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Weeks D L - - 1996
1. We analyzed the rapid adaptation of elbow movement to unexpected changes in external load conditions at the elbow joint. The experimental approach was based on the lambda model, which defines control variables (CVs) setting the positional frames of reference for recruitment of flexor and extensor motoneurons. CVs may be ...
Bennis N - - 1996
A bimanual loading task was studied in eight right-handed normal subjects and nine hemiparetic patients in order to detect anticipatory adjustments and to analyse the reflex and voluntary, responses induced by the perturbation. The left forearm (or the impaired side in patients) was flexed at approximately 90 degrees and free ...
Steffen H - - 1996
In patients with obligate fixation disparity central objects may be seen double when peripheral fusion manifests. The diplopia cannot be treated with prisms because fusional power of the peripheral retina breaks down central fusion. A different cortical integration of the peripheral and central retina is supposed to be the underlying ...
Collett TS - - 1996
A major reason for analysing short-range navigation is that it is relatively easy to record on video tape the details of an animal's behaviour over an area of about a square metre. Frequently, the orientation of the animal's body is revealed in addition to its trajectory through space. This is ...
Komi P V - - 1996
Direct in vivo tendon force measurements open up new possibilities for understanding of muscle-tendon loads during natural locomotion. The present report presents a new optic fibre method for such applications. The method is based on light intensity modulation by mechanical modification of the geometric properties of the optic fibre. A ...
Linossier M T - - 1996
A group of 15 untrained male subjects pedalled on a friction-loaded cycle ergometer as fast as possible for 5-7 s to reach the maximal velocity (vmax) against different braking forces (FB). Power was averaged during a complete crank rotation by adding the power dissipated against FB to the power necessary ...
Pattin C A - - 1996
Fatigue damage accumulation has been demonstrated in living bone and postulated as a stimulus to the bone modeling and remodeling response. Mechanical property degradation is one manifestation of fatigue damage accumulation. This study examines changes in secant modulus and cyclic energy dissipation behavior during axial load-controlled fatigue loading of cortical ...
Lindbeck L - - 1995
The load on the lower back was calculated by means of biomechanical models of different degrees of complexity for twelve subjects lifting 30-kg sacks from three different heights. Motions and ground force reactions were registered by means of a video camera, an advanced optoelectronic measuring system, and a force plate. ...
Hannafin J A - - 1995
The effect of stress deprivation and cyclic tensile loading on the mechanical and histologic properties of the canine flexor digitorum profundus tendon was examined using an in vitro system. Stress deprivation resulted in a progressive and statistically significant decrease in the tensile modulus over an 8-week period. Histologically, stress-deprived tendons ...
Markolf K L - - 1995
Injuries to the anterior cruciate ligament frequently occur under combined mechanisms of knee loading. This in vitro study was designed to measure levels of ligament force under dual combinations of individual loading states and to determine which combinations generated high force. Resultant force was recorded as the knee was extended ...
Bach J M - - 1995
This paper describes the design and accuracy evaluation of a new six degree of freedom load application system for in vitro testing of the human knee joint. External loads of both polarity in all six degrees of freedom can be applied either individually or in any combination while the knee ...
Hollis J M - - 1995
A joint testing system was designed to transmit a specified motion or force to a joint in all six degrees of freedom (d.o.f.) using a spatial linkage system for position feedback. The precise reproducibility of position provided by this method of position feedback allows determination of in situ ligament forces ...
Lafortune M A - - 1995
The understanding of impact mechanics during locomotion is important for research within the fields of injury prevention and footwear design. Instrumented missiles offer a worthy solution to the lack of control inherent in in vivo activities and to the isolated nature of tissue studies. However, missiles cannot mimic the magnitude ...
Luo G - - 1995
Strain rate is implemented as a stimulus for surface bone remodeling. Using idealized models for trabecular bone structures, the surface remodeling predictions using the strain rate as the stimulus are compared with the predictions using the peak strain magnitude as the stimulus. For a uniaxially loaded cruciform shape, the comparison ...
GradoĊ„ L - - 1995
The role of alveolar macrophages in the process of the human lung clearance is summarised. Three patterns of alveolar macrophage (AM) displacement on the surface of alveolus are distinguished depending on the loading of the surface with insoluble deposits, i.e. directional, directional with small stochastic noise and purely random. The ...
Daubenspeck J A - - 1995
We applied external flow resistive (R) and elastic (E) mechanical loads over the entire respiratory cycle to five normal subjects by using a pseudorandom loading protocol. Loads ranged in magnitude from imperceptible (R0/E0) through just perceptible (R1/E1) to large (R2/E2) and resulted in respiratory pattern responses that were due to ...
Gagnon M - - 1995
Some epidemiological data have suggested that many physical causes of low back pain such as bending and twisting were, in fact, sudden maximal efforts incidentally carried out at the moment of accident. Sudden loading conditions may be encountered in several circumstances, one of them being the recuperation of a falling ...
