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Trivedi Hari H WH Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University, 313 Ferst Drive, Atlanta, GA 30332-0535, - - 2010
To study the interaction between feedforward and feedback modes of postural control, we investigated postural responses during unexpected perturbations of the support surface that occurred during forward reaching in a standing position. We examined postural responses in lower limb muscles of nine human subjects. Baseline measures were obtained when subjects ...
Hall Leanne M - - 2010
Anticipatory postural adjustments (APAs) serve to stabilize posture prior to initiation of voluntary movement. This study examined the effects of changes in postural support on APAs using novel and familiar support paradigms. We also investigated whether postural strategies were refined with practice and how the CNS responded when multiple supports ...
Sienko Kathleen H - - 2010
This study uses frequency-domain techniques and stabilogram diffusion analysis (SDA) to investigate the effect of vibrotactile feedback during continuous multidirectional perturbations of a support platform. Eight subjects with vestibular deficits were subjected to two-axis pseudorandom surface platform motion while donning a multiaxis vibrotactile feedback device that mapped body tilt estimates ...
DiDomenico Angela - - 2010
The effects of single-handed load holding, length of the base of support, and standing surface condition (narrow and wide construction beams) on balance were investigated in twenty-three healthy men between the ages of 18 and 55 years old. Balance during quiet standing was evaluated from postural sway measurements derived from ...
Vette Albert H - - 2010
Measures of postural steadiness - known as posturography - are commonly used for balance assessment during quiet standing. Although quiet sitting balance may be studied via posturography as well, this has not been done to date. As such, the purpose of this study was to characterize the posturography during quiet ...
Van Ooteghem Karen K Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada. - - 2009
Healthy older adults were repeatedly exposed to continuous, variable amplitude oscillations of the support surface to determine (1) whether age affects the capacity for postural motor learning under continuous perturbation conditions with limited predictability and (2) whether practice leads to modifications in the control strategy used to maintain balance in ...
Fujino Sachiko - - 2010
Studies on the relationship between dental occlusion and body balance have suggested that occlusion status contributes to the maintenance of postural balance. However, little has been reported about the effects of voluntary teeth clenching on the stabilization of postural stance in novel environments. In the present study we investigated whether ...
Ruget Hélène H Laboratoire Neurobiologie de la Cognition, CNRS and Aix-Marseille Université, 3 place Victor Hugo, 13331, Marseille cedex 3, - - 2010
A synergistic inclination of the whole body towards the supporting leg is required when producing a stepping movement. It serves to shift the centre of mass towards the stance foot. While the importance of sensory information in the setting of this postural adjustment is undisputed, it is currently unknown the ...
Johannsen Leif - - 2009
Previous researchers have shown that light touch contact with a fixed object reduces body sway, whereas light touch with a moving object entrains and increases sway. Given the importance of interpersonal touch and, for example, its use in care for the elderly, it is interesting to ask whether light touch ...
Stoffregen Thomas A - - 2009
BACKGROUND: On land, the distance and angle between the feet in side-by-side stance tend to have characteristic values. Ship motion mandates changes in the control of stance, but there have been no direct assessments of how stance width and angle are controlled at sea. We predicted that participants would adopt ...
Stack Brendan - - 2009
Balance is defined as a state of equilibrium or parity characterized by cancellation of all forces by equal opposing factors. This is the act of maintaining an upright posture (static balance) or in locomotion (dynamic balance or gait). This system depends on vestibular function, vision, and proprioception to maintain posture, ...
Reynolds Raymond Francis RF School of Sports and Exercise Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, UK. - - 2010
Electrical stimulation of the human vestibular nerve evokes a postural response which, unlike visually evoked sway, is unaffected by stimulus predictability. However, responses can be modified by changes in the level of background sway. Here, the effect of voluntary changes in sway magnitude upon the response to vestibular stimulation is ...
Laurens J - - 2010
Stationary visual information has a stabilizing effect on posture, whereas moving visual information is destabilizing. We compared the influence of a stationary or moving fixation point to the influence of stationary or moving large-field stimulation, as well as the interaction between a fixation point and a large-field stimulus. We recorded ...
Esposti Roberto - - 2010
When oscillating the upper limbs in the horizontal plane, the effort required to maintain posture is higher when the limbs move isodirectionally (ISO coupling) than when they move mirror symmetrical, i.e., antidirectionally (ANTI). Movements stability and accuracy are much lower in ISO than in ANTI and the higher postural requests ...
Turesson H??kan - - 2009
The adoption of postures as a response to threats is often interpreted in terms of predator detection or signalling (e.g. vigilance and defence display). The possibility that an alternative or additional function of anti-predator postures might be to enhance the subsequent escape has been largely unexplored. Here, we use black ...
