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Editorial board and publication informationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
(Source: Journal of Biomechanics)
Source: Journal of Biomechanics - November 2, 2009 Category: Biomedical Science Source Type: journals

Local bone formation due to combined mechanical loading and intermittent hPTH-(1-34) treatment and its correlation to mechanical signal distributionsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: We evaluated the local response of cortical bone in the rat tibia due to combined treatment with synthetic parathyroid hormone, hPTH-(1-34), and mechanical stimulation by four-point bending. Forty-eight female retired breeder Sprague-Dawley rats were divided into six groups. Mechanically stimulated animals included the following groups: (1) Bend+PTH, (2) Sham+PTH, (3) Bend+Vehicle, (4) Sham+Vehicle. Non-mechanically stimulated animals included a (5) Control group that received neither loading nor injections, and a (6) PTH group that received only hPTH-(1-34) injections. The right limbs of mechanically loaded anim...
Source: Journal of Biomechanics - September 28, 2009 Category: Biomedical Science Authors: M.D. Roberts, T.J. Santner, R.T. Hart Tags: Papers Source Type: journals

Call for Abstracts 17th Congress of the European Society of Biomechanics Edinburgh, Scotland, UK, July 5th – July 8th, 2010Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
(Source: Journal of Biomechanics)
Source: Journal of Biomechanics - September 24, 2009 Category: Biomedical Science Tags: Announcement Source Type: journals

Mixing and matching in ceramic-on-metal hip arthroplasty: An in-vitro hip simulator studyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study was aimed at characterizing the wear behaviour of new hybrid ceramic-on-metal bearings. In particular, this study investigated the wear behaviour of ceramic-on-metal hip components (three different diameters configurations: 28, 32 and 36mm), not specifically proposed to be coupled, in order to compare them with ceramic-on-ceramic, which is considered to be the gold standard for wear resistance. For this purpose, the weight loss over a standard wear simulation was monitored. Moreover, scanning electronic microscope observations were used to verify if any carbides removal, for the metallic components, triggered we...
Source: Journal of Biomechanics - September 16, 2009 Category: Biomedical Science Authors: Saverio Affatato, Michele Spinelli, Stefano Squarzoni, Francesco Traina, Aldo Toni Tags: Papers Source Type: journals

Nanotribological characterization of tooth enamel rod affected by surface treatmentEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Tooth enamel is a hybrid organic–inorganic bionanocomposite comprised predominantly of enamel rods. Understanding the effects of anti-caries treatment on the biomechanical properties of these rods is essential in developing effective caries prevention strategies. Calcium fluoride-like deposits play an important role in caries prevention and their nanotribological properties have a direct effect upon their long-term effectiveness. Accordingly, this study utilizes a variety of techniques, namely nanoindentation, nanoscratch tests, nanowear tests and atomic force microscopy (AFM), to characterize the mechanical an...
Source: Journal of Biomechanics - September 13, 2009 Category: Biomedical Science Authors: Yeau-Ren Y.-R. Jeng, Tsung-Ting T.-T. Lin, Dar-Bin D.-B. Shieh Tags: Papers Source Type: journals

Oxidized low-density lipoprotein (Ox-LDL) impacts on erythrocyte viscoelasticity and its molecular mechanismEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, erythrocyte deformability and its membrane proteins after Ox-LDL incubations are investigated by micropipette aspiration, thiol radical measurement, and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Results show that Ox-LDL incubation reduces the erythrocyte deformability, decreases free thiol radical contents in erythrocytes, and induces the cross-linking among membrane proteins. SDS-PAGE analysis reveals a high molecular weight (HMW) complex as well as new bands between spectrins and band 3 and reduced ratios between band 3 and other major membrane skeletal proteins. Analyses indic...
Source: Journal of Biomechanics - September 10, 2009 Category: Biomedical Science Authors: Xiang Wang, Li Yang, Yao Liu, Wei Gao, Weiyan Peng, K.-L. Paul Sung, Lanping Amy Sung Tags: Papers Source Type: journals

Editorial board and publication informationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
(Source: Journal of Biomechanics)
Source: Journal of Biomechanics - September 7, 2009 Category: Biomedical Science Source Type: journals

Development and design of a novel loading device for the investigation of bone adaptation around immediately loaded dental implants using the reindeer antler as implant bedEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: The assessment of the behavior of immediately loaded dental implants using biomechanical methods is of particular importance. The primary goal of this investigation is to optimize the function of the implants to serve for immediate loading. Animal experiments on reindeer antlers as a novel animal model will serve for investigation of the bone remodeling processes in the implant bed. The main interest is directed towards the time and loading-dependant behavior of the antler tissue around the implants. The aim and scope of this work was to design an autonomous loading device that has the ability to load an inserted...
Source: Journal of Biomechanics - September 6, 2009 Category: Biomedical Science Authors: Alireza Rahimi, Reinhard Klein, Ludger Keilig, Marcus Abboud, Gerhard Wahl, Christoph Bourauel Tags: Short Communications Source Type: journals