Yoganandan N - - 1995
The human spine is a complex, heterogeneous nonlinear and viscoelastic structure. In addition, in vivo loading is not uniaxial. Although many studies on the mechanical behavior of the spine under "pure" forces and single cycle load applications exist, little research is conducted with complex cyclic loads. In this study, we ...
Callaghan J P - - 1995
STUDY DESIGN: This study analyzed anatomic and neural control characteristics of the trunk musculature. Subjects were exposed to external shear and compressive loads with equivalent moments to evaluate activation patterns and loading on the low back. OBJECTIVES: The migration of activity between the thoracic and lumbar erector spinae muscle groups ...
Zdravkovic V - - 1995
The rotational stability of the proximal carpal row was tested on six unembalmed human cadaver hand specimens. The physiological load conditions were stimulated by loading the wrist flexor and extensor tendons. Pure torque was introduced to the lunate, scaphoid and triquetrum, one at a time, by means of a dynamometer ...
Plamondon A - - 1995
The purpose of this study was to examine the reaction moments at L(5)/S(1) about the three orthogonal orthopaedic axes on the trunk when performing asymmetrical lifting tasks under six experimental conditions. The first three conditions were three lifting modes referring to different load trajectories (diagonal, extension then twisting, twisting then ...
Tijhuis L - - 1995
The dynamic change in the overall detachment rate of spherical biofilms in a biofilm airlift suspension reactor was measured after a downshift of the substrate loading rate to zero while all other conditions remained constant. In contrast to the expectations, the overall detachment rate decreased rapidly to a nearly stable ...
Draganich L F - - 1995
We investigated the changes in distance between Gerdy's tubercle on the tibia and points on the posterior two thirds of the lateral surface of the lateral femoral condyle and adjacent lateral femoral shaft in 15 cadaveric knees. A three-dimensional digitizer was used to quantify motion of the knee during flexion ...
Wang X T - - 1995
Wallaby tail tendons fail after repeated application of stresses much lower than would be needed to break them in a single pull. We show that this a fatigue phenomenon, distinct from the creep rupture that occurs after prolonged application of a constant stress. The two phenomena are disctinguished by experiments ...
Scholz J P - - 1995
BACKGROUND AND PURPOSE: This article reports individual differences in the coordination (ie, the relative timing of joint movements and muscle activity) of squat lifting identified by extended analysis of data reported in the authors' companion article in this issue. SUBJECTS: Two post hoc groups of 6 subjects each were identified ...
Scholz J P - - 1995
BACKGROUND AND PURPOSE: In this study, we examined changes in kinematic and electromyographic (EMG) measurements of the coordination (ie, the relative timing of joint movements and muscle activity) of a squat-lifting task in response to lifting increasing loads. SUBJECTS: Fifteen male industrial workers served as a sample of convenience. METHODS: ...
Chad K E - - 1995
The present study was designed to determine the differences in thermoregulatory responses and the levels of muscle fatigue in the seated worker, performing a task involving a light metabolic load (typing), versus the standing worker, undertaking a task of a heavier metabolic load (lifting), in different climatic conditions (neutral and ...
Luczak A - - 1995
This study was a joint physiological and psychological experiment undertaken in order to determine changes in physiological and psychological human functions under the combined influence of heat, noise and physical activity. Seven experimental situations were simulated in a climatic chamber, with different configurations of three independent variables: heat (40 degrees ...
Buckwalter J A - - 1995
One of the most important advances in the treatment of musculoskeletal injuries has come from understanding that controlled early resumption of activity can promote restoration of function, and that treatment of injuries with prolonged rest may delay recovery and adversely affect normal tissues. In the last decade of the nineteenth ...
Kristjuhan Û - - 1995
The aim of this study was to characterize changes in the limb perimeters of workers in various widespread occupations in Estonian industry. Investigations were carried out using special measuring instruments designed in Tallinn Technical University. The subjects under investigation consisted of 202 workers: garment workers, tailoring cutters, shoe factory operators, ...
Khoo B C - - 1995
A dynamic biomechanical model to determine loads (joint forces) attained at the lumbosacral joint-centre during the stance phase of normal level walking was developed. The biomechanical model was based on rigid free body-segments; namely, the foot, shank, thigh, pelvis and head, arms and trunk (HAT) segments. In this biomechanical model, ...
Hult E - - 1995
The goal of this study was to measure the in vivo viscoelastic response of spinal motion segments loaded in compression using a porcine model. Nine pigs were used in the study. The animals were anaesthetized and, using surgical techniques, four intrapedicular screws were inserted into the vertebrae of the L2-L3 ...
Walker P S - - 1995
The purpose of the study was to estimate the anterior-posterior displacements that would occur with total knee prosthetic designs of different sagittal radii under functional conditions. A key question was whether some designs provided excessive constraint. Patients who had different total knee prosthetic designs were tested in a special rig ...
Lau D - - 1994
In specifications of high performance human centrifuges, different definitions of the term "G-load onset rate" occur. This paper compares four of these definitions and discusses the motivation and its advantages and disadvantages from the technical point of view. The four definitions are applied to a high performance human centrifuge to ...
Kumar S - - 1994
Ten normal young male and ten normal young female subjects (each group with a mean age of 21.1 years) performed isometric and isokinetic (50 cm per second) push and pull activity at 35 cm, 100 cm and 150 cm heights. The subjects were placed on a specially designed subject-stabilizing-platform to ...
Kumar S - - 1994
Nine normal male subjects (mean age 28.2 years and mean weight 72.6 kg) performed 20 standardized maximal effort lifting tasks. They were asked to perform stoop and squat lifts at half, three-quarters and full individual horizontal reach distances in mid-sagittal plane in isometric and isokinetic modes (fixed velocity 60 cm/s). ...
Hagen K B - - 1994
STUDY DESIGN: Local thigh and low back perceived exertion (RPE), sagittal peak load moments, and leg and trunk muscular activity during repetitive submaximal lifting, with squat and stoop technique, were investigated. OBJECTIVES: This study analyzed changes in kinetic variables caused by changes in body movements during the lifting bouts, and ...
Goel V K - - 1994
A nonlinear, three-dimensional finite element model of the ligamentous L4-S1 segment was developed to analyze the dynamic response of the spine in the absence of damping. The effects of the upper body mass were simulated by including a mass of 40 kg on the L4 vertebral body. The modal analyses ...
McGill S M - - 1994
STUDY DESIGN AND METHODS: This study used an anatomically detailed model of the lumbar tissues, driven from biologic signals of vertebral displacement and myoelectric signals, to estimate individual muscle and passive tissue force-time histories during the performance of the "flexion-relaxation" maneuver. Eight male university students performed three trials each of ...
Bloch-Salisbury E - - 1994
Resistive and elastic loads added to inspiration are readily detected, and detection latencies vary as a function of load magnitude and load type. In the present study, we recorded endogenous event-related potentials (i.e., N2 and P3) to the detection and classification of large (15.0 cmH2O.1-1.s and 70.0 cmH2O/l) and small ...
Hjertén G - - 1994
The initial forelimb loading of a horse trotting at 3.7 ms-1 on a treadmill was studied by use of an instrumented shoe, accelerometers and high-speed cinematography. At the beginning of the stance phase the forelimb was loaded successively from the hoof. This is suggested to be an important factor for ...
Flynn G - - 1994
With a view towards the design of a system incorporating both the use of chemotherapeutics and photodynamic therapy for use in cancer treatment modalities, erythrocytes have been loaded with methotrexate and subsequently photosensitized by exposure to hematoporphyrin derivative. Loading of methotrexate into erythrocytes has been optimized by examining variations in ...
Arokoski J - - 1994
The effects of long distance running training (up to 40km/day) on the biomechanical properties of young canine articular cartilage were investigated using in situ indentation creep technique. The stiffness of articular cartilage was determined in the form of instantaneous and equilibrium shear moduli. The rate of cartilage deformation was also ...
Andriacchi T P - - 1994
The dynamics of malalignment are based on the combination of the static limb alignment and the dynamics of loading at the knee during walking and other activities of daily living. Dynamic loading at the knee can be influenced by subconscious control of limb position such as foot placement, active muscle ...
Kim Y J - - 1994
The biosynthetic response of calf cartilage disk explants to small-amplitude dynamic compression was studied in radially unconfined compression over a wide range of frequencies. The relative importance of oscillatory fluid flow, hydrostatic pressure, streaming potential, and cell deformation in modulating chondrocyte metabolism was explored by quantifying the frequency dependence and ...
Zeng Y - - 1994
A theoretical model is developed to predict the fluid shear stress and streaming potential at the surface of osteocytic processes in the lacunar-canalicular porosity of an osteon when the osteon is subject to mechanical loads that are parallel or perpendicular to its axis. The theory developed in Weinbaum et al. ...
Hannafin J A - - 1994
This study was designed to determine the effects of various loading conditions (no load and static and cyclic tensile load) on the water content and pattern of nutrient diffusion of canine flexor tendons in vitro. Region D (designated by Okuda et al.) of the flexor digitorum profundus was subjected to ...
Lumley P J - - 1994
The aim of this study was to develop a model system to demonstrate the pattern of load and how much is applied. A lower molar was mounted on a beam and attached to a mandibular phantom head jaw. A strain gauge fitted to the beam allowed loading of the molar ...
Cowin S C - - 1994
In this technical note a sufficiency condition is established for the stability of a strain-energy-based bone remodeling theory in the special case of a beam loaded by an axial force and a bending moment. In a previous report the same condition was shown to be a necessary condition for stability ...
Törner M - - 1994
Ship motions are recognized by fishermen as a cause of high musculo-skeletal load. In the present study, the motions of a Swedish trawler at sea were registered over three degrees of freedom. Simultaneously, the working postures of a fisherman on board were registered in the sagittal plane during five different ...
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