.doi.org/10.1016/j.jbiomech.2007.06.020DOI Listing
April 2008
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