Verification of predicted specimen-specific natural and implanted patellofemoral kinematics during simulated deep knee bendEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Verified computational models represent an efficient method for studying the relationship between articular geometry, soft-tissue constraint, and patellofemoral (PF) mechanics. The current study was performed to evaluate an explicit finite element (FE) modeling approach for predicting PF kinematics in the natural and implanted knee. Experimental three-dimensional kinematic data were collected on four healthy cadaver specimens in their natural state and after total knee replacement in the Kansas knee simulator during a simulated deep knee bend activity. Specimen-specific FE models were created from medical images ...
Source: Journal of Biomechanics - August 31, 2009 Category: Biomedical Science Authors: Mark A. Baldwin, Chadd Clary, Lorin P. Maletsky, Paul J. Rullkoetter Tags: Papers Source Type: journals

Mapping ligament insertion sites onto bone surfaces in knee by co-registration of CT and digitization dataEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: This paper describes a new methodology that enables mapping of the ligament insertion sites onto bone surfaces in the knee joint by co-registration of the data acquired using digitization and computed tomography (CT). Local coordinate systems on the distal femur and proximal tibia were established by three spherical fiducial markers rigidly affixed to each bone. The fiducial marker centroid locations were identified by a least-squares sphere-fitting algorithm. An optimization correction procedure was proposed to mitigate the effect of the target registration error (TRE) on the alignment of coordinate systems for ...
Source: Journal of Biomechanics - August 27, 2009 Category: Biomedical Science Authors: Kang Li, Madelyn O’Farrell, Daniel Martin, Sebastian Kopf, Christopher Harner, Xudong Zhang Tags: Short Communications Source Type: journals

Comparison of global and joint-to-joint methods for estimating the hip joint load and the muscle forces during walkingEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: A three-dimensional musculoskeletal model of the lower limb was developed to study the influence of biarticular muscles on the muscle force distribution and joint loads during walking. A complete walking cycle was recorded for 9 healthy subjects using the standard optoelectronic motion tracking system. Ground contact forces were also measured using a 6-axes force plate. Inverse dynamics was used to compute net joint reactions (forces and torques) in the lower limb. A static optimization method was then used to estimate muscle forces. Two different approaches were used: in the first one named global method, the bi...
Source: Journal of Biomechanics - August 24, 2009 Category: Biomedical Science Authors: F. Fraysse, R. Dumas, L. Cheze, X. Wang Tags: Papers Source Type: journals

Finding and defining the ideal patellar resection plane in total knee arthroplastyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The objectives of this study were to: determine the intra- and inter-surgeon repeatability of two radiographic resection definitions (medial–divot, MD, and medial–lateral extents, MLE); calculate two additional definitions from the radiographic patellar circumferences (parallel to the anterior surface, ANT, and perpendicular to the anteroposterior tangent points, PERP); compare the clinical resection line to the previous four definitions before and after introducing the MD method clinically; and identify distinguishing features of patellae with better vs. worse resection angles. We hypothesized that the MD method would...
Source: Journal of Biomechanics - August 24, 2009 Category: Biomedical Science Authors: C. Anglin, C. Fu, A.J. Hodgson, N. Helmy, N.V. Greidanus, B.A. Masri Tags: Papers Source Type: journals

Heterogeneity of yield strain in low-density versus high-density human trabecular boneEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Understanding the off-axis behavior of trabecular yield strains may lend unique insight into the etiology of fractures since yield strains provide measures of failure independent of elastic behavior. We sought to address anisotropy of trabecular yield strains while accounting for variations in both density and anatomic site and to determine the mechanisms governing this behavior. Cylindrical specimens were cored from vertebral bodies (n=22, BV/TV=0.11±0.02) and femoral necks (n=28, BV/TV=0.22±0.06) with the principal trabecular orientation either aligned along the cylinder axis (on-axis, n=22) or at an oblique ...
Source: Journal of Biomechanics - August 24, 2009 Category: Biomedical Science Authors: Grant Bevill, Farhad Farhamand, Tony M. Keaveny Tags: Papers Source Type: journals

