Search Results
Results 301 - 350 of 778
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Mason David R - - 2005
OBJECTIVE: To determine the distribution of force between the articular surfaces of the humerus and radius and between the humerus and ulna in normal canine forelimbs. SAMPLE POPULATION: 12 cadaveric canine right forelimbs. PROCEDURE: Transarticular force maps were created by placing a tactile array pressure sensor into the elbow joint ...
Koolstra J H - - 2005
The jaw joint plays a crucial role in human mastication. It acts as a guidance for jaw movements and as a fulcrum for force generation. The joint is subjected to loading which causes tensions and deformations in its cartilaginous structures. These are assumed to be a major determinant for development, ...
Donzelli Peter S - - 2004
Understanding the biomechanical nature of the degeneration of the temporomandibular joint requires a coupling between experimental measurements and numerical simulation. In this study, geometry measured from MRI, and motion obtained from a specially designed optoelectronic system are fed into a three-dimensional biphasic finite element analysis to generate the spatial and ...
Shultz Sandra J - - 2005
We examined whether neuromuscular reflexes were altered with anterior loads applied to the tibio-femoral joint. A ligament testing device was modified by attaching a reflex hammer to a steel mounted frame to illicit a patellar tendon tap, while anterior directed loads displaced the tibia on the femur. Five trials were ...
Kingma Idsart - - 2004
This study investigated the effects of initial load height and foot placement instruction in four lifting techniques: free, stoop (bending the back), squat (bending the knees) and a modified squat technique (bending the knees and rotating them outward). A 2D dynamic linked segment model was combined with an EMG assisted ...
Arangio George A - - 2004
OBJECTIVE: The hypothesis tested was that the increased load on the medial arch in the adult flat foot can be reduced through a 6 mm subtalar arthroereisis. DESIGN: A three-dimensional multisegment biomechanical model was used in conjunction with experimental data and data from the literature. BACKGROUND: Biomechanical models have been ...
McKinley Todd O - - 2004
The etiology of posttraumatic arthritis is poorly understood. One possible mechanism involves a mechanical insult to the cartilage matrix that affects chondrocyte function. To better understand the etiology of posttraumatic arthritis, pathomechanic changes in articular contact mechanics resulting from injury during physiologic motion and loading need to be determined. Previous ...
Granata K P - - 2004
Effective stiffness of the musculoskeletal system was examined as a function of the characteristics of an external load. Thirteen healthy subjects provided active contraction of the ankle plantarflexion musculature in a neutral ankle posture to support an external load. Musculoskeletal stiffness was computed from kinetic data recorded in response to ...
Riek S - - 2004
This experiment investigated whether the stability of rhythmic unimanual movements is primarily a function of perceptual/spatial orientation or neuro-mechanical in nature. Eight participants performed rhythmic flexion and extension movements of the left wrist for 30s at a frequency of 2.25 Hz paced by an auditory metronome. Each participant performed 8 ...
Lee K K - - 2004
OBJECTIVE: A three-dimensional poroelastic finite element (FE) L2-L3 model was developed to study lumbar spinal instability and intrinsic parameters in the intervertebral disc (IVD). METHODS: The FE model took into consideration poroelasticity of the IVD and viscoelasticity of the annulus fibers and ligaments to predict the time-dependent behavior. To simulate ...
Jia Xiaohong - - 2004
The effects of inertial loads on the interface stresses between trans-tibial residual limb and prosthetic socket were investigated. The motion of the limb and prosthesis was monitored using a Vicon motion analysis system and the ground reaction force was measured by a force platform. Equivalent loads at the knee joint ...
Larter S C - - 2004
Abstract This study investigated whether there is a relationship between reading age and clinical optometric tests that have varying degrees of spatial loading in their design. Spatial loading in this context is the demand on the visual system to process information about the relative position and orientation of stimuli. A ...
