ScienceDirect Publication: Journal of Biomechanics

The Journal of Biomechanics thanks Professor Rik Huiskes

Wed, 15 Jul 2009 19:55:57 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 15 July 2009
R., Bouhaha , Farshid, Guilak, H., Abid Kamoun , H., Ennafaa , T., Baroudi , ...

Effects of body configuration on pelvic injury in backward fall simulation using 3D finite element models of pelvis–femur–soft tissue complex

Fri, 26 Jun 2009 19:26:40 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 26 June 2009
Santanu, Majumder , Amit, Roychowdhury , Subrata, Pal

Injuries due to backward fall apart from sideways fall are a major health problem, particularly among the aged populations. The objectives of this study was to evaluate the responses to changing body configurations (angle between the trunk and impacting floor as 0°, 15°, 45° and 80°) during backward fall, based on a previously developed CT-scan-derived 3D non-linear and non-homogeneous finite element (FE) model of pelvis–femur–soft tissue complex with simplified biomechanical representation of the whole body. Under constant impact energy, these FE models evaluated the pelvic injury situations on the basis of peak impact force (7.64–16.74kN) and peak principal compressive strain...

Analysis of blood flow behaviour in custom stent grafts

Thu, 18 Jun 2009 19:30:53 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 18 June 2009
Carine, Guivier-Curien , Valerie, Deplano , Eric, Bertrand , Jean, Dominique Singland , Fabien, Koskas

Endovascular aneurysm repair (EVAR) is an attractive alternative to open surgery for treating abdominal aortic aneurysms (AAAs). However, the implantation of stent grafts into AAAs can result in post-operative complications such as stent graft migration, rupture or endoleak. EVAR has therefore been carried out only on selected patients. Stent grafts are usually standard commercial stent grafts (CSGs); however, custom made stent grafts (cmSGs) of various shapes and sizes are sometimes used to fit patients’ anatomies. In the present study, the cmSGs were specially designed and fabricated by the surgeons at the Pitié-Salpétriére hospital in Paris. Two patients carrying cmSGs with...

Reduced nucleus pulposus glycosaminoglycan content alters intervertebral disc dynamic viscoelastic mechanics

Thu, 18 Jun 2009 19:30:53 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 18 June 2009
John I., Boxberger , Amy S., Orlansky , Sounok, Sen , Dawn M., Elliott

The intervertebral disc functions over a range of dynamic loading regimes including axial loads applied across a spectrum of frequencies at varying compressive loads. Biochemical changes occurring in early degeneration, including reduced nucleus pulposus glycosaminoglycan content, may alter disc mechanical behavior and thus may contribute to the progression of degeneration. The objective of this study was to determine disc dynamic viscoelastic properties under several equilibrium loads and loading frequencies, and further, to determine how reduced nucleus glycosaminoglycan content alters dynamic mechanics. We hypothesized that (1) dynamic stiffness would be elevated with increasing equilibrium load and increasing frequency, (2) the disc...

Kinematic adjustability of unilateral external fixators for fracture reduction and alignment of axial dynamization

Tue, 16 Jun 2009 19:30:44 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 16 June 2009
Yeong-jeong, Ou

Bone fracture reduction and bone axial dynamization are important operations which effectiveness can be further enhanced by the use of a unilateral external fixator. By design, axial dynamization can be performed through reciprocating one of its translational joints. However, non-axial dynamization may occur after correcting residual fracture deformity. To explore and to maximize its full potential, the joint adjustment constraint equations for fracture reduction and alignment of axial dynamization under unilateral external fixation are derived. Their physical implications and criteria on the kinematic structure of a fixator are then established. In order to correctly make the alignment of axial dynamization...

Stress–strain behavior of mitral valve leaflets in the beating ovine heart

Tue, 16 Jun 2009 19:30:44 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 16 June 2009
Gaurav, Krishnamurthy , Akinobu, Itoh , Wolfgang, Bothe , Julia C., Swanson , Ellen, Kuhl , ...

Excised anterior mitral leaflets exhibit anisotropic, non-linear material behavior with pre-transitional stiffness ranging from 0.06 to 0.09N/mm2 and post-transitional stiffness from 2 to 9N/mm2. We used inverse finite element (FE) analysis to test, for the first time, whether the anterior mitral leaflet (AML), in vivo, exhibits similar non-linear behavior during isovolumic relaxation (IVR). Miniature radiopaque markers were sewn to the mitral annulus, AML, and papillary muscles in 8 sheep. Four-dimensional marker coordinates were obtained using biplane videofluoroscopic imaging during three consecutive cardiac cycles. A FE model of the AML was developed using marker coordinates at the end of isovolumic relaxation...