Influence of knee alignment on quadriceps cross-sectional areaEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we compared the ratios of the individual muscles composing the quadriceps between subjects with different knee alignments using magnetic resonance (MR) imaging.A total of 18 healthy males were examined: 6 normal knees (age, 23.0±0.6yr; femorotibial angle (FTA), 176.8±0.4°), 6 genu varum (age, 21.8±2.9 yr; FTA, 181.7±2.6°) and 6 genu valgum (age, 21.0±1.6yr; FTA, 172.3±1.5°). The cross-sectional areas (CSAs) of quadriceps muscles were obtained by MR imaging of the entire left thigh. The CSAs of the vastus lateralis (VL), rectus femoris (RF), vastus medialis (VM) and vastus intermedius (VI) muscles we...
Source: Journal of Biomechanics - August 20, 2009 Category: Biomedical Science Authors: Akitoshi Sogabe, Naoki Mukai, Shunpei Miyakawa, Noboru Mesaki, Kazuaki Maeda, Tadashi Yamamoto, Philip M. Gallagher, Matt Schrager, Andrew C. Fry Tags: Papers Source Type: journals

Changes to the viscoelastic properties of brain tissue after traumatic axonal injuryEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: While it has been shown that repetitive mild brain injuries can cause cumulative damage to the brain, changes to the mechanical properties of brain tissue at large deformations were also noted in the literature. The goal of this study was to show that the viscoelastic properties of brain tissue significantly change after traumatic axonal injury (TAI). An impact acceleration model was used to create TAI in the rat brainstem which was quantified with an immunohistochemistry technique at the ponto-medullary junction (PmJ) and pyramidal decussation (PDx). The viscoelastic properties at these two points with and witho...
Source: Journal of Biomechanics - August 20, 2009 Category: Biomedical Science Authors: Mehdi Shafieian, Kurosh K. Darvish, James R. Stone Tags: Papers Source Type: journals

Corrigendum to “Biomechanical effect of mineral heterogeneity in trabecular bone” [J. Biomech. 41 (2008) 2793–2798]Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The authors regret that in the above article was printed incorrectly. It is now reproduced correctly, below. (Source: Journal of Biomechanics)
Source: Journal of Biomechanics - August 17, 2009 Category: Biomedical Science Authors: G.A.P. Renders, L. Mulder, G.E.J. Langenbach, L.J. van Ruijven, T.M.G.J. van Eijden Tags: Corrigendum Source Type: journals

The consistency of maximum running speed measurements in humans using a feedback-controlled treadmill, and a comparison with maximum attainable speed during overground locomotionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Consistent measurement of maximum running speed overground is problematic due to the difficulty in precise, continual measurement of speed, and the substantial workload in accelerating the body promoting the onset of fatigue. Treadmills remove the requirement for acceleration which enables more repeats. They also allow experiments to be carried out in controlled environments and where space is limited, but they usually depend on manual and subjective speed control. Here we used a draw-wire position sensor and a proportional–derivative (PD) controller to automatically adjust treadmill belt speed of a large equin...
Source: Journal of Biomechanics - August 17, 2009 Category: Biomedical Science Authors: Mark V. Bowtell, Huiling Tan, Alan M. Wilson Tags: Papers Source Type: journals

Fatigue creep damage at the cement–bone interface: An experimental and a micro-mechanical finite element studyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study shows the additional value of FEA of the cement–bone interface relative to experimental studies and can therefore be used to optimize its mechanical properties. (Source: Journal of Biomechanics)
Source: Journal of Biomechanics - August 17, 2009 Category: Biomedical Science Authors: Daan Waanders, Dennis Janssen, Mark A. Miller, Kenneth A. Mann, Nico Verdonschot Tags: Papers Source Type: journals

Gait posture estimation using wearable acceleration and gyro sensorsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: A method for gait analysis using wearable acceleration sensors and gyro sensors is proposed in this work. The volunteers wore sensor units that included a tri-axis acceleration sensor and three single axis gyro sensors. The angular velocity data measured by the gyro sensors were used to estimate the translational acceleration in the gait analysis. The translational acceleration was then subtracted from the acceleration sensor measurements to obtain the gravitational acceleration, giving the orientation of the lower limb segments. Segment orientation along with body measurements were used to obtain the positions o...
Source: Journal of Biomechanics - August 17, 2009 Category: Biomedical Science Authors: Ryo Takeda, Shigeru Tadano, Akiko Natorigawa, Masahiro Todoh, Satoshi Yoshinari Tags: Papers Source Type: journals

Footfall dynamics for racewalkers and runners barefoot on compliant surfacesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: The main purpose of this study is to investigate the role of footfall surface compliance on the physical parameters affecting barefoot racewalkers and runners. These parameters are identified using a new inverted pendulum body model with a forward moving foot pivot. Model correlations of footfall loads measured for four compliant surface mats showed leg–foot compression stiffness for both gaits were in the range of 10.8–12.9kN/m, with the initial stiffness spikes in the range of 6.5–52kN/m. The average leg damping factor was about 0.6% for racewalkers and 6% for runners. For both gaits there was negative le...
Source: Journal of Biomechanics - August 17, 2009 Category: Biomedical Science Authors: James F. Wilson, Rodger D. Rochelle Tags: Papers Source Type: journals

