Search Results
Results 151 - 200 of 778
1 2 3 4 5 6 7 8 9 10 >
Soin Sandeep P SP Baltimore, MD, - - 2009
Flexible suture-button devices are used to stabilize the distal tibiofibular joint after syndesmotic rupture, but little is known about how they affect fibular motion during cyclic physiological loading. This study examined how much fibular motion occurs during cyclic loading of ankles repaired with suture-buttons or screws relative to one with ...
Butler David L - - 2009
Bioreactors precondition tissue-engineered constructs (TECs) to improve integrity and hopefully repair. In this paper, we use functional tissue engineering to suggest criteria for preconditioning TECs. Bioreactors should (1) control environment during mechanical stimulation; (2) stimulate multiple constructs with identical or individual waveforms; (3) deliver precise displacements, including those that mimic ...
Arampatzis Adamantios - - 2009
This review examines the effects of short- and long-term static and cyclic mechanical loading on the mechanical properties of tendons. Tendons do not alter their mechanical properties after static and cycling loading that occurs during fatiguing contractions. Adaptations can occur after the application of long-term loading, but the strain magnitude ...
Weishaupt M A - - 2009
REASONS FOR PERFORMING STUDY: The load acting on the limbs and the load distribution between fore- and hindlimbs while performing specific dressage exercises lack objective assessment. HYPOTHESIS: The greater a horse's level of collection, the more load is shifted to the rear and that during the passage the vertical load ...
Crevier-Denoix N - - 2009
REASONS FOR PERFORMING STUDY: Although track surfaces are a risk factor of tendon injuries, their effects on tendon loading at high speed are unknown. Using a noninvasive ultrasonic technique, it is now possible to evaluate the forces in the superficial digital flexor tendon (SDFT) in exercise conditions. OBJECTIVES: To compare ...
Veltink Peter H - - 2009
The power transferred between the human body and the environment at any time and the work performed are important quantities to be estimated when evaluating and optimizing the physical interaction between the human body and the environment in sports, physical labor, and rehabilitation. It is the objective of the current ...
Sevrez Violaine - - 2009
Seven female elite gymnasts performed backward giant circles on the high bar under different conditions of loading. The magnitude (2 or 4 kg) and location (shoulders, waist, and ankles) of load systematically influenced the overall swing duration as well as the relative timing of movements at the joints. An analysis ...
Loram Ian D - - 2009
Human balance is commonly described using linear-time-invariant (LTI) models. The feedback time delay determines the position of balance in the motor-control hierarchy. The extent of LTI control illuminates the automaticity of the control process. Using non-parametric analysis, we measured the feedback delay, extent of LTI control and visuo-motor transfer function ...
Lee Minhyung M Vibration and Acoustics Laboratories, Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, - - 2009
There are many instances where it is desirable to determine, at a distance, whether a subject is carrying a hidden load. Automated detection systems based on gait analysis have been proposed to detect subjects that carry hidden loads. However, very little baseline gait kinematic analysis has been performed to determine ...
Deo Dhanannjay - - 2009
A portable instrumentation rig is presented for characterizing nonlinear viscoelastic anisotropic response of intra-abdominal organ-tissues. Two linearly independent in-situ experiments are performed at each indentation site on the intra-abdominal organ, by subjecting the organ to 1) normal and 2) tangential displacement stimuli using the above robotic device. For normal indentation ...
Knapik Gregory G - - 2009
As the nature of many materials handling tasks have begun to change from lifting to pushing and pulling, it is important that one understands the biomechanical nature of the risk to which the lumbar spine is exposed. Most previous assessments of push-pull tasks have employed models that may not be ...
Watson J - - 2009
We present a comparison of loaded and unloaded carrying kinematics in humans, common chimpanzees (Pan troglodytes), bonobos (Pan paniscus), western lowland gorillas (Gorilla gorilla gorilla) and Bornean and Sumatran orang-utans (Pongo pygmaeus and Pongo abelii). Human hindlimb joint and segment angles were collected during treadmill locomotion using infrared motion analysis ...