Nonlinear hierarchical multiscale modeling of cortical bone considering its nanoscale microstructure

Sat, 13 Jun 2009 19:41:06 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 13 June 2009
J., Ghanbari , R., Naghdabadi

We have used a hierarchical multiscale modeling scheme for the analysis of cortical bone considering it as a nanocomposite. This scheme consists of definition of two boundary value problems, one for macroscale, and another for microscale. The coupling between these scales is done by using the homogenization technique. At every material point in which the constitutive model is needed, a microscale boundary value problem is defined using a macroscopic kinematical quantity and solved. Using the described scheme, we have studied elastic properties of cortical bone considering its nanoscale microstructural constituents with various mineral volume fractions. Since the microstructure of bone...

A new one-DOF fully parallel mechanism for modelling passive motion at the human tibiotalar joint

Sat, 13 Jun 2009 19:41:06 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 13 June 2009
R., Franci , V., Parenti-Castelli , C., Belvedere , A., Leardini

Knowledge on how ligaments and articular surfaces guide passive motion at the human ankle joint complex is fundamental for the design of relevant surgical treatments. The paper presents a possible improvement of this knowledge by a new kinematic model of the tibiotalar articulation. Passive motion, i.e. in virtually unloaded conditions, was captured in vitro in four lower leg specimens by means of a surgical navigation system with cluster of active markers attached to the tibia and talus. The anatomical geometry of the passive structures, i.e. articular surfaces and attachment areas of the ligaments, were taken by digitisation with a pointer....

Blood damage safety of prosthetic heart valves. Shear-induced platelet activation and local flow dynamics: A fluid–structure interaction approach

Sat, 13 Jun 2009 19:41:06 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 13 June 2009
Umberto, Morbiducci , Raffaele, Ponzini , Matteo, Nobili , Diana, Massai , Franco Maria, Montevecchi , ...

Thromboembolism and the attendant risk of cardioembolic stroke remains an impediment to the development of prosthetic cardiovascular devices. In particular, altered haemodynamics are implicated in the acute blood cell damage that leads to thromboembolic complications, with platelet activation being the underlying mechanism for cardioemboli formation in blood flow past mechanical heart valves (MHVs) and other blood re-circulating devices. In this work, a new modeling paradigm for evaluating the cardioembolic risk of MHVs is described. In silico fluid–structure interaction (FSI) approach is used for providing a realistic representation of the flow through a bileaflet MHV model, and a Lagrangian analysis is...

During sideways falls proximal femur fractures initiate in the superolateral cortex: Evidence from high-speed video of simulated fractures

Sat, 13 Jun 2009 19:41:06 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 13 June 2009
Peter M., de Bakker , Sarah L., Manske , Vincent, Ebacher , Thomas R., Oxland , Peter A., Cripton , ...

Results of recent imaging studies and theoretical models suggest that the superior femoral neck is a location of local weakness due to an age-related thinning of the cortex, and thus the site of hip fracture initiation. The purpose of this study was to experimentally determine the spatial and temporal characteristics of the macroscopic failure process during a simulated hip fracture that would occur as a result of a sideways fall. Twelve fresh frozen human cadaveric femora were used in this study. The femora were fractured in an apparatus designed to simulate a fall on the greater trochanter. Image sequences of...

Effect of conformity and contact stress on wear in fixed-bearing total knee prostheses

Fri, 12 Jun 2009 19:28:57 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 12 June 2009
Alison L., Galvin , Lu, Kang , Itoro, Udofia , Louise M., Jennings , Hannah M.J., McEwen , ...

Ultra high molecular weight polyethylene (PE) remains the primary bearing surface of choice in total knee replacements (TKR). Wear is controlled by levels of cross-shear motion and contact stress. The aim of this study was to compare the wear of fixed-bearing total knee replacements with curved and flat inserts and to test the hypothesis that the flat inserts which give higher contact stresses and smaller contact areas would lead to lower levels of surface wear. A low-conforming, high contact stress knee with a low-medium level of cross shear resulted in significantly lower wear rates in comparison to a standard cruciate...

A method for the measurement of left ventricular overload for aortic valve insufficiency☆

Fri, 12 Jun 2009 19:28:57 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 12 June 2009
Brandon R., Travis , Brett L., Fowler , Francis, Robicsek

Background: The degree of left ventricular overload in patients with aortic valve insufficiency (AI) plays an important role in determining the need and timing of surgical intervention. Because hemodynamic evaluation of AI may potentially predict the effects of an insufficient valve on the ventricle before they occur, it would be useful to guide valve surgery with such a diagnostic tool. The purpose of this study was to test the performance of a new hemodynamic index based on mechanical energy loss for the measurement of the effects of insufficiency on ventricular workload. Methods and results: An intact and subsequently perforated aortic bioprosthesis was tested...

Editorial board and publication information

Thu, 11 Jun 2009 19:35:28 GMT

Publication year: 2009
Source: Journal of Biomechanics, Volume 42, Issue 9, 19 June 2009, Page IFC
[No author name available]

Three-dimensional lumbar segment kinetics of fast bowling in cricket

Thu, 11 Jun 2009 19:35:28 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 11 June 2009
René E.D., Ferdinands , Uwe, Kersting , R.N., Marshall

Cricket fast bowlers have a high incidence of serious lumbar injuries, such as lesions in the pars interarticularis. Kinematic studies have shown that bowling actions with large shoulder counter-rotation are associated with significantly higher incidences of lumbar injury. However, in bowling, there has been no calculation of the spinal loads, which are the causal mechanisms of such injuries. In this study, 21 fast bowlers (22.4±3.9 years) of premier grade level and above were tested using a three-dimensional (3D) motion analysis system. The mean ball release speed was 31.9±2.8ms−1 and ranged from 27.0 to 35.6ms−1. Kinematics and kinetics were calculated for...

Response to Letter to the Editor: Comment on “A stochastic biomechanical model for risk and risk factors of non-contact anterior cruciate ligament injuries”

Thu, 11 Jun 2009 19:35:28 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 11 June 2009
Bing, Yu , Mike, Gross , Cheng-Feng, Lin , Darin, Padua , Paul, Weinhold , ...

Design of bio-mimetic particles with enhanced vascular interaction

Thu, 11 Jun 2009 19:35:28 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 11 June 2009
Sei-Young, Lee , Mauro, Ferrari , Paolo, Decuzzi

The majority of particle-based delivery systems for the ‘smart’ administration of therapeutic and imaging agents have a spherical shape, are made by polymeric or lipid materials, have a size in the order of few hundreds of nanometers and a negligibly small relative density to aqueous solutions. In the microcirculation and deep airways of the lungs, where the creeping flow assumption holds, such small spheres move by following the flow stream lines and are not affected by external volume force fields. A delivery system should be designed to drift across the stream lines and interact repeatedly with the vessel walls, so...

Role of stability and limb support in recovery against a fall following a novel slip induced in different daily activities

Wed, 10 Jun 2009 19:35:57 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 10 June 2009
Feng, Yang , Tanvi, Bhatt , Yi-Chung, Pai

The purpose of this study was to determine whether stability and limb support play a similar role in governing slip outcome in gait-slip as in sit-to-stand-slip, and whether such prediction could also be derived based on measures of these variables during regular, unperturbed movements. Fifty-three and forty-one young subjects all took one recovery step following an unannounced, novel, forward slip induced in gait and in sit-to-stand, respectively. Logistic regression was used to predict recovery outcome based on preslip and reactive measures of stability and limb support across tasks. Following slip onset, all subjects in both tasks experienced rapid decay in...

Using two palpable measurements improves the subject-specific femoral modeling

Wed, 10 Jun 2009 19:35:57 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 10 June 2009
Weidong, Luo , Steven J., Stanhope , Frances T., Sheehan

Subject-specific musculoskeletal models are essential to biomedical research and clinical applications, such as customized joint replacement, computer-aided surgical planning, gait analysis and automated segmentation. Generating these models from CT or magnetic resonance imaging (MRI) is time and resource intensive, requiring special skills. Therefore, in many studies individual bone models are approximated by scaling a generic template. Thus, the primary goal of this study was to determine a set of clinically available parameters (palpable measures and demographic data) that could improve the prediction of femoral dimensions, as compared to predicting these variables using uniform scaling based on palpable length. Similar to...

Dynamic in vivo 3-dimensional moment arms of the individual quadriceps components

Tue, 09 Jun 2009 19:32:22 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 9 June 2009
Nicole A., Wilson , Frances T., Sheehan

The purpose of this study was to provide the first in vivo 3-dimensional (3D) measures of knee extensor moment arms, measured during dynamic volitional activity. The hypothesis was that the vastus lateralis (VL) and vastus medialis (VM) have significant off-axis moment arms compared to the central quadriceps components. After obtaining informed consent, three 3D dynamic cine phase contrast (PC) MRI sets (x,y,z velocity and anatomic images) were acquired from 22 subjects during active knee flexion and extension. Using a sagittal-oblique and two coronal-oblique imaging planes, the origins and insertions of each quadriceps muscle were identified and tracked through each time...

Effect of landing height on frontal plane kinematics, kinetics and energy dissipation at lower extremity joints

Tue, 09 Jun 2009 19:32:22 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 8 June 2009
C.H., Yeow , P.V.S., Lee , J.C.H., Goh

Lack of the necessary magnitude of energy dissipation by lower extremity joint muscles may be implicated in elevated impact stresses present during landing from greater heights. These increased stresses are experienced by supporting tissues like cartilage, ligaments and bones, thus aggravating injury risk. This study sought to investigate frontal plane kinematics, kinetics and energetics of lower extremity joints during landing from different heights. Eighteen male recreational athletes were instructed to perform drop-landing tasks from 0.3- to 0.6-m heights. Force plates and motion-capture system were used to capture ground reaction force and kinematics data, respectively. Joint moment was calculated using inverse...

Determining the three-dimensional relation between the skeletal elements of the human shoulder complex

Mon, 08 Jun 2009 19:26:06 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 7 June 2009
Jingzhou (James), Yang , Xuemei, Feng , Yujiang, Xiang , Joo H., Kim , Sudhakar, Rajulu

In this paper, we present an inverse kinematics method to determining human shoulder joint motion coupling relationship based on experimental data in the literature. This work focuses on transferring Euler-angle-based coupling equations into a relationship based on the Denavit–Hartenberg (DH) method. We use analytical inverse kinematics to achieve the transferring. For a specific posture, we can choose points on clavicle, scapula, and humerus and represent the end-effector positions based on Euler angles or DH method. For both Euler and DH systems, the end-effectors have the same Cartesian positions. Solving these equations related to end-effector positions yields DH joint angles for...

Validation of computational fluid dynamics methodology used for human upper airway flow simulations

Fri, 05 Jun 2009 19:28:49 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 5 June 2009
Goutham, Mylavarapu , Shanmugam, Murugappan , Mihai, Mihaescu , Maninder, Kalra , Sid, Khosla , ...

An anatomically accurate human upper airway model was constructed from multiple magnetic resonance imaging axial scans. This model was used to conduct detailed Computational Fluid Dynamics (CFD) simulations during expiration, to investigate the fluid flow in the airway regions where obstruction could occur. An identical physical model of the same airway was built using stereo lithography. Pressure and velocity measurements were conducted in the physical model. Both simulations and experiments were performed at a peak expiratory flow rate of 200L/min. Several different numerical approaches within the FLUENT commercial software framework were used in the simulations; unsteady Large Eddy Simulation (LES),...

Erratum to “Orientation of collagen at the osteocyte lacunae in human secondary osteons” [Journal of Biomechanics 41/16 (2008) 3426–3435]

Fri, 05 Jun 2009 19:28:49 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 5 June 2009
Maria-Grazia, Ascenzi , Jaya, Gill , Alexander, Lomovtsev

Alternative solution of virtual biomodeling based on CT-scans

Fri, 05 Jun 2009 19:28:49 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 5 June 2009
Martin, Groesel , Margit, Gfoehler , Christian, Peham

In this paper, an alternative method is presented to convert computed tomography (CT)-scans into 3D biomodels. The CT-data of an equine spine was converted into TIF format to work with it in a 2D CAD program. Then the bony structure has been marked manually with closed splines and saved as IGS files for the next procedure with 3D CAD software to create virtual biomodels of every single bone. Therefore, the different layers of the CT-scans were positioned in correct distance and then a closed surface was created to cover all spline-curves. Finally, the cover was filled up with material to...

Discretization error when using finite element models: Analysis and evaluation of an underestimated problem

Fri, 05 Jun 2009 19:28:49 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 5 June 2009
Hendrik, Schmidt , Tobias, Alber , Tim, Wehner , Robert, Blakytny , Hans-Joachim, Wilke

Mesh convergence tests are often insufficiently performed in finite element analyses. There are many parameters which may have an effect on the mesh convergence behavior. The aim of this study was to identify the influence of different parameters on the mesh convergence behavior.For this purpose we used a simplified axis-symmetrical model of a single pedicle screw flank with surrounding bone to simulate a pull-out test. In parameter studies, the flank radii and the contact conditions at the bone–screw interface were varied. These parameter studies were carried out using an implicit and explicit solver. Thereby, the convergence criteria and the number...

Functional cues in the development of osseous tooth support in the pig, Sus scrofa

Fri, 05 Jun 2009 19:28:49 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 5 June 2009
Bernhard, Croissant , T., Popowics , Ralf, Demmel , K., Yeh , Fred, Rist , ...

