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Human Movement (human + movement)
Selected AbstractsMetabolic cost of lengthening, isometric and shortening contractions in maximally stimulated rat skeletal muscleACTA PHYSIOLOGICA, Issue 2 2004J. G. M. Beltman Abstract Aim:, The present study investigated the energy cost of lengthening, isometric and shortening contractions in rat muscle (n = 19). Methods:, With electrical stimulation the rat medial gastrocnemius muscle was maximally stimulated to perform 10 lengthening, isometric and shortening contractions (velocity 25 mm s,1) under experimental conditions (e.g. temperature, movement velocity) that resemble conditions in human movement. Results:, Mean ± SD force,time-integral of the first contraction was significantly different between the three protocols, 2.4 ± 0.2, 1.7 ± 0.2 and 1.0 ± 0.2 N s, respectively (P < 0.05). High-energy phosphate consumption was not significantly different between the three modes of exercise but a trend could be observed from lengthening (7.7 ± 2.7 ,mol , P muscle,1) to isometric (8.9 ± 2.2 ,mol , P muscle,1) to shortening contractions (10.4 ± 1.6 ,mol , P muscle,1). The ratio of high-energy phosphate consumption to force,time-integral was significantly lower for lengthening [0.3 ± 0.1 ,mol , P (N s),1] and isometric [0.6 ± 0.2 ,mol , P (N s),1] contractions compared with shortening [1.2 ± 0.2 ,mol , P (N s),1] contractions (P < 0.05). Conclusion:, The present results of maximally stimulated muscles are comparable with data in the literature for voluntary human exercise showing that the energy cost of force production during lengthening exercise is ,30% of that in shortening exercise. The present study suggests that this finding in humans probably does reflect intrinsic muscle properties rather than effects of differential recruitment and/or coactivation. [source] Powered Liposuction: An Evaluation of Currently Available InstrumentationDERMATOLOGIC SURGERY, Issue 5 2002Timothy Corcoran Flynn MD background. Over the past several years, powered liposuction instruments have become available to the dermatologic surgeon. These instruments all move the cannula forward and backward 2,12 mm with rapidity. This motion simulates the standard human movement of the cannula and facilitates movement through the tissue. Powered liposuction may help to prevent surgeon fatigue and has recently been shown to aid in the efficacy of fat removal. objective. To compare and contrast currently available powered liposuction instruments, to obtain objective engineering data on the instruments, and to compare the instruments when used on actual liposuction cases. methods. Five currently available powered liposuction systems were evaluated by the author. Each instrument was used with a 3 mm dual side port cannula on patients undergoing tumescent liposuction. An independent engineering firm, who collected objective measurements such as weight, stroke force, temperature, and vibration measurements on the instruments, evaluated the units. Noise measurements were obtained. results. Each of the five systems showed advantages and disadvantages. Important issues were the size and weight of the units, as well as whether they were driven electrically or pneumatically. Stroke force is variable (range 9.5,30 pounds). The noise of the units ranged between 60 and 87 dB. Vibration measurements varied from instrument to instrument. Units produced a variable amount of heat ranging from 77°F to 102°F. Most instruments are autoclavable, and one system is disposable. Build quality and reliability varied with the instrument. conclusion. Instruments for powered liposuction have emerged in the last 2 years, with each instrument having distinct advantages and disadvantages. This article reviews five currently available powered liposuction instruments and presents objective measurements as well as the author's experience using the instruments. [source] Integrating modelling and experiments to assess dynamic musculoskeletal function in humansEXPERIMENTAL PHYSIOLOGY, Issue 2 2006J. W. Fernandez Magnetic resonance imaging, bi-plane X-ray fluoroscopy and biomechanical modelling are enabling technologies for the non-invasive evaluation of muscle, ligament and joint function during dynamic activity. This paper reviews these various technologies in the context of their application to the study of human movement. We describe how three-dimensional, subject-specific computer models of the muscles, ligaments, cartilage and bones can be developed from high-resolution magnetic resonance images; how X-ray fluoroscopy can be used to measure the relative movements of the bones at a joint in three dimensions with submillimetre accuracy; how complex 3-D dynamic simulations of movement can be performed using new computational methods based on non-linear control theory; and how musculoskeletal forces derived from such simulations can be used as inputs to elaborate finite-element models of a joint to calculate contact stress distributions on a subject-specific basis. A hierarchical modelling approach is highlighted that links rigid-body models of limb segments with detailed finite-element models of the joints. A framework is proposed that integrates subject-specific musculoskeletal computer models with highly accurate in vivo experimental data. [source] A multimodal fusion system for people detection and trackingINTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 2 2005Mau-Tsuen Yang Abstract Because a people detection system that considers only a single feature tends to be unstable, many people detection systems have been proposed to extract multiple features simultaneously. These detection systems usually integrate features using a heuristic method based on the designers' observations and induction. Whenever the number of features to be considered is changed, the designer must change and adjust the integration mechanism accordingly. To avoid this tedious process, we propose a multimodal fusion system that can detect and track people in a scalable, accurate, robust, and flexible manner. Each module considers a single feature and all modules operate independently at the same time. A depth module is constructed to detect people based on the depth-from-stereo method, and a novel approach is proposed to extract people by analyzing the vertical projection in each layer. A color module that detects the human face, and a motion module that detects human movement are also developed. The outputs from these individual modules are fused together and tracked over time, using a Kalman filter. © 2005 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 15, 131,142, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20046 [source] Pacific ,Babes': issues in the origins and dispersal of Pacific pigs and the potential of mitochondrial DNA analysis,INTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 1-2 2001Melinda S. Allen Abstract We explore potential sources of genetic variation in Pacific pigs over the duration of their commensal relationships with Pacific people. Three time periods are identified as critical to understanding the history of pigs in the Pacific region: (1) the late Pleistocene,early Holocene following from human movement into Near Oceania; (2) with Lapita colonization of Remote Oceania beginning ca. 3000 bp, and (3) in Polynesia, shortly after sustained Euro-American contact (ca. late 1700s) when several new breeds were introduced into the region. This paper highlights the important role mitochondrial DNA (mtDNA) work can play in detailing the origins, directions, and frequency of pig transfers, and by extension, the movements of their human carriers. Our preliminary molecular studies identify a hypervariable region of mtDNA in the genus Sus, rendering it an ideal taxon for detailed study of the issues we raise herein. Copyright © 2001 John Wiley & Sons, Ltd. [source] Bereitschaftspotential and movement-related potentials: Origin, significance, and application in disorders of human movementMOVEMENT DISORDERS, Issue 5 2007James G. Colebatch MB Abstract The existence of a slow negative wave, the Bereitschaftspotential ("BP"), preceding voluntary movement by 1 second or more was first reported more than 40 years ago. There appears to be considerable interindividual differences, but there is general agreement that the initial negativity actually consists of two distinct phases. Uncertainty remains about many other properties and features of the response, including nomenclature, which makes the existing literature difficult to synthesize. The duration of the premovement negativity raises questions about how and when voluntary movement is initiated. Premovement negativities can also be seen before (predictably) externally paced movement, and these have similarities to the BP. Although lateralized generators exist, it is likely that the majority of the early component of the BP (BP1 or early BP), arises from the anterior supplementary motor area (SMA) and more rostral pre-SMA. The late phase of the BP (BP2 or late BP) is probably generated by activity in both the SMA proper and the contralateral motor cortex. Changes in the BP occur in several movement disorders, notably Parkinson's disease, in which the pattern is consistent with a failure of pre-SMA activation. The presence (or absence) of a clear preceding negativity can also have diagnostic importance for certain movement disorders. © 2007 Movement Disorder Society [source] Of crustacean blood and ant infection: Life in the migration exclusion zone, Christmas Island, AustraliaTHE AUSTRALIAN JOURNAL OF ANTHROPOLOGY, Issue 2 2009Simone Dennis This paper is framed by the cultural politics of nationhood in contemporary Australia and particularly by the ways in which the nation has sought to produce borders that have manifested themselves as altered cartographic boundaries and exclusion zones. The paper itself is concerned with life on Christmas Island, and is focused on the ways in which multiethnic Christmas Island locals use blood metaphors drawn from the Island's native Christmas Island red crabs and alien, predatory yellow ants, to articulate patterns of human movement and migration into island space. The metaphors reveal coalescences between the body of the self, the other, nature, and the island place. I explore these coalescences to present a picture of migration and movement from the perspective of those who live within the migration exclusion zone. [source] Human motion reconstruction from monocular images using genetic algorithmsCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 3-4 2004Jianhui Zhao Abstract This paper proposed an optimization approach for human motion recovery from the un-calibrated monocular images containing unlimited human movements. A 3D skeleton human model based on anatomy knowledge is employed with encoded biomechanical constraints for the joints. Energy Function is defined to represent the deviations between projection features and extracted image features. Reconstruction procedure is developed to adjust joints and segments of the human body into their proper positions. Genetic Algorithms are adopted to find the optimal solution effectively in the high dimensional parameter space by simultaneously considering all the parameters of the human model. The experimental results are analysed by Deviation Penalty. Copyright © 2004 John Wiley & Sons, Ltd. [source] Tool hoards and Neolithic use of the landscape in north-eastern IrelandOXFORD JOURNAL OF ARCHAEOLOGY, Issue 1 2004Douglas B. Bamforth Summary. Archaeologists frequently suggest that the Neolithic occupants of Ireland and Britain may not have been fully settled farmers, but were, instead, at least partially nomadic pastoralists. However, human use of any landscape is more complex than the current debate suggests, and this debate has included few systematic studies designed to evaluate this issue in detail. This paper examines hoards (or ,caches') of flaked stone tools in County Antrim, Ireland, to consider the links between anticipatory tool storage and human land-use patterns. Our data imply regular human movements over the study area, possibly linked to transhumant use of different altitudinal zones, with functionally and, sometimes, technologically specific classes of tools stored in different areas. However, the larger context of data on the Irish Neolithic clearly indicates that these movements were part of a way of life centred on permanent horticultural homesteads. [source] | ||||||||||||||||