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Angular Movements (angular + movement)

Distribution by Scientific Domains
Life Sciences33%

Selected Abstracts

Measuring movement at the low back

CLINICAL ANATOMY, Issue 2 2002
J. Rice
Abstract The clinical importance of movements of the human spine is increasingly being realized but their measurement is difficult to carry out. Traditionally, measurement of spinal motion focuses on the lumbar spine as the mobile region and movement at the lower thoracic spine is largely ignored. The aim of this study was to test the hypothesis that sagittal movement at the low back is not confined to the lumbar spine. The range of sagittal movement and the amount of skin distraction during trunk flexion was studied in 10 normal subjects. Angular movement in the sagittal plane between the vertebra prominens and S2 ranged between 40° and 83° among the subjects. Concomitant skin distraction showed that a mean of 32% (range 20,41%) of the movement between the upper thorax and sacropelvis occurred cranial to T12. We therefore suggest that the term "low back" should be applied to a series of mobile vertebrae in the lower thoracic and lumbar spines and that motion of this region in the sagittal plane should be considered as the movement of an immobile upper thoracic spine relative to the sacropelvis. Clin. Anat. 15:88,92, 2002. © 2002 Wiley-Liss, Inc. [source]

Reliability of measurement of angular movements of the pelvis and lumbar spine during treadmill walking

PHYSIOTHERAPY RESEARCH INTERNATIONAL, Issue 4 2001
Nicholas Taylor
Abstract Background and Purpose Angular movements of the pelvis and lumbar spine are thought to play an important role in walking. However, little is known about the amount of unpredictable variability in measurement of these movements during human walking. The aim of the present study was to determine the retest reliability of measuring the angular movements of the pelvis and lumbar spine during unimpaired familiarized treadmill walking. Method Retest reliability for 26 subjects without pathology was determined over a one-week interval. Subjects walked on a treadmill at self-selected or a slower speed while measurements of the three-dimensional angular movements were taken with a computer-based video analysis system. Results The frontal plane movements of pelvic list and lumbar lateral flexion (relative to the pelvis) could be measured with high retest reliability at both self-selected and slow walking speeds (intraclass coefficient (ICC) (2,1) , 0.81). In contrast, transverse and sagittal plane movements demonstrated moderate reliability at both speeds (0.37 , ICC (2,1) , 0.76). Averaging the measurement over six strides resulted in increased observed reliability (self-selected walking speed summary Pearson's r = 0.71, slow walking speed summary Pearson's r = 0.79) compared to taking the measurement based on a single stride (self-selected walking speed summary Pearson's r = 0.63, slow walking speed summary Pearson's r = 0.67). Unlike pelvic and lumbar movements (relative to the pelvis), the measurement of lumbar movements (relative to the global reference frame) appeared to depend on whether subjects were walking at self-selected or slow speeds. Conclusions Measurement of pelvic list and lumbar lateral flexion (relative to the pelvis) could be applied with confidence to hypothesis testing about individuals or groups. Movements in the transverse and sagittal planes are unlikely to be appropriate in hypothesis testing about individuals and hence clinical practice, but may still have experimental applications in hypothesis testing about groups. Copyright © 2001 Whurr Publishers Ltd. [source]

On the electrodetection threshold of aquatic vertebrates with ampullary or mucous gland electroreceptor organs

BIOLOGICAL REVIEWS, Issue 3 2007
Rob C. Peters
Abstract Reinterpretation of research on the electric sense in aquatic organisms with ampullary organs results in the following conclusions. The detection limit of limnic vertebrates with ampullary organs is 1 ,Vcm,1, and of marine fish is 20 nVcm,1. Angular movements are essential for stimulation of the ampullary system in uniform d.c. fields. Angular movements in the geomagnetic field also generate induction voltages, which exceed the 20 nVcm,1 limit in marine fish. As a result, marine electrosensitive fish are sensitive to motion in the geomagnetic field, whereas limnic fish are not. Angular swimming movements generate a.c. stimuli, which act like the noise in a stochastic resonance system, and result in a detection threshold in marine organisms as low as 1 nVcm,1. Fish in the benthic space are exposed to stronger electric stimuli than fish in the pelagic space. Benthic fish scan the orientation plane for the maximum potential difference with their raster of electroreceptor organs, in order to locate bioelectric prey. This behaviour explains why the detection threshold does not depend on fish size. Pelagic marine fish are mainly exposed to electric fields caused by movements in the geomagnetic field. The straight orientation courses found in certain shark species might indicate that the electric sense functions as a simple bisensor system. Symmetrical stimulation of the sensory raster would provide an easy way to keep a straight course with respect to a far-field stimulus. The same neural mechanism would be effective in the location of a bioelectric prey generating a near-field stimulus. The response criteria in conditioning experiments and in experiments with spontaneous reactions are discussed. [source]

Reliability of measurement of angular movements of the pelvis and lumbar spine during treadmill walking

PHYSIOTHERAPY RESEARCH INTERNATIONAL, Issue 4 2001
Nicholas Taylor
Abstract Background and Purpose Angular movements of the pelvis and lumbar spine are thought to play an important role in walking. However, little is known about the amount of unpredictable variability in measurement of these movements during human walking. The aim of the present study was to determine the retest reliability of measuring the angular movements of the pelvis and lumbar spine during unimpaired familiarized treadmill walking. Method Retest reliability for 26 subjects without pathology was determined over a one-week interval. Subjects walked on a treadmill at self-selected or a slower speed while measurements of the three-dimensional angular movements were taken with a computer-based video analysis system. Results The frontal plane movements of pelvic list and lumbar lateral flexion (relative to the pelvis) could be measured with high retest reliability at both self-selected and slow walking speeds (intraclass coefficient (ICC) (2,1) , 0.81). In contrast, transverse and sagittal plane movements demonstrated moderate reliability at both speeds (0.37 , ICC (2,1) , 0.76). Averaging the measurement over six strides resulted in increased observed reliability (self-selected walking speed summary Pearson's r = 0.71, slow walking speed summary Pearson's r = 0.79) compared to taking the measurement based on a single stride (self-selected walking speed summary Pearson's r = 0.63, slow walking speed summary Pearson's r = 0.67). Unlike pelvic and lumbar movements (relative to the pelvis), the measurement of lumbar movements (relative to the global reference frame) appeared to depend on whether subjects were walking at self-selected or slow speeds. Conclusions Measurement of pelvic list and lumbar lateral flexion (relative to the pelvis) could be applied with confidence to hypothesis testing about individuals or groups. Movements in the transverse and sagittal planes are unlikely to be appropriate in hypothesis testing about individuals and hence clinical practice, but may still have experimental applications in hypothesis testing about groups. Copyright © 2001 Whurr Publishers Ltd. [source]