Fulcher Geoffrey R - - 2009
Articular cartilage is a viscoelastic material, but its exact behaviour under the full range of physiological loading frequencies is unknown. The objective of this study was to measure the viscoelastic properties of bovine articular cartilage at loading frequencies of up to 92 Hz. Intact tibial plateau cartilage, attached to subchondral ...
Zheng Wenwei - - 2009
Conventional kinesin is a homodimeric motor protein that is capable of walking unidirectionally along a cytoskeletal filament. While previous experiments indicated unyielding unidirectionality against an opposing load up to the so-called stall force, recent experiments also observed limited processive backwalking under superstall loads. This theoretical study seeks to elucidate the ...
Rüggeberg Markus - - 2009
Structure and mechanics of fibre caps of different types of vascular bundles were studied at a certain height in the trunk of the palm Washingtonia robusta. By correlating these features with the distribution of the different bundle types across the trunk, possible strategies to cope with mechanical loads were elucidated. ...
Iwasaki Laura R - - 2009
The likelihood of development of degenerative joint disease (DJD) of the temporomandibular joint (TMJ) is related to the integrity of the TMJ disc. Predilection for mechanical failure of the TMJ disc may reflect inter-individual differences in TMJ loads. Nine females and eight males in each of normal TMJ disc position ...
Rowson Steven - - 2009
The objective of this study was to develop a methodology to measure the tension of the Achilles tendon in cadavers during dorsiflexion. The Achilles tendon was instrumented with a customized load cell designed to measure tension. The leg was inverted and secured in a custom testing apparatus designed to invoke ...
Schmidt Hendrik - - 2008
STUDY DESIGN: Finite element study. OBJECTIVE: To investigate the interaction between the finite helical axis and facet joint loads under combined loading. SUMMARY OF BACKGROUND DATA: Finite helical axes (FHA) in a functional spinal unit can indicate mechanical disorders and are relevant for the development of new arthoplasty techniques. The ...
Hall Rick S - - 2008
Miniature sensors that could measure forces applied by the fingers and hand without interfering with manual dexterity or range of motion would have considerable practical value in ergonomics and rehabilitation. In this study, techniques have been developed to use inexpensive pressure-sensing resistors (FSRs) to accurately measure compression force. The FSRs ...
Lea Simon C - - 2009
BACKGROUND: It is stated that the oscillation patterns of dental ultrasonic scalers are dependent upon whether the instrument is of a magnetostrictive or piezoelectric design. These patterns are then linked to differences in root surface debridement in vitro. MATERIAL AND METHODS: Piezoelectric (A, P) and magnetostrictive (Slimline, TFI-3) ultrasonic scalers ...
Rüggeberg Markus - - 2008
Palms can grow at sites exposed to high winds experiencing large dynamic wind and gust loads. Their stems represent a system of stiff fibrous elements embedded in the soft parenchymatous tissue. The proper design of the interface of the stiffening elements and the parenchyma is crucial for the functioning of ...
Craig Matthew - - 2008
The purpose of this study was to determine the force-time and force-displacement response of the human mandible under direct loading at the chin. Sub-fracture response of the mandible and temporomandibular joint (TMJ) were analyzed from 10 cadavers that were impacted at the chin with a 2.8-kg mass at drop heights ...
Wong Benjamin L BL University of California-San Diego, La Jolla, CA 92093-0412, - - 2008
During joint articulation, the biomechanical behavior of cartilage not only facilitates load-bearing and low-friction, but also provides regulatory cues to chondrocytes. Elucidation of cartilage kinematics under combined compression and shearing conditions clarifies these cues in health and disease. The objectives of this study were to elucidate the effects of lubricant, ...
Faber Gert S - - 2008
This study investigated the effects of ship motion on peak spinal loading during lifting. All measurements were done on a ship at sea. In 1-min trials, which were repeated over a wide range of sailing conditions, subjects lifted an 18 kg box five times. Ship motion, whole body kinematics, ground ...
Frost David M - - 2008
Explosive upper-body movements, with which the load is not thrown (non-ballistic), may comprise a phase during which forces are produced in opposition to the motion of the load. Thirty men completed three test sessions (free weight, ballistic, and pneumatic), each consisting of a one-repetition maximum (1-RM) and four explosive repetitions ...