Alveolar bone supports teeth during chewing through a ligamentous interface with tooth roots. Although tooth loads are presumed to direct the development and adaptation of these tissues, strain distribution in the alveolar bone at different stages of tooth eruption and periodontal development is unknown. This study investigates the biomechanical effects of tooth loading on developing alveolar bone as a tooth erupts into occlusion. Mandibular segments from miniature pigs, Sus scrofa, containing M1 either erupting or in functional occlusion, were loaded in compression. Simultaneous recordings were made from rosette strain gages affixed to the lingual alveolar bone and the M2 crypt....

Mechanical properties of double-stranded DNA biolayers immobilized on microcantilever under axial compression

Thu, 04 Jun 2009 19:28:59 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 4 June 2009
Neng-Hui, Zhang , Jian-Zhong, Chen

In label-free biodetections based on microcantilever technology, double-stranded DNA (dsDNA) structures form through the linkage between probe single-stranded DNA (ssDNA) molecules immobilized on solid substrates and target ssDNA molecules in solutions. Mechanical/electrical properties of these biolayers are important factors for nanomechanical deflections of microcantilevers. In this paper, the biolayer immobilized on microcantilever is treated as a bar with a macroscopic elastic modulus on the basis of continuum mechanics viewpoints. In consideration of hydration force, screened electrostatic repulsion and conformational fluctuation in biolayers, load-deformation curves of dsDNA biolayers under axial compression are depicted with the help of the energy conservation law...

The transient relationship between pressure and volume in the pediatric pulmonary system

Wed, 03 Jun 2009 19:30:33 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 3 June 2009
Richard W., Kent , William A., Woods , Robert S., Salzar , Andrew M., Damon , Cameron R., Bass

An accurate understanding of the relationship between pulmonary pressure and volume is required for modeling pulmonary mechanics in a variety of clinical applications. In this study the experimental techniques and mathematical formulations used to characterize viscoelastic materials are applied to characterize transient pulmonary compliance in juvenile swine. Fixed volumes of air were insufflated into 5 swine and held constant for 45s while the transient decay in tracheal pressure was measured. An analytical model was developed using an optimization scheme that maximized the model fit to the experimental data over the entire time convolution. The initial injected volume was varied to...

Tibiofemoral kinematics and condylar motion during the stance phase of gait

Wed, 03 Jun 2009 19:30:33 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 3 June 2009
Michal, Kozanek , Ali, Hosseini , Fang, Liu , Samuel K., Van de Velde , Thomas J., Gill , ...

Accurate knowledge of the dynamic knee motion in-vivo is instrumental for understanding normal and pathological function of the knee joint. However, interpreting motion of the knee joint during gait in other than the sagittal plane remains controversial. In this study, we utilized the dual fluoroscopic imaging technique to investigate the six-degree-of-freedom kinematics and condylar motion of the knee during the stance phase of treadmill gait in eight healthy volunteers at a speed of 0.67m/s. We hypothesized that the 6DOF knee kinematics measured during gait will be different from those reported for non-weightbearing activities, especially with regards to the phenomenon of...

Particle deposition in a CT-scanned human lung airway

Tue, 02 Jun 2009 19:37:20 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 2 June 2009
H.Y., Luo , Y., Liu

The particle deposition in a computerized tomography (CT)-scanned human lung was numerically investigated. The five-generation airway is extracted from the trachea to segmental bronchi of a 60-year-old Chinese male patient. Computations were carried out in the flow rate range of 210–630ml/s (Reynolds number range of 1000–3000) and particle size of 2–10μm (Stokes number range of 0.0007–0.049). To count the effect of laryngeal jet on trachea inlet, the trachea was extended and modified to simulate the larynx, consequently the inlet velocity profile is biased towards the rear wall. The laryngeal jet-induced turbulence was simulated using low Reynolds number (LRN) κ–ω turbulent...

Mechanical work as predictor of force enhancement and force depression

Sun, 31 May 2009 19:31:44 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 31 May 2009
Natalia, Kosterina , Håkan, Westerblad , Anders, Eriksson

The steady-state force following active muscle shortening or stretch differs from the maximum isometric force associated with the final length. This phenomenon proves that the isometric force production is not only dependent on current muscle length and length time derivative, but depends on the preceding contraction history. Isolated extensor digitorum longus and soleus muscles from mice (NMRI strain) were used to investigate the force produced by a muscle, and some parameters hypothetically influencing this history-dependent force modification. The muscles were pre-stimulated at a fixed length, then different stretch/shortening episodes were introduced, whereafter changes of the active force were recorded while...