Bilateral knee osteoarthritis does not affect inter-joint coordination in older adults with gait deviations during obstacle-crossingEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Fifteen elderly subjects with bilateral medial knee osteoarthritis (OA) and 15 healthy elderly subjects walked and crossed obstacles with heights of 10%, 20%, and 30% of their leg lengths while sagittal angles and angular velocities of each joint were measured and their phase angles (ϕ) calculated. Continuous relative phase (CRP) were also obtained, i.e., ϕhip−knee and ϕknee−ankle. The standard deviations of the CRP curve points were averaged to obtain deviation phase (DP) values for the stance and swing phases. Significant differences between the OA and control groups were found in several of the peak and...
Source: Journal of Biomechanics - August 16, 2009 Category: Biomedical Science Authors: Ting-Ming T.-M. Wang, Hsiao-Ching H.-C. Yen, Tung-Wu T.-W. Lu, Hao-Ling H.-L. Chen, Chu-Fen C.-F. Chang, Yen-Hung Y.-H. Liu, Wen-Chi W.-C. Tsai Tags: Papers Source Type: journals

How do spinal segments move?Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Conclusions: Generally joints alternate in guidance. Lumbar segments: in axial rotation and lateral-flexion parametrical control of IHA-position and IHA-migration by axial preload position. Cervical segments: kinematical coupling between axial rotation and lateral-flexion.The IHA-migration guided by the joints should be taken into account in the design of non-fusion implants. FE-calculations of spinal mechanics and kinematics should be based on detailed data of curvature morphology of the articulating surfaces of the joint facets. (Source: Journal of Biomechanics)
Source: Journal of Biomechanics - August 16, 2009 Category: Biomedical Science Authors: M.M. Wachowski, M. Mansour, C. Lee, A. Ackenhausen, S. Spiering, J. Fanghänel, C. Dumont, D. Kubein-Meesenburg, H. Nägerl Tags: Papers Source Type: journals

Wearing shoes increasing dorsiflexion improves short-term but not long-term balance control in young healthy adultsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Wearing sport shoes inducing ankle dorsiflexion has been shown to alter the biomechanical specificities of the stretched muscles. The possible effect over the short and long term upon the sensorial capacities induced by such stretching has not been addressed yet. Fourteen healthy individuals were involved to assess the proprioceptive repercussion and their effects upon postural control strategies. Postural control and proprioceptive assessment were measured twice: when receiving sport shoes inducing ankle dorsiflexion and 18 days later. Proprioceptive effects were assessed using an ad-hoc device through which the...
Source: Journal of Biomechanics - August 16, 2009 Category: Biomedical Science Authors: P.R. Rougier, F. Lachaume, J. Bourse, M. Rogeon, A. Monti, S.C. Regueme Tags: Papers Source Type: journals

A mechanical model of the gating spring mechanism of stereociliaEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: The stereocilium is the basic sensory unit of nature's mechanotransducers, which include the cochlear and vestibular organs. In noisy environments, stereocilia display high sensitivity to miniscule stimuli, effectively dealing with a situation that is a design challenge in micro systems. The gating spring hypothesis suggests that the mechanical stiffness of stereocilia bundle is softened by tip-link gating in combination with active bundle movement, contributing to the nonlinear amplification of miniscule stimuli. To demonstrate that the amplification is induced mechanically by the gating as hypothesized, we deve...
Source: Journal of Biomechanics - August 16, 2009 Category: Biomedical Science Authors: Koeun Lim, Sukyung Park Tags: Papers Source Type: journals

Can sulci protect the brain from traumatic injury?Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: The influence of sulci in dynamic finite element simulations of the human head has been investigated. First, a detailed 3D FE model was constructed based on an MRI scan of a human head. A second model with a smoothed brain surface was created based on the same MRI scan as the first FE model. These models were validated against experimental data to confirm their human-like dynamic responses during impact. The validated FE models were subjected to several acceleration impulses and the maximum principle strain and strain rate in the brain were analyzed. The results suggested that the inclusion of sulci should be con...
Source: Journal of Biomechanics - August 16, 2009 Category: Biomedical Science Authors: Johnson Ho, Svein Kleiven Tags: Papers Source Type: journals