Mündermann Annegret - - 2008
We examined the relationship between activity, peak load, medial to lateral load distribution, and flexion angle at peak load for activities of daily living. An instrumented knee prosthesis was used to measure knee joint force simultaneously with motion capture during walking, chair sit to stand and stand to sit, stair ...
Meakin Judith R - - 2008
Determining the effect of load carriage on the human spine in vivo is important for determining spinal forces and establishing potential mechanisms of back injury. Previous studies have suggested that the natural curvature of the spine straightens under load, but are based on modelling and external measurements from the surface ...
Boskovski Marko T - - 2008
The new echocardiography-based, load-independent index of diastolic filling (LIIDF) M was assessed using load-/shape-varying E-waves after premature ventricular contractions (PVCs). Twenty-six PVCs in 15 subjects from a preexisting simultaneous echocardiography-catheterization database were selected. Perturbed load-state beats, defined as the first two post-PVC E-waves, and steady-state E-waves, were subjected to conventional ...
McNulty Penelope A - - 2008
Humans can discriminate changes in load viscosity during voluntary contractions. The afferent signal origin is unknown. Microneurographic recordings from 83 single low-threshold afferents were made while participants performed triangular ramps either unloaded or with a viscous load. The neural discharges for each cycle were compared across load and velocity. Fifty-eight ...
Shimokochi Yohei - - 2008
To examine and summarize previous retrospective and observational studies assessing noncontact anterior cruciate ligament (ACL) injury mechanisms and to examine such reported ACL injury mechanisms based on ACL loading patterns due to knee loadings reported in in vivo, in vitro, and computer simulation studies. We searched MEDLINE from 1950 through ...
Varadarajan Kartik M KM Bioengineering Laboratory, Orthopaedic Surgery, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02114, - - 2008
Analysis of polyethylene component wear and implant loosening in total knee arthroplasty (TKA) requires precise knowledge of in vivo articular motion and loading conditions. This study presents a simultaneous in vivo measurement of tibiofemoral articular contact forces and contact kinematics in three TKA patients. These measurements were accomplished via a ...
Zhang Xu - - 2008
Osteoblast, playing a key role in the pathophysiology of osteoporosis, is one of the mechanical stress sensitive cells. The effects of mechanical load-induced changes of mechanical properties in osteoblast cells were studied at real-time. Osteoblasts obtained from young Wistar rats were exposed to mechanical loads in different frequencies and resting ...
Vilchinska Nora A - - 2008
Dynamic loaded large object is under research. Long time periods (8 years) measurements are made by variety loads: from quasi static till strong motion. Short time measurements start from quasi static and load goes step-by-step till strong motion- maximum loaded- and return in the same way to quasi static. This ...
Iliopoulos Dimitrios C - - 2009
This study aimed to assess regional and directional differences in the mechanical properties of ascending thoracic aortic aneurysms (ATAA). Whole fresh ATAA were taken from twelve patients, undergoing elective surgical repair, and cut into tissue specimens. These were divided into groups according to direction and region, and subjected to uniaxial ...
Chen Jiann-Jong - - 2008
A hysteresis-current-controlled (HCC) buck converter with active current-sensing and phase-frequencylocked techniques is presented in this paper. The proposed active current-sensing technique can not only consume less power than previous techniques, but also fully sense the inductor current. Although the buck converter is HCC, the switching frequency can be constant due ...
Challis John H - - 2008
Soft tissue motion occurs as impulsive loads that are applied to the skeletal system. It has been demonstrated that the wavelike motion of these wobbling masses can reduce the loads acting on the musculoskeletal system. This is an important concept to consider, whether the loads acting on the musculoskeletal system ...
Virani Nazeem A - - 2008
We developed biomechanical and finite element models, using high-strength polyurethane foam blocks, to represent the glenoid bone/baseplate junction to determine if increasing the distance between the glenoid bone and the center of rotation of the glenosphere increases baseplate motion during static loading in the reverse shoulder design. Although there was ...
Elsheikh Ahmed - - 2008
The suitability of porcine corneas as approximate models for human corneas in mechanical property characterisation studies is experimentally assessed. Thirty seven human donor corneas and thirty four ex-vivo porcine corneas were tested under inflation conditions to determine their short-term stress-strain behaviour and long-term creep behaviour up to 2.8 h (10,000 ...