Wimmer Markus A - - 2004
This study has been based on the assumption that articular motion is an important aspect of mechanotransduction in synovial joints. For this reason a new bioreactor concept, able to reproduce joint kinematics more closely, has been designed. The prototype consists of a rotating scaffold and/or cartilage pin, which is pressed ...
Barth Friedrich G - - 2004
Spiders have highly developed mechanosensory systems, some of which provide access to forms of stimulation alien to our own sensations. Studies of hair-shaped air movement detectors (trichobothria) and tactile sensors have uncovered an outstanding refinement of the processes of stimulus uptake and stimulus transformation, which reflect details of both stimulus ...
Darainy Mohammad - - 2004
We used a robotic device to test the idea that impedance control involves a process of learning or adaptation that is acquired over time and permits the voluntary control of the pattern of stiffness at the hand. The tests were conducted in statics. Subjects were trained over the course of ...
van der Burg J C E - - 2004
Low back injury is associated with sudden movements and loading. Trunk motion after sudden loading depends on the stability of the spine prior to loading and on the trunk muscle activity in response to the loading. Both factors are not axis-symmetric. Therefore, it was hypothesized that the effects on trunk ...
Zill Sasha - - 2004
This article reviews recent findings on how forces are detected by sense organs of insect legs and how this information is integrated in control of posture and walking. These experiments have focused upon campaniform sensilla, receptors that detect forces as strains in the exoskeleton, and include studies of sensory discharges ...
Pataky Todd - - 2004
The goal of the study was to examine the force sharing among the fingers during static prehension under systematic loading and postural changes. A custom-built handle was constructed that allowed for bi-directional loading (upward and downward) with different load magnitudes (250, 750 and 1250 g). Five- and three-digit grasps were ...
McKinley Todd O - - 2004
The etiology of posttraumatic arthritis is understood poorly but it clearly has a pathomechanical component. Posttraumatic arthritis likely results from irreversible cartilage damage sustained at the time of injury and chronic cartilage overloading resulting from articular incongruity and instability. However, the relative importance of instability and incongruity is unknown. Clinical ...
Cronin J - - 2004
The purpose of this study was to determine if three training loads equated by volume differed in terms of the temporal, kinematic and kinetic characteristics of each set. Twelve experienced weightlifters (30.2+/-10.6 years old and 75.8+/-13.0 kg) performed three sets (6 x 30% 1RM, 3 x 60% 1RM and 2 ...
Conditt Michael A - - 2004
BACKGROUND: The capture mechanisms of modular tibial total knee components may allow relative micromotion between the insert and the base-plate, leading to wear at the nonarticulating (backside) surface. Although retrieved components often display laxity in the capture mechanism in the unloaded condition, the magnitude of the relative motion that actually ...
Twiste M - - 2004
An electromechanical system is described that comprises a cam and two linear displacement transducers for measuring two-degree of freedom. This is aimed at quantifying the extent and pattern of both transverse rotation and longitudinal translation that takes place during amputee gait at what is sometimes termed a "torque-shock absorbing adapter" ...
Hinken Aaron C - - 2004
Force generation in striated muscle is coupled with inorganic phosphate (P(i)) release from myosin, because force falls with increasing P(i) concentration ([P(i)]). However, it is unclear which steps in the cross-bridge cycle limit loaded shortening and power output. We examined the role of P(i) in determining force, unloaded and loaded ...
Mukou Masao - - 2004
The anterior byssal retractor muscle (ABRM) of the bivalve Mytilus edulis shows a prolonged tonic contraction, called the catch state. To investigate the catch mechanism, details of which still remain obscure, we studied the mechanical responses of ABRM fibres to quick increases in load applied during maximum active isometric force ...
White Scott C - - 2004
Unequal leg lengths result in asymmetric limb loading but opinions vary on the size of the difference inducing abnormal loading, and which limb sustains the greater load. Our study compared limb-loading asymmetries during walking for subjects with anatomic leg-length discrepancies between 1.0 and 3 cm, subjects without length discrepancies, and ...