Synergetic microorganismic convection generated by Opercularia asymmetrica ciliates living in a colony as effective fluid transport on the micro-scaleEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Ciliates, being one of the main substrates in granular activated sludge (GAS) formation, are treated as a major factor in granulation process. Cilia beats of Opercularia asymmetrica provide a continuous nutrient flux, enhancing the colonization of bacteria on Peritrichia stalks. Given that the ciliates tend to live in colonies, the main focus of the present work was an analysis and comparison of the flow effects induced by a single ciliate and by a colony. Investigations of the flow generated by Opercularia asymmetrica were carried out using micro-particle image velocimetry with biocompatible seeding. The results...
Source: Journal of Biomechanics - August 12, 2009 Category: Biomedical Science Authors: Bogumila E. Zima-Kulisiewicz, Antonio Delgado Tags: Papers Source Type: journals

A study of the viability of obtaining a generic animation of the foot while walking for the virtual testing of footwear using dorsal pressuresEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Establishing the appropriate pressure exerted by the shoe upper over the foot surface is fundamental for the design of specific footwear, although measuring the dorsal pressures can also provide important additional information. In previous works, a virtual simulator to perform studies of comfort and functionality in CAD footwear design was presented. This paper describes the procedure carried out to obtain the foot animations used in this simulator. The virtual feet used in the simulator are feet without a standard form scanned in a static way. Their movements are rebuilt from the register of movements of severa...
Source: Journal of Biomechanics - August 12, 2009 Category: Biomedical Science Authors: M.J. Rupérez, C. Monserrat, M. Alcañíz Tags: Papers Source Type: journals

Tolerance of the skull to blunt ballistic temporo-parietal impactEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Less-lethal ballistic projectiles are used by police personnel to temporarily incapacitate suspects. While the frequency of these impacts to the head is low, they account for more serious injuries than impacts to any other body region. As a result, there is an urgent need to assess the tolerance of the head to such impacts. The focus of this study was to investigate the tolerance of the temporo-parietal skull to blunt ballistic impact and establish injury criteria for risk assessment. Seven unembalmed isolated cadaver heads were subjected to fourteen impacts. Specimens were instrumented with a nine-accelerometer ...
Source: Journal of Biomechanics - August 12, 2009 Category: Biomedical Science Authors: David Raymond, Chris Van Ee, Gregory Crawford, Cynthia Bir Tags: Papers Source Type: journals

Modeling aqueous humor collection from the human eyeEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Glaucoma is a common cause of blindness. Studies of this disease can involve collection of aqueous humor (AH) fluid from eyes of patients undergoing surgery, which involves aspirating a small fluid volume from the anterior region of the eye through a fine-bore needle. Unfortunately, the composition of the AH is spatially non-uniform in the eye, and thus the composition of the aspirated fluid is uncertain. Our goal was to numerically simulate the AH aspiration process to determine where the aspirated fluid was being collected from and thus gain insight into the composition of the collected fluid.A 3D computational...
Source: Journal of Biomechanics - August 12, 2009 Category: Biomedical Science Authors: Konstantinos Kapnisis, Mark Van Doormaal, C. Ross Ethier Tags: Papers Source Type: journals

An application of principal component analysis for lower body kinematics between loaded and unloaded walkingEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study applied principal component analysis (PCA) to motion capture data in order to analyze the lower body gait patterns for four loading conditions: normal weight unloaded, normal weight loaded, overweight unloaded and overweight loaded.PCA has been shown to be a powerful tool for analyzing complex gait data. In this analysis, it is shown that in order to quantify the effects of external loads and/or for both normal weight and overweight subjects, the first principal component (PC1) is needed. For the work in this paper, PCs were generated from lower body joint angle data. The PC1 of the hip angle and PC1 of the ankl...
Source: Journal of Biomechanics - August 11, 2009 Category: Biomedical Science Authors: Minhyung Lee, Michael Roan, Benjamin Smith Tags: Papers Source Type: journals

Editorial board and publication informationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
(Source: Journal of Biomechanics)
Source: Journal of Biomechanics - August 11, 2009 Category: Biomedical Science Source Type: journals

Describing force-patterns: A method for an analytic classification using the example of sledge jumpsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: To recognise and classify movement patterns correctly can be a difficult task. Nevertheless, movement analysts are working on it on a daily basis. Therefore, we have developed and evaluated a method to do the classification by using contact forces during hopping in a sledge system. Here, experiments showed that reaction-forces of different subjects on a sliding sledge could be divided into four major types. These types are symmetric single-modal (type I), positive mono-modal (type II), negative mono-modal (type III), and multi-modal associated with plateau formation (type IV).Up until now, an exact determination ...
Source: Journal of Biomechanics - August 10, 2009 Category: Biomedical Science Authors: Thomas Ertelt, Reinhard Blickhan Tags: Short Communications Source Type: journals