Bader Rebecca A - - 2008
Hydrogels have been proposed as candidates for tissue replacement; however, current systems are often highly susceptible to hydrolytic degradation and have not been shown to mimic the viscoelastic behavior of the native tissue when subjected to dynamic loading conditions. In the present work, 1,2-epoxy-5-hexene modified poly(vinyl alcohol) was crosslinked via ...
Wang Wei-Chih - - 2008
A flexible high-resolution sensor capable of measuring the distribution of pressure beneath the foot via a microfabricated optical waveguide system is presented. The uniqueness of the system is in its batch fabrication process, which involves a microfabrication molding technique with polydimethylsiloxane (PDMS) as the optical medium. The sensor manufacturing technique ...
Singh M - - 2008
Mandibular condylar cartilage plays a crucial role in temporomandibular joint (TMJ) function, which includes facilitating articulation with the temporomandibular joint disc and reducing loads on the underlying bone. The cartilage experiences considerable tensile forces due to direct compression and shear. However, only scarce information is available about its tensile properties. ...
Biss Matthew M - - 2008
An adjustable Wollaston-like prism is characterized for use in shearing- and differential schlieren-interferometry with laser and white-light illumination. We demonstrate that a polycarbonate prism under mechanical loading behaves identically to Wollaston's classical birefringent beam splitter. A linear relationship is found between the pure bending moment applied to the polycarbonate prism ...
Park Seonghun S School of Mechanical Engineering, Pusan National University, Busan, Republic of Korea, South Korea. - - 2008
The objective of this study was to test the hypothesis that enzymatic degradation by collagenase significantly reduces dynamic moduli and increases compressive strains of bovine articular cartilage under physiological compressive stress levels and loading frequencies. Twenty-seven distal femoral cartilage plugs (3 mm diameter) were loaded in a custom apparatus under ...
Chew John Z Z - - 2008
In our movements and posture, we always act against a physical load. A key property of any load is its elastic stiffness (K), which describes how the force required to hold it must change with position. Here we examine how load stiffness affects the ability to maintain a stable posture ...
Seven Yasin B - - 2008
The goal of the present study was to determine the thus far unstudied effects of back loading on the kinematics and kinetics of sit-to-stand (STS) motion in healthy children. Fifteen children (8 boys, 7 girls, mean age 9.6 years, SD 1.2 years) were tested with no back load and with ...
Lundström T - - 2008
Thirteen Norway spruce [Picea abies (L.) Karst.] trees of different size, age, and social status, and grown under varying conditions, were investigated to see how they react to complex natural static loading under summer and winter conditions, and how they have adapted their growth to such combinations of load and ...
Willardson Jeffrey M - - 2008
The purpose of this study was to compare squat strength gains and volume components when resting 2 minutes vs. 4 minutes between sets over multiple mesocycles. After the first squat 1 repetition maximum, 15 trained men were matched and randomly assigned to either a 2-minute (n = 7) or a ...
Sharpe S R - - 2008
This study examined the transverse plane kinematics of the pelvis, thorax and head while participants walked at a range of speeds on a treadmill under three load conditions: no load, with a loaded backpack with no hip belt and with a loaded backpack with a hip belt. Research has suggested ...
Herring Susan W SW University of Washington, Seattle, Wash., USA. - - 2008
In addition to their role in skull growth, sutures are sites of flexibility between the more rigid bones. Depending on the suture, predominant loading during life may be either tensile or compressive. Loads are transmitted across sutures via collagenous fibers and a fluid-rich extracellular matrix and can be quasi-static (growth ...
Chen Xu-Yi - - 2008
BACKGROUND: Mechanical stimuli affected bone adaptation, however, the mechanism on a dose-response relationship between mechanical stimuli and bone response is unclear. Therefore, we established a mechanobiology model to evaluated the adaptive response of bone to strain deformation at high-frequencies (5-15 Hz) of externally applied strain. METHODS: The ulnae of adult ...
1 2 3 4 5 6 7 8 9 10 >