Chen Y - - 2004
Some observations on the milling of alpha-lactose monohydrate with a Retsch single-ball mill are reported. The effects of mill loading and frequency of the mill motion were investigated. At a given frequency, a lower mill loading showed a higher milling efficiency. For a given mill loading, size reduction rate increased ...
Nieminen Heikki J - - 2004
High-frequency ultrasound (US) measurements may provide means for the quantification of articular cartilage quality. Bovine patellar cartilage samples (n = 32) at various degenerative stages were studied using US attenuation measurements in the 5- to 9-MHz frequency range. The results were compared with the histologic, biochemical and mechanical parameters obtained ...
Almeras Tancrede - - 2004
BACKGROUND AND AIMS: Stem shape in angiosperms depends on several growth traits such as elongation direction, amount and position of axillary loads, stem dimensions, wood elasticity, radial growth dynamics and active re-orientation due to tension wood. This paper analyses the relationship between these biomechanical factors and stem shape variability. METHODS: ...
Gueguen N N Laboratoire Mouvement et Perception, Faculté des Sciences du Sport, CNRS-Université de la Méditerranée, 163 avenue de Luminy, 13288 Marseille cedex 9, France. - - 2004
During lateral leg raising, a synergistic inclination of the supporting leg and trunk in the opposite direction to the leg movement is performed in order to preserve equilibrium. As first hypothesized by Pagano and Turvey (J Exp Psychol Hum Percept Perform, 1995, 21:1070-1087), the perception of limb orientation could be ...
Warden S J - - 2004
A dose-response relationship has been shown between loading frequency and cortical bone adaptation for frequencies of up to 10 Hz, and is presumed to persist with further increases in frequency. Studies herein aimed to investigate cortical bone adaptation to loading frequencies of 1, 5, 10, 20 and 30 Hz. Two ...
Lieberman Daniel E - - 2004
Long bone loading histories are commonly evaluated using a beam model by calculating cross-sectional second moments of areas (SMAs). Without in vivo strain data, SMA analyses commonly make two explicit or implicit assumptions. First, while it has long been known that axial compression superimposed on bending shifts neutral axes away ...
Noah J A - - 2004
Sense organs in the legs that detect body weight are an important component in the regulation of posture and locomotion. We tested the abilities of tibial campaniform sensilla, receptors that can monitor forces in the cockroach leg, to encode variations in body load in freely standing animals. Small magnets were ...
Hoozemans Marco J M - - 2004
The objective of this study was to quantify the mechanical load on the low back and shoulders during pushing and pulling in combination with three task constraints: the use of one or two hands, three cart weights, and two handle heights. The second objective was to explore the relation between ...
LaMothe Jeremy M - - 2004
Mechanical loading can significantly affect skeletal adaptation. High-frequency loading can be a potent osteogenic stimulus. Additionally, insertion of rest periods between consecutive loading bouts can be a potent osteogenic stimulus. Thus we investigated whether the insertion of rest-periods between short-term high-frequency loading bouts would augment adaptation in the mature murine ...
Sandler E A - - 2004
REASONS FOR PERFORMING STUDY: Previous in vitro pilot studies have defined a potentially beneficial effect of insulin-like growth factor-1 (IGF-1) and triamcinolone acetonide (TA) on interleukin-1 (IL-1)-conditioned equine cartilage. Furthermore, an optimal dose for IGF-1 treatment alone has been documented previously using the same test system as in the current ...
Watanabe N N Department of Artificial Organs, Tokyo Medical & Dental University, - - 2004
Red blood cells (RBCs) in the cardiovascular devices are exposed to varying degree of the shear stress from all the directions. However the RBCs' deformability or the deformation capability under such a shear stress is not well understood. In this study, we designed and built a system that can induce ...
Abbott Judith A - - 2004
Academically, quantitative measurement of texture is essential for the study of the chemical and physiological mechanisms of texture. Commercially, quantitative measurement of texture is essential to ensure the quality of produce at packout. The diversity of tissues involved, the variety of attributes required to fully describe textural properties, and the ...