Stress deprivation from the patellar tendon induces apoptosis of fibroblasts in vivo with activation of mitogen-activated protein kinasesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study was conducted to test a hypothesis that complete stress deprivation of the patellar tendon induces fibroblast apoptosis in vivo with activation of Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38) within 24h after treatment. A total of 35 mature rabbits were divided into stress-shielded (n=15), sham-operated (n=15), and control (n=5) groups. To completely shield the patellar tendon from stress, we used an established surgical method. Animals were sacrificed at 24h, and 2, 4, 7, and 14 days after the treatment. Tendon specimens underwent TUNEL assay and immunohistological examinations of ...
Source: Journal of Biomechanics - August 10, 2009 Category: Biomedical Science Authors: Hideyuki Kawabata, Taro Katsura, Eiji Kondo, Nobuto Kitamura, Shin Miyatake, Yoshie Tanabe, Takao Setoguchi, Setsuro Komiya, Kazunori Yasuda Tags: Short Communications Source Type: journals

Effect of muscle model parameter scaling for isometric plantar flexion torque predictionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: This paper uses a EMG-driven Hill-type muscle model to estimate individual muscle forces of the triceps surae in isometric plantar flexion contractions. A uniform group of 20 young physical-active adult males was instructed to follow a specific contraction protocol with low (20%MVC) and medium-high (60%MVC) contractions, separated by relaxing intervals. The torque calculated by summing the individual muscle forces multiplied by the respective moment arms was compared to the torque measured by a dynamometer. Musculoskeletal parameters from the literature were used. Then, three different “correction factors” or...
Source: Journal of Biomechanics - August 10, 2009 Category: Biomedical Science Authors: Luciano Luporini Menegaldo, Liliam Fernandes de Oliveira Tags: Papers Source Type: journals

Regulatory effects of biomechanical strain on the insulin-like growth factor system in human periodontal cellsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: During mastication, dental trauma and functional dental habits the tissues that surround and support the teeth, i.e. the periodontium, are subject to complex biomechanical forces. The exact mechanisms mediating the anabolic and catabolic biomechanical effects on the periodontium are yet poorly understood. Therefore, the objective of this in-vitro study was to determine if continuous tensile strain (CTS) regulates the synthesis of components of the insulin-like growth factor (IGF) system in human periodontal ligament (PDL) cells. PDL cells from six donors were phenotyped, seeded on collagen type-I coated silicone ...
Source: Journal of Biomechanics - August 10, 2009 Category: Biomedical Science Authors: Birgit Rath-Deschner, James Deschner, Susanne Reimann, Andreas Jager, Werner Gotz Tags: Papers Source Type: journals

Cells, growth factors and bioactive surface properties in a mechanobiological model of implant healingEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, we suggested that our innovative theoretical approach was relevant to investigate implant fixation and could potentially help in reduction of implant revision. (Source: Journal of Biomechanics)
Source: Journal of Biomechanics - August 10, 2009 Category: Biomedical Science Authors: G. Guérin, D. Ambard, P Swider Tags: Papers Source Type: journals

Actomyosin contractility spatiotemporally regulates actin network dynamics in migrating cellsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, using a combination of fluorescent speckle microscopy and particle imaging velocimetry techniques, we perturbed the actomyosin system and examined quantitatively the consequence of actomyosin contractility on F-actin network flow and deformation in the lamellipodia of actively migrating fish keratocytes. F-actin flow fields were characterized by retrograde flow at the front and anterograde flow at the back of the lamellipodia, and the two flows merged to form a convergence zone of reduced flow intensity. Interestingly, activating or inhibiting actomyosin contractility altered network flow intensity and conve...
Source: Journal of Biomechanics - August 10, 2009 Category: Biomedical Science Authors: Kennedy Omondi Okeyo, Taiji Adachi, Junko Sunaga, Masaki Hojo Tags: Papers Source Type: journals

An experimental study on the ultimate strength of the adventitia and media of human atherosclerotic carotid arteries in circumferential and axial directionsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study determined the uniaxial tensile strength of human carotid artery sections containing type II and III lesions (AHA classifications). Axial and circumferential oriented adventitia, media and intact specimens (total=73) were prepared from 6 arteries. The ultimate strength in uniaxial tension was taken as the peak stress recorded when the specimen showed the first evidence of failure and the extensibility was taken as the stretch ratio at failure. The mean adventitia strength values calculated using the first Piola–Kirchoff stress were 1996±867 and 1802±703kPa in the axial and circumferential directions respecti...
Source: Journal of Biomechanics - August 10, 2009 Category: Biomedical Science Authors: Zhongzhao Teng, Dalin Tang, Jie Zheng, Pamela K. Woodard, Allen H. Hoffman Tags: Papers Source Type: journals

Quantifying dynamic mechanical properties of human placenta tissue using optimization techniques with specimen-specific finite-element modelsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Motor-vehicle crashes are the leading cause of fetal deaths resulting from maternal trauma in the United States, and placental abruption is the most common cause of these deaths. To minimize this injury, new assessment tools, such as crash-test dummies and computational models of pregnant women, are needed to evaluate vehicle restraint systems with respect to reducing the risk of placental abruption. Developing these models requires accurate material properties for tissues in the pregnant abdomen under dynamic loading conditions that can occur in crashes. A method has been developed for determining dynamic materi...
Source: Journal of Biomechanics - August 10, 2009 Category: Biomedical Science Authors: Jingwen Hu, Kathleen D. Klinich, Carl S. Miller, Giseli Nazmi, Mark D. Pearlman, Lawrence W. Schneider, Jonathan D. Rupp Tags: Papers Source Type: journals

Osteocyte calcium signaling response to bone matrix deformationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we observed the osteocyte calcium signaling response to the quantitatively applied deformation in the bone matrix. A novel experimental system was developed to apply deformation to cultured bone tissue with osteocytes on a microscope stage. As a mechanical stimulus to the osteocytes in bone matrix, in-plane shear deformation was applied using a pair of glass microneedles to bone fragments, obtained from 13-day-old embryonic chick calvariae. Deformation of bone matrix and cells was quantitatively evaluated using an image correlation method by applying for differential interference contrast images of the matri...
Source: Journal of Biomechanics - August 10, 2009 Category: Biomedical Science Authors: Taiji Adachi, Yuki Aonuma, Shin-ichi S.-i. Ito, Mototsugu Tanaka, Masaki Hojo, Teruko Takano-Yamamoto, Hiroshi Kamioka Tags: Papers Source Type: journals

Age effects on the inter-joint coordination during obstacle-crossingEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Seventeen healthy elderly and 17 young adults walked and crossed obstacles of different heights, while sagittal angles (x) and angular velocities (x′) of each joint were measured and their phase angles (ϕ) calculated as tan−1(x′/x). Relative phase angles (RPA) were also obtained, i.e., ϕhip−knee and ϕknee−ankle. The standard deviations of the RPA curve points were averaged to obtain deviation phase (DP) values for the stance and swing phase for each obstacle height. Both groups had similar RPA patterns, for both the leading and the trailing limb. The elderly were found to cross obstacles with increas...
Source: Journal of Biomechanics - August 10, 2009 Category: Biomedical Science Authors: Hsiao-Ching H.-C. Yen, Hao-Ling H.-L. Chen, Ming-Wei M.-W. Liu, Hwa-Chang H.-C. Liu, Tung-Wu T.-W. Lu Tags: Papers Source Type: journals

Contact stress distributions on the femoral head of the emu (Dromaius novaehollandiae)Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study reports in vitro measurement of the contact stress distributions on the emu femoral head during stance phase of the gait cycle, using Fuji pressure-sensitive film. Applied hip loadings were based upon ground reaction forces and hip flexion angles recorded in vivo. The contact stress data showed reasonable homology with the human hip, both in terms of stress magnitude and sites of habitual loading on the femoral head. (Source: Journal of Biomechanics)
Source: Journal of Biomechanics - August 10, 2009 Category: Biomedical Science Authors: Karen L. Troy, Thomas D. Brown, Michael G. Conzemius Tags: Papers Source Type: journals

Mechanical response of periodontal ligament: Effects of specimen geometry, preconditioning cycles and time lapseEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study was conducted as part of research line addressing the mechanical response of periodontal ligament (PDL) to tensile–compressive sinusoidal loading. The aim of the present project was to determine the effect of three potential sources of variability: (1) specimen geometry, (2) tissue preconditioning and (3) tissue structural degradation over time. For the three conditions, selected mechanical parameters were evaluated and compared.(1) Standard flat specimens (obtained by sequentially slicing portions of bone, PDL and dentin using a precision band saw) and new cylindrical specimens (extracted with a diamond-coate...
Source: Journal of Biomechanics - August 9, 2009 Category: Biomedical Science Authors: Marzio Bergomi, H.W. Anselm Wiskott, John Botsis, Tatsuya Shibata, Urs C. Belser Tags: Short Communications Source Type: journals