Kim Seyoung S Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 335 Gwahak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea. - - 2009
Many differences in postural responses have been associated with age and Parkinson's disease (PD), but until now there has been no quantitative model to explain these differences. We developed a feedback control model of body dynamics that could reproduce the postural responses of young subjects, elderly subjects, and subjects with ...
Huffman J L - - 2009
Although it is well established that postural threat modifies postural control, little is known regarding the underlying mechanism(s) responsible for these changes. It is possible that changes in postural control under conditions of elevated postural threat result from a shift to a more conscious control of posture. The purpose of ...
Patel Biren A - - 2009
Terrestrial mammals are characterized by their digitigrade limb postures, which are proposed to increase effective limb length (ELL) to achieve preferred or higher locomotor speeds more efficiently. Accordingly, digitigrade postures are associated with cursorial locomotion. Unlike most medium- to large-sized terrestrial mammals, terrestrial cercopithecine monkeys lack most cursorial adaptations, but ...
Rougier P R - - 2009
Wearing sport shoes inducing ankle dorsiflexion has been shown to alter the biomechanical specificities of the stretched muscles. The possible effect over the short and long term upon the sensorial capacities induced by such stretching has not been addressed yet. Fourteen healthy individuals were involved to assess the proprioceptive repercussion ...
Peterka Robert J - - 2009
There is considerable recent interest in developing humanoid robots. An important substrate for many motor actions in both humans and biped robots is the ability to maintain a statically or dynamically stable posture. Given the success of the human design, one would expect there are lessons to be learned in ...
Tahboub Karim A - - 2009
This article presents a biologically-inspired framework for humanoid postural control. It complies with the main features of human postural control that are extracted from recent studies. In this article, the human body is abstracted as a single-inverted pendulum jointed with a foot that rests freely on a supporting surface. In ...
Castellini Claudio - - 2009
The state-of-the-art feed-forward control of active hand prostheses is rather poor. Even dexterous, multi-fingered commercial prostheses are controlled via surface electromyography (EMG) in a way that enforces a few fixed grasping postures, or a very basic estimate of force. Control is not natural, meaning that the amputee must learn to ...
Stoffregen Thomas A - - 2009
The authors asked whether standing posture could be controlled relative to audible oscillation of the environment. Blindfolded sighted adults were exposed to acoustic flow in a moving room, and were asked to move so as to maintain a constant distance between their head and the room. Acoustic flow had direct ...
Campbell A D - - 2009
The purpose of the study was to determine whether the central nervous system (CNS) requires the sensory feedback generated by balance perturbations in order to trigger postural responses (PRs). In Experiment 1, twenty-one participants experienced toes-up support-surface tilts in two blocks. Control blocks involved unexpected balance perturbations whereas an auditory ...
Pfau Thilo - - 2009
When animals carry loads, there is a proportionate increase in metabolic cost, and in humans this increase in cost is reduced when the load is elastically coupled to the load bearer. Major horse race times and records improved by 5 to 7% around 1900 when jockeys adopted a crouched posture. ...
Omkar Sn - - 2009
Sun salutation is a part of yoga. It consists of a sequence of postures done with synchronized breathing. The practice of few cycles of sun salutation is known to help in maintaining good health and vigor. The practice of sun salutation does not need any extra gadgets. Also it is ...
Le Bozec Serge - - 2009
The aim of this paper was to examine the role of the upper and lower body on the dynamic phenomena, which precede the voluntary movement (anticipatory postural adjustments: APAs), and the way in which they contribute to postural control. In this view, sitting subjects were asked to perform horizontal two-handed ...
Moraes Renato - - 2009
The goal of this study was to examine the coupling between visual information and body sway with binocular and monocular vision at two distances from the front wall of a moving room. Ten participants stood as still as possible inside of a moving room facing the front wall in conditions ...
Goodworth Adam D - - 2009
We investigated the influence of feedback conditions on the effectiveness of a balance prosthesis. The balance prosthesis used an array of 12 tactile vibrators (tactors) placed on the anterior and posterior surfaces of the torso to provide body orientation feedback related to several different combinations of angular position and velocity ...
Milton John - - 2009
The inverted pendulum is frequently used as a starting point for discussions of how human balance is maintained during standing and locomotion. Here we examine three experimental paradigms of time-delayed balance control: (1) mechanical inverted time-delayed pendulum, (2) stick balancing at the fingertip, and (3) human postural sway during quiet ...
Padula William V WV Padula Institute of Vision, 37 Soundview Road, Guilford, CT 06437, USA. - - 2009
To demonstrate that Visual Midline Shift Syndrome (VMSS) following a cerebrovