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Results 301 - 350 of 883
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Corazza Stefano - - 2009
The ability of the central nervous system to control posture and balance has been used with increasing frequency for the diagnosis and/or treatment evaluation of various neuromuscular diseases. Typically this analysis (Posturographic Analysis) is based on tracking the motion of the center of mass (COM) during quiet standing, however direct ...
Moya Gabriel Bueno Lahóz - - 2009
The aim of this study was to analyze whether quiet standing posture is related to compensatory postural adjustment. The latest data in clinical practice suggests that static posture may play a significant role in musculoskeletal function, even in dynamic activities. However, no evidence exists regarding whether static posture during quiet ...
Keshner Emily A - - 2009
Orientation in space is a perceptual variable intimately related to postural orientation that relies on visual and vestibular signals to correctly identify our position relative to vertical. We have combined a virtual environment with motion of a posture platform to produce visual-vestibular conditions that allow us to explore how motion ...
Aspell Jane E - - 2009
The spatial unity between self and body can be disrupted by employing conflicting visual-somatosensory bodily input, thereby bringing neurological observations on bodily self-consciousness under scientific scrutiny. Here we designed a novel paradigm linking the study of bodily self-consciousness to the spatial representation of visuo-tactile stimuli by measuring crossmodal congruency effects ...
Song Sa-kwang SK 138 Gajeongno, Yuseong-gu, Daejeon, 305-700, South Korea. - - 2009
We propose a dynamic activity classification system with tri-axial accelerometer sensor using adaptation of user's postural orientation. In general, the sensor module is worn at a fixed position such as waist, head, wrist, thigh, and so on. However, in reality, the tilt of the attached sensor could be changed from ...
Chung Tein-Yaw - - 2009
Positioning and tracking technologies can detect the location and the movement of mobile nodes (MNs), such as cellular phone, vehicular and mobile sensor, to predict potential handoffs. However, most motion detection mechanisms require additional hardware (e.g., GPS and directed antenna), costs (e.g., power consumption and monetary cost) and supply systems ...
Lopez Christophe - - 2009
Since human behavior and perception have evolved within the Earth's gravitational field, humans possess an internal model of gravity. Although gravity is known to influence the visual perception of moving objects, the evidence is less clear concerning the visual perception of static objects. We investigated whether a visual judgment of ...
Haibach Pamela - - 2009
BACKGROUND: Elderly people tend to rely upon their visual input more than upon that from other sensory systems due to age-related declines. This reliance upon vision places older adults at risk for falls because they are often not aware of the magnitude of their body motion. OBJECTIVE: The purpose of ...
Krutky Matthew A MA Sensory Motor Performance Program, The Rehabilitation Institute of Chicago and Department of Biomedical Engineering, Northwestern University, Evanston, IL 60611, - - 2009
Using the upper limb to manipulate objects or tools requires maintenance of stable arm posture. The ability to maintain stable postures is dependent on the mechanical properties of the arm, which can be characterized by estimates of endpoint stiffness. In this study we quantified the endpoint stiffness of the human ...
Roether Claire L - - 2009
Human observers readily recognize emotions expressed in body movement. Their perceptual judgments are based on simple movement features, such as overall speed, but also on more intricate posture and dynamic cues. The systematic analysis of such features is complicated due to the difficulty of considering the large number of potentially ...
Vichare V V VV Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA. - - 2009
This study uses frequency domain techniques to demonstrate the effect of vibrotactile feedback during continuous multidirectional perturbations of a support platform. Eight subjects with bilateral or unilateral vestibular loss were subjected to two-axis pseudo random surface platform motion while donning a multi-axis feedback balance aid that mapped body tilt estimates ...
Cawsey Ryan P - - 2009
Previous research has shown that standing sway can be reduced when real-time visual feedback of the centre of pressure (COP) position is provided and that it can be further reduced when the visual feedback is magnified. The objective of this study was to determine the magnification beyond which there was ...
Uchiyama Masanobu - - 2008
Vision contributes to upright postural control by providing afferent feedback to the cerebellum. Vision is generally classified into central and peripheral vision, but little is known about the respective role of central and peripheral vision for postural control with different visual acuity levels. This study examined the influence of visual ...
Pan Christopher S - - 2009
Stilts are elevated tools that are frequently used by construction workers to raise workers 18-40 inches above the ground. The objective of this laboratory study was to evaluate the potential loss of postural stability associated with the use of stilts in various foot placements. Twenty construction workers with at least ...
Le Bozec Serge - - 2008
Postural adjustments, which occur after the end of a voluntary movement (termed Consecutive Postural Adjustments: CPAs), were studied and compared to the corresponding Anticipatory Postural Adjustments (APAs). Seven right-handed male adults were asked to perform horizontal two-handed maximal ramp pushes as quickly as possible, while sitting. A dynamometric bar measured ...
Mikami Saki - - 2009
To elucidate the influence of motion and posture of head on the newly developed ultraminiature cordless bruxism measurement system (BMS), we examined masseteric electromyographic (EMG) data of BMS during turning-over movements in bed in comparison with those of a conventional polygraph system (PG). Twelve healthy subjects lay on their back ...
Jeka John J JJ Department of Kinesiology, University of Maryland, College Park, MD, USA. - - 2008
Human movement control is inherently stochastic, requiring continuous estimation of self-motion based upon noisy sensory inputs. The nervous system must determine which sensory signals are relevant on a time scale that enables successful behavior. In human stance control, failure to effectively adapt to changing sensory contexts could lead to injurious ...
Freeman Ellen E - - 2008
PURPOSE: The aim of this study was to identify the visual factors associated with various levels of balance ability in a population-based study of older adults. METHODS: Data for this analysis came from the third round of the Salisbury Eye Evaluation population-based cohort study (1505 individuals). Measures of visual function ...
Guerraz Michel M Laboratoire de Psychologie et Neurocognition, CNRS UMR 5105, Université de Savoie, 73376 Le Bourget du lac, France. - - 2008
We investigate the relationship between visually induced perceptual illusions of body motion (vection) and visually induced postural responses (VEPRs). Ten standing healthy subjects were tested in two visual conditions known to induce directionally opposite VEPRs: subjects fixated either a static head-mounted or an earth-fixed visual display in front of a ...
Bremner Andrew J - - 2008
A significant challenge in developing spatial representations for the control of action is one of multisensory integration. Specifically, we require an ability to efficiently integrate sensory information arriving from multiple modalities pertaining to the relationships between the acting limbs and the nearby external world (i.e. peripersonal space), across changes in ...
Ruget H - - 2008
Stepping over an obstacle is preceded by a center of pressure (CoP) shift, termed anticipatory postural adjustments (APAs). It provides an acceleration of the center of mass forward and laterally prior to step initiation. The APAs are characterized in the lateral direction by a force exerted by the moving leg ...
Michel-Pellegrino Valérie - - 2008
BACKGROUND AND AIMS: Changes in sensory- motor systems that occur with age result in a decrease in postural equilibrium, which has been linked with an increased risk of falling in the elderly. Stepping down backwards from a step perturbs dynamic postural equilibrium, thus offering an opportunity to analyze the biomechanical ...
Gutnik Boris - - 2008
Although the identification and characterisation of a participant's lateral profile during quiet standing have not received much research attention, they have the potential to greatly extend our understanding of upright stance stability control. This study further examines limb load asymmetries during quiet bipedal stance. During voluntary frontal-plane weight shifting for ...
Tucker Murray G - - 2008
The elderly are known to exhibit declines in postural control during standing and walking, however little is known about how the elderly react under time-critical and challenging postural situations. The purpose of this study was to examine age-related differences in reaction time (RT) and the pattern of temporal coordination between ...
Kouzaki Motoki M Laboratory of Neurophysiology, Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsu, Sakyo-ku, Kyoto 606-8501, Japan. - - 2008
It is well known that a light and voluntary touch with a fingertip on a fixed surface improves postural stability during quiet standing. To determine whether the effect of the light touch is due to the tactile sensory input, as opposed to mechanical support, we investigated the light touch effect ...
Mahboobin Arash - - 2008
This paper describes mechanisms used by humans to stand on moving platforms, such as a bus or ship, and to combine body orientation and motion information from multiple sensors including vision, vestibular, and proprioception. A simple mechanism, sensory re-weighting, has been proposed to explain how human subjects learn to reduce ...
Robert Thomas T Department of Kinesiology, The Pennsylvania State University, Rec. Hall-268N, University Park, PA 16802, - - 2008
We studied muscle activation patterns in response to perturbations of posture (sudden changes in the external force applied to the thorax) during two time intervals corresponding to pre-programmed postural reactions and voluntary corrections of posture. A hypothesis was tested that a set of postural muscles could be used to form ...
Michel-Pellegrino Valérie - - 2008
The aim of this study was to analyze differences in biomechanical parameters between elderly and control participants when stepping up, to evaluate control of balance. Eleven control and 14 elderly participants performed a step from an initial static posture onto a 7-cm-high force plate. For the spontaneous-velocity condition, elderly participants ...
O'Connor Kathryn W KW Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260, - - 2008
The purpose of this study is to understand the processes of adaptation (changes in within-trial postural responses) and habituation (reductions in between-trial postural responses) to visual cues in older and young adults. Of particular interest were responses to sudden increases in optic flow magnitude. The postural sway of 25 healthy ...
Van Ooteghem K K Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada. - - 2008
We examined changes in the motor organization of postural control in response to continuous, variable amplitude oscillations evoked by a translating platform and explored whether these changes reflected implicit sequence learning. The platform underwent random amplitude (maximum +/- 15 cm) and constant frequency (0.5 Hz) oscillations. Each trial was composed ...
Reed-Jones Rebecca J - - 2008
Currently little is known about how adaptive responses to virtual environments are different between individuals who experience sickness related symptoms and those who do not. It is believed that sensory interactions between visually perceived self-motion and static inertial cues from vestibular and/or proprioceptive sensory systems contribute to the development of ...
Fujiwara Katsuo - - 2009
We investigated the effects of stance width on postural movement pattern and activation timing of postural muscles during unilateral arm abduction. Thirty-two healthy subjects abducted the right arm at their own timing. Stance width was 0, 9, 18 or 27 cm. Movement angles of leg lateral inclination and trunk lateral ...
Dorel S - - 2009
The aim of this study was to test the hypothesis that, in comparison with standard postures, aero posture (AP) would modify the coordination of lower limb muscles during pedalling and consequently would influence the pedal force production. Twelve triathletes were asked to pedal at an intensity near the ventilatory threshold ...
Orlov I V - - 2008
The subjects in this study maintained a vertical posture standing on a rigid support. Postural stability was assessed in terms of the standard deviations (sigma) from the mean amplitude of movements of the head relative to the null coordinate. Feedback at the vestibular input was created by transmastoid bipolar galvanic ...
Wong Wai Yin - - 2008
Measurement of human posture and movement is an important area of research in the bioengineering and rehabilitation fields. Various attempts have been initiated for different clinical application goals, such as diagnosis of pathological posture and movements, assessment of pre- and post-treatment efficacy and comparison of different treatment protocols. Image-based methods ...
Vuillerme Nicolas N Laboratoire TIMC-IMAG, UMR UJF CNRS 5525, Faculté de Médecine, 38706, La Tronche cédex, France. - - 2008
The purpose of the present experiment was to investigate whether postural responses to ankle proprioceptive perturbation Achilles tendon vibration were affected by the availability of augmented sensory information about head orientation/motion with respect to gravitational vertical, i.e., normally provided by the vestibular system. To achieve this goal, ten standing subjects ...
Zabjek Karl F - - 2008
The objective of the present study is to quantify the position of the Centre of Mass (COM) during quiet standing using a force plate and compare this technique to the quantification of the COM with an anthropometric model. The postural control of 18 healthy adolescents and 22 IS patients was ...
Creath Rob R Department of Kinesiology, University of Maryland, College Park, MD 20742-2611, - - 2008
Upright stance was perturbed using sinusoidal platform rotations to see how vestibular and somatosensory information are used to control segment and intersegmental dynamics in subjects with bilateral vestibular loss (BVL) and healthy controls (C). Subjects stood with eyes closed on a rotating platform (+/-1.2 degrees) for frequencies ranging from 0.01-0.4 ...
Sienko K H - - 2008
Single-axis vibrotactile feedback of trunk tilt provided in real-time has previously been shown to significantly reduce the root-mean-square (RMS) trunk sway in subjects with vestibular loss during single-axis perturbation. This research examines the effect of multi-directional vibrotactile feedback on postural sway during continuous multi-directional surface perturbations when the subjects' eyes ...
Rabin Ely - - 2008
Lightly touching a stable surface with one fingertip strongly stabilizes standing posture. The three main features of this phenomenon are fingertip contact forces maintained at levels too low to provide mechanical support, attenuation of postural sway relative to conditions without fingertip touch, and center of pressure (CP) lags changes in ...
Gautier Geoffroy - - 2008
The purpose of the present experiment was to investigate how postural adaptations to the perceptive configuration are modified by specific gymnastics experience. Two groups, one expert in gymnastics and the other non-expert, had to maintain the erected posture while optical flow was imposed as follows: 20s motionless, 30s approaching motion, ...
Saffer Mark M Department of Kinesiology, University of Maryland, College Park, MD 20742-2611, USA. - - 2008
Studies of muscle activation during perturbed standing have demonstrated that the typical patterns of coordination ("ankle strategy" and "hip strategy") are controlled through multiple muscles activated in a distal-to-proximal or proximal-to-distal temporal pattern. In contrast, quiet stance is thought to be maintained primarily through the ankle musculature. Recently, spectral analysis ...
Huang Cheng-Ya - - 2009
The quiet stance is a complicated motor act requiring sophisticated sensorimotor integration to balance an artificial inverted pendulum with the ankle musculature. The objective of this study was to characterize the effects of stance pattern (bilateral stance vs. unilateral stance) and directional influence of light finger touch (medial-lateral vs. anterior-posterior) ...
Fujiwara Katsuo - - 2009
We investigated the effects of neck flexion on contingent negative variation (CNV) and anticipatory postural control using an arm flexion task in standing. CNV was adopted to evaluate the state of activation of brain areas related to anticipatory postural control. Subjects were required to flex the arms in response to ...
Reed-Jones Rebecca J RJ Department of Human Health and Nutritional Sciences, College of Biological Science, University of Guelph, Animal Science/Nutrition Building, Guelph, ON, Canada N1G - - 2007
The role of lower limb proprioception in the steering control of locomotion is still unclear. The purpose of the current study was to determine whether steering control is altered in individuals with reduced lower limb proprioception. Anterior cruciate ligament deficiency (ACLD) results in a decrease in proprioceptive information from the ...
Mork Paul Jarle - - 2007
The study aimed to determine the influence of arm posture and movement on trapezius activity of computer workers, considering the full workday. A second aim was to investigate if work periods perceived as stressful were associated with elevated or more sustained muscle activity pattern. Twenty-six computer workers performing call-center (n=11), ...
Frykberg Gunilla Elmgren GE Department of Neuroscience Rehabilitation Medicine, Uppsala University, University Hospital, Sweden. - - 2007
To explore the correlation between clinical assessment and force plate measurement of postural control after stroke when selected balance tasks are performed under similar spatial and temporal conditions, and to examine the inter-rater agreement of assessment of weight distribution during quiet stance in subjects with stroke. A descriptive and correlational ...
Glover P M PM The Sir Peter Mansfield Magnetic Resonance Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom. - - 2007
Vertigo-like sensations or apparent perception of movement are reported by some subjects and operators in and around high field whole body magnetic resonance body scanners. Induced currents (which modulate the firing rate of the vestibular hair cell), magneto-hydrodynamics (MDH), and tissue magnetic susceptibility differences have all been proposed as possible ...
Hatzitaki Vassilia V Motor Control and Learning Laboratory, Department of Physical Education and Sport Science, Aristotle University of Thessaloniki, 546 24 Thessaloniki, Greece. - - 2007
The effects of aging on the acquisition of a novel visuo-postural coordination task were addressed at two levels: (a) changes in the intersegmental coordination (local dynamics) (b) changes in the coupling of postural sway to the visual driving stimulus (global dynamics). Twelve elderly (age: 71.2 +/- 6.4 years; height: 169.3 ...
Wright W Geoffrey WG Neurological Sciences Institute, Oregon Health and Science University, 505 NW 185th Avenue, Beaverton, OR 97006-3499, USA. - - 2007
The extent to which postural orientation and perception of orientation share common central processes is unknown. If central resources are shared, automatic postural orientation in space and conscious perception of gravitational vertical (GV) or surface horizontal (SH) orientation should vary similarly with changing frequencies of surface tilts. Furthermore, shared central ...
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