Knee stiffness is a major determinant of leg stiffness during maximal hopping

Sun, 31 May 2009 19:31:44 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 31 May 2009
Hiroaki, Hobara , Tetsuro, Muraoka , Kohei, Omuro , Kouki, Gomi , Masanori, Sakamoto , ...

Understanding stiffness of the lower extremities during human movement may provide important information for developing more effective training methods during sports activities. It has been reported that leg stiffness during submaximal hopping depends primarily on ankle stiffness, but the way stiffness is regulated in maximal hopping is unknown. The goal of this study was to examine the hypothesis that knee stiffness is a major determinant of leg stiffness during the maximal hopping. Ten well-trained male athletes performed two-legged hopping in place with a maximal effort. We determined leg and joint stiffness of the hip, knee, and ankle from kinetic and...

The effects of geometry on airflow in the acinar region of the human lung

Sun, 31 May 2009 19:31:44 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 31 May 2009
Haribalan, Kumar , Merryn H., Tawhai , Eric A., Hoffman , Ching-Long, Lin

Understanding flow phenomena in the pulmonary acinus is important for predicting particle transport and deposition and hence, in designing effective drug delivery strategies for the lung. In the current study, a three-dimensional honeycomb-like geometry involving a central airspace and surrounding alveoli is used to represent an alveolar duct and sacs. Numerical results predict that flow in the presence of wall motion is characterized by the presence of a developing recirculation region within the cavity and by a flow entrainment region indicative of the weak nature of interaction between duct and cavity. Under the normal breathing condition (2.5s) and volumetric expansion...

Effects of stress shielding and subsequent restressing on mechanical properties of regenerated and residual tissues in rabbit patellar tendon after resection of its central one-third

Sun, 31 May 2009 19:31:44 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 31 May 2009
Eijiro, Maeda , Hiroyuki, Asanuma , Hitoshi, Noguchi , Harukazu, Tohyama , Kazunori, Yasuda , ...

Central third of patellar tendon (PT) is used as an autograft for anterior cruciate ligament (ACL) reconstruction. Previous studies investigated temporal changes in material properties of healing tissues in PT after resection of the central third. However, no study has been performed on effects of stress shielding (SS) and restressing (RS) on the properties of healing tissues. The present study hypothesised that SS adversely affects the mechanical integrity of healing tissues, which is recovered by subsequent RS. An entire rectangular defect was created in the central third of rabbit PT. Operated PTs were subjected to either SS or no stress...

Validation of a fluid–structure interaction numerical model for predicting flow transients in arteries

Sat, 30 May 2009 19:25:15 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 30 May 2009
V., Kanyanta , A., Ivankovic , A., Karac

Fluid–structure interaction (FSI) numerical models are now widely used in predicting blood flow transients. This is because of the importance of the interaction between the flowing blood and the deforming arterial wall to blood flow behaviour. Unfortunately, most of these FSI models lack rigorous validation and, thus, cannot guarantee the accuracy of their predictions. This paper presents the comprehensive validation of a two-way coupled FSI numerical model, developed to predict flow transients in compliant conduits such as arteries. The model is validated using analytical solutions and experiments conducted on polyurethane mock artery. Flow parameters such as pressure and axial stress...

Comment on “Contributions of the individual ankle plantar flexors to support, forward progression and swing initiation during walking” (Neptune et al., 2001) and “Muscle mechanical work requirements during normal walking: The energetic cost of raising the body's center-of-mass is significant” (Neptune et al., 2004)

Sat, 30 May 2009 19:25:15 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 30 May 2009
Arthur D., Kuo , J., Maxwell Donelan

Spatial patterning of cell proliferation and differentiation depends on mechanical stress magnitude

Sat, 30 May 2009 19:25:15 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 30 May 2009
Bin, Li , Fang, Li , Kathleen M., Puskar , James H-C., Wang

Mechanical stress has been proposed as a major regulator of tissue morphogenesis; however, it remains unclear what is the exact mechanical signal that leads to local tissue pattern formation. We explored this question by using a micropatterned cell aggregate model in which NIH 3T3 fibroblasts were cultured on micropatterned adhesive islands and formed cell aggregates (or “cell islands”) of triangular, square, and circular shapes. We found that the cell islands generated high levels of mechanical stresses at their perimeters compared to their inner regions. Regardless of the shape of cell islands, the mechanical stress patterns corresponded to both cell proliferation...

A virtual model of the bench press exercise

Sat, 30 May 2009 19:25:15 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 30 May 2009
Abderrahmane, Rahmani , Olivier, Rambaud , Muriel, Bourdin , Jean-Pierre, Mariot

The objective of this study was to design and validate a three degrees of freedom model in the sagittal plane for the bench press exercise. The mechanical model was based on rigid segments connected by revolute and prismatic pairs, which enabled a kinematic approach and global force estimation. The method requires only three simple measurements: (i) horizontal position of the hand (x0); (ii) vertical displacement of the barbell (Z) and (iii) elbow angle (θ). Eight adult male throwers performed maximal concentric bench press exercises against different masses. The kinematic results showed that the vertical displacement of each segment and the...

Erratum to “Influence of surface penetration on measured fluid force on a hand model” [Journal of Biomechanics 41 (2008) 3502–3505]

Sat, 30 May 2009 19:25:15 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 30 May 2009
Shigetada, Kudo , Ross, Vennell , Barry, Wilson , Neil, Waddell , Yohei, Sato

Finite-element simulation of flexor digitorum longus or flexor digitorum brevis tendon transfer for the treatment of claw toe deformity

Fri, 29 May 2009 19:27:52 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 29 May 2009
Alberto, García-González , Javier, Bayod , Juan Carlos, Prados-Frutos , Marta, Losa-Iglesias , Kevin T., Jules , ...

Claw toe deformity sometimes leads to dorsiflexion of the metatarsophalangeal joint (MPJ) and plantar flexion of the proximal (PIPJ) and distal interphalangeal (DIPJ) joints. Flexor digitorum longus tendon transfer (FDL) is currently the gold standard for the correction of this problem. Transfer of the flexor digitorum brevis (FDB) has been recently proposed as an alternative method to treat such deformity. The aim of this work is to compare the biomechanical outcome of these two methods by means of finite-element simulation. The results show that the reduction in the dorsal displacement of the proximal phalanx (PP) for the second and third...

A 3D finite element model of anterior vaginal wall support to evaluate mechanisms underlying cystocele formation

Fri, 29 May 2009 19:27:52 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 29 May 2009
Luyun, Chen , James A., Ashton-Miller , John O.L., DeLancey

Objectives: To develop a 3D computer model of the anterior vaginal wall and its supports, validate that model, and then use it to determine the combinations of muscle and connective tissue impairments that result in cystocele formation, as observed on dynamic magnetic resonance imaging (MRI). Methods: A subject-specific 3D model of the anterior vaginal wall and its supports were developed based on MRI geometry from a healthy nulliparous woman. It included simplified representations of the anterior vaginal wall, levator muscle, cardinal and uterosacral ligaments, arcus tendineus fascia pelvis and levator ani, paravaginal attachments, and the posterior compartment. This model was then imported into...

Comment on “A stochastic biomechanical model for risk and risk factors of non-contact anterior cruciate ligament injuries”

Fri, 29 May 2009 19:27:52 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 29 May 2009
Antonie J., van den Bogert , Scott G., McLean

Iliotibial band tension affects patellofemoral and tibiofemoral kinematics

Thu, 28 May 2009 19:31:07 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 28 May 2009
Azhar M., Merican , Andrew A., Amis

The iliotibial band (ITB) has an important role in knee mechanics and tightness can cause patellofemoral maltracking. This study investigated the effects of increasing ITB tension on knee kinematics. Nine fresh-frozen cadaveric knees had the components of the quadriceps loaded with 175N. A Polaris optical tracking system was used to acquire joint kinematics during extension from 100° to 0° flexion. This was repeated after the following ITB loads: 30, 60 and 90N. There was no change with 30N load for patellar translation. On average, at 60 and 90N, the patella translated laterally by 0.8 and 1.4mm in the mid flexion...

Patellofemoral interactions in walking, stair ascent, and stair descent using a virtual patella model

Thu, 28 May 2009 19:31:07 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 28 May 2009
Nadine, Ngayila , Jeffrey E., Bischoff , Michel, Botineau , Justin S., Hertzler , Michel, Baudu , ...

Restoration of normal patella kinematics is an important clinical outcome of total knee arthroplasty. Failure of the patella within total knee systems has been documented and, upon occurrence, often necessitates revision surgery. It is thus important to understand patella mechanics following implantation, subject to load states that are typically realized during walking and other gaits. Here, a computational model of the patella is developed and used to examine the effects of walking, stair ascent, and stair descent on the development of stress and contact pressure in the patella throughout the gait cycle. Motion of the patella was governed by a...

Assessment of blood volume flow in slightly curved arteries from a single velocity profile

Thu, 28 May 2009 19:31:07 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 28 May 2009
C.A.D., Leguy , E.M.H., Bosboom , A.P.G., Hoeks , F.N., van de Vosse

Non-invasive estimation of arterial blood volume flow (BVF) has become a central issue in assessment of cardiovascular risk. Poiseuille and Womersley approaches are commonly used to assess the BVF from centerline velocity, but both methods neglect the influence of curvature. Based on the assumption that the velocity in curved tubes as function of the circumferential position for a given radial position can be approximated by a cosine, the BVF can also be estimated by averaging velocities at opposite radial positions, referred to as the cosine θ model (CTM).This study investigates the accuracy of BVF estimation in slightly curved arteries for...

Modeling of the mechanical function of the human gastroesophageal junction using an anatomically realistic three-dimensional model

Thu, 28 May 2009 19:31:07 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 28 May 2009
R., Yassi , L.K., Cheng , V., Rajagopal , M.P., Nash , J.A., Windsor , ...

The aim of this study was to combine the anatomy and physiology of the human gastroesophageal junction (the junction between the esophagus and the stomach) into a unified computer model. A three-dimensional (3D) computer model of the gastroesophageal junction was created using cross-sectional images from a human cadaver. The governing equations of finite deformation elasticity were incorporated into the 3D model. The model was used to predict the intraluminal pressure values (pressure inside the junction) due to the muscle contraction of the gastroesophageal junction and the effects of the surrounding structures. The intraluminal pressure results obtained from the 3D model...

Nanostructure and nanomechanics analysis of lymphocyte using AFM: From resting, activated to apoptosis

Thu, 28 May 2009 19:31:07 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 27 May 2009
Mingqian, Hu , Jiongkun, Wang , Hongxia, Zhao , Shisong, Dong , Jiye, Cai

The ultrastructural and mechanical properties of single resting, activated and apoptosis lymphocyte have been investigated by atomic force microscopy (AFM). Using topographic imaging, we showed that the surface of the resting lymphocyte is smooth, while lymphocyte activation and apoptosis are often accompanied by changes in cell morphology. The apoptosis lymphocyte is rougher than those of the two other morphotypes, and coated with many big particles. Using spatially resolved force–distance curves, we found that the valve of the activated lymphocyte is about two to three times stiffer (Young's modulus of ∼20kPa) than those of the two other morphotypes (5–11kPa). These results...

Author's response to comment on “Contributions of the individual ankle plantar flexors to support, forward progression and swing initiation during walking” (Neptune et al., 2001) and “Muscle mechanical work requirements during normal walking: The energetic cost of raising the body's center-of-mass is significant” (Neptune et al., 2004)

Thu, 28 May 2009 19:31:07 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 27 May 2009
Richard R., Neptune , Felix E., Zajac , Steven A., Kautz

Predicting maximum eccentric strength from surface EMG measurements

Sat, 23 May 2009 20:02:35 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 23 May 2009
Brice, Bathellier , Matthew T.G., Pain , Derek L., Buhl , Stephanie E., Forrester, Riccardo, Accolla , ...

The origin of the well-documented discrepancy between maximum voluntary and in vitro tetanic eccentric strength has yet to be fully understood. This study aimed to determine whether surface EMG measurements can be used to reproduce the in vitro tetanic force–velocity relationship from maximum voluntary contractions. Five subjects performed maximal knee extensions over a range of eccentric and concentric velocities on an isovelocity dynamometer whilst EMG from the quadriceps were recorded. Maximum voluntary (MVC) force–length–velocity data were estimated from the dynamometer measurements and a muscle model. Normalised amplitude–length–velocity data were obtained from the EMG signals. Dividing the MVC forces by the...

Characterization of bone-implant fixation using modal analysis: Application to a press-fit implant model

Sat, 23 May 2009 20:02:35 GMT

Publication year: 2009
Source: Journal of Biomechanics, In Press, Corrected Proof, Available online 22 May 2009
Jacob, Berry , P., Swider , William C., Krause , G., Guérin , Ronald L., Davis, ...

Orthopaedic implant fixation is strongly dependant upon the effective mechanical properties of newly formed tissue. In this study, we evaluated the potential of modal analysis to derive viscoelastic properties of periprosthetic tissue. We hypothesized that Young's modulus and loss factor could be obtained by a combined theoretical, computational and experimental modal analysis approach. This procedure was applied to ex vivo specimens from a cylindrical experimental implant placed in cancellous bone in an unloaded press-fit configuration, obtained after a four week observation period. Four sections each from seven textured titanium implants were investigated. The first resonant frequency and loss factor were...