Optimal inertial sensor location for ambulatory measurement of trunk inclinationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Trunk inclination (TI) is used often to quantify back loading in ergonomic workplace evaluation. The aim of the present study was to determine whether TI can be obtained using a single inertial sensor (IS) on the back, and to determine the optimal IS location on the back for the estimation of TI. Gold standard TI, the angle between the vertical and the line connecting the L5/S1 joint and the trunk centre of mass, was measured using an optoelectronic system. Ten subjects performed experimental trials, each consisting of a symmetric and an asymmetric lifting task, and of a left–right lateral flexion movement. Tri...
Source: Journal of Biomechanics - August 9, 2009 Category: Biomedical Science Authors: Gert S. Faber, Idsart Kingma, Sjoerd M. Bruijn, Jaap H. van Dieën Tags: Short Communications Source Type: journals

Importance of initial stress for abdominal aortic aneurysm wall motion: Dynamic MRI validated finite element analysisEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Currently the transverse diameter is the primary decision criterion to assess rupture risk in patients with an abdominal aortic aneurysm (AAA). To obtain a measure for more patient-specific risk assessment, aneurysm wall stress, calculated using finite element analysis (FEA), has been evaluated in literature. In many cases, initial stress, present in the AAA wall during image acquisition, is not taken into account. In the current study the effect of initial stress incorporation (ISI) is determined by directly comparing wall displacements extracted from FEA and dynamic MRI.Ten patients with an aneurysm diameter we...
Source: Journal of Biomechanics - August 9, 2009 Category: Biomedical Science Authors: M.A.G. Merkx, M. van ’t Veer, L. Speelman, M. Breeuwer, J. Buth, F.N. F.N. van de Vosse Tags: Papers Source Type: journals

Functional calibration procedure for 3D knee joint angle description using inertial sensorsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Measurement of three-dimensional (3D) knee joint angle outside a laboratory is of benefit in clinical examination and therapeutic treatment comparison. Although several motion capture devices exist, there is a need for an ambulatory system that could be used in routine practice. Up-to-date, inertial measurement units (IMUs) have proven to be suitable for unconstrained measurement of knee joint differential orientation. Nevertheless, this differential orientation should be converted into three reliable and clinically interpretable angles. Thus, the aim of this study was to propose a new calibration procedure adapt...
Source: Journal of Biomechanics - August 9, 2009 Category: Biomedical Science Authors: J. Favre, R. Aissaoui, B.M. Jolles, J.A. de Guise, K. Aminian Tags: Papers Source Type: journals

Simulation and study of the behaviour of the transversalis fascia in protecting against the genesis of inguinal herniasEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Simulating the muscular system has many applications in biomechanics, biomedicine and the study of movement in general. We are interested in studying the genesis of a very common pathology: human inguinal hernia. We study the effects that some biomechanical parameters have on the dynamic simulation of the region, and their involvement in the genesis of inguinal hernias. We use the finite element method (FEM) and current models for the muscular contraction to determine the deformed fascia transversalis for the estimation of the maximum strain. We analysed the effect of muscular tissue density, Young's modulus, Poi...
Source: Journal of Biomechanics - August 9, 2009 Category: Biomedical Science Authors: G. Fortuny, J. Rodríguez-Navarro, A. Susín, M. López-Cano Tags: Papers Source Type: journals

Measuring tendon properties in mdx mice: Cell viability and viscoelastic characteristicsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: Muscular dystrophy is a genetic disorder of skeletal muscle characterized by progressive muscle weakness. Here we assessed whether muscle wasting affects cell viability and mechanical properties of extensor digitorum longus (EDL) and of tibialis anterior (TA) tendons from mdx dystrophic mice compared to wild type (WT) mice. mdx mice represent the classical animal model for human Duchenne muscular dystrophy, and show several signs of the pathology, including a decrease in specific force and an increase of fibrotic index. Cell viability of tendons was evaluated by histological analysis, and viscoelastic properties ...
Source: Journal of Biomechanics - August 9, 2009 Category: Biomedical Science Authors: E. Rizzuto, A. Musarò, A. Catizone, Z. Del Prete Tags: Papers Source Type: journals

Dynamics and stability of muscle activations during walking in healthy young and older adultsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract: To facilitate stable walking, humans must generate appropriate motor patterns and effective corrective responses to perturbations. Yet most EMG analyses do not address the continuous nature of muscle activation dynamics over multiple strides. We compared muscle activation dynamics in young and older adults by defining a multivariate state space for muscle activity. Eighteen healthy older and 17 younger adults walked on a treadmill for 2 trials of 5min each at each of 5 controlled speeds (80–120% of preferred). EMG linear envelopes of v. lateralis, b. femoris, gastrocnemius, and t. anterior of the left leg were ...
Source: Journal of Biomechanics - August 9, 2009 Category: Biomedical Science Authors: Hyun Gu Kang, Jonathan B. Dingwell Tags: Papers Source Type: journals