Oosterom R - - 2004
Results of shoulder replacements are inferior and must be improved. Two of the major problems of total shoulder replacements are loosening of cemented glenoid components and wear of polyethylene inlays of uncemented, metal-backed glenoid components. The aim of this study is to investigate the influence of joint conformity on glenoid-component ...
Meyer D C - - 2004
Tendon tension in vivo may be determined indirectly by measuring intratendinous pressure, by using a buckle transducer or by measuring the tendon strain. All of these methods require appropriate calibration, which is highly dependent on various variables. To measure the tendon load in vivo during a period of 2 weeks ...
Takeuchi Shoji - - 2004
A radio frequency (RF) telemetry system with a shape memory alloy microelectrode was designed and fabricated. The total size and weight are 15 mm x 8 mm and 0.1 g, respectively. Since the telemeter is small and light enough to be loaded on a small animal such as an insect, ...
Turner H C - - 2004
The aim of this study was to develop a basic measurement system to estimate the vertical loading of the upper limb during the sit-to-stand activity, with a view to increasing the understanding of the loading of the wrist in daily living activities. A chair was adapted and instrumented with strain ...
Park S S Columbia University, Department of Mechanical Engineering, New York, NY 10027, - - 2004
The objective of this study was to characterize the dynamic modulus and compressive strain magnitudes of bovine articular cartilage at physiological compressive stress levels and loading frequencies. Twelve distal femoral cartilage plugs (3mm in diameter) were loaded in a custom apparatus under load control, with a load amplitude up to ...
Gabriel Mary T - - 2004
The anterior cruciate ligament (ACL) can be anatomically divided into anteromedial (AM) and posterolateral (PL) bundles. Current ACL reconstruction techniques focus primarily on reproducing the AM bundle, but are insufficient in response to rotatory loads. The objective of this study was to determine the distribution of in situ force between ...
Bleetman A - - 2003
BACKGROUND: Stab attacks generate high loads, and to defeat them, armour needs to be of a certain thickness and stiffness. Slash attacks produce much lower loads and armour designed to defeat them can be far lighter and more flexible. METHODS AND SUBJECTS: Phase 1: Human performance in slash attacks: 87 ...
Ochia Ruth S - - 2003
Previous studies have implied that increases in loading rate resulted in changes in vertebral mechanical properties and these changes were causative factors in the different fracture types seen with high-speed events. Thus many researchers have explored the vertebral body response under various loading rate conditions. No other study has investigated ...
Kent Richard - - 2003
Thoracic deformation under an applied load is an established indicator of injury risk, but the force required to achieve an injurious level of deformation currently is not understood adequately. This article evaluates how two potentially important factors, loading condition and muscle tensing, affect the structural response of the dynamically loaded ...
Izambert O - - 2003
The aim of this study was to analyse the dynamic response of the human intervertebral disc to vibration in a physiologically relevant frequency spectrum. Eight lumbar intervertebral discs were harvested. After preparation, each sample was subjected to a pre-loading and then dynamic compression (from 5 to 30 Hz). The dynamic ...
Ohki Yukari - - 2004
We examined the effects of repetitive experience of feedback events and cue signals on adaptation of bimanual reactive response, both of which can be used to predict load forces on handheld objects. Normal human subjects used bimanual index fingers to hold two plates mounted on separate torque motors. Sensory-driven reactive ...
Wolf Amela - - 2003
Chondrocytes within articular cartilage experience complete unloading between loading cycles and in so doing utilize mechanical signals to regulate their own metabolic activities. A strongly elevated fibronectin content is an early feature in osteoarthritis and appears to be related to increases in both the synthesis and retention of this glycoprotein. ...
Irschick Duncan J - - 2003
Stride length, stride frequency and power output are all factors influencing locomotor performance. Here, we first test whether mass-specific power output limits climbing performance in two species of geckos (Hemidactylus garnoti and Gekko gecko) by adding external loads to their bodies. We then test whether body size has a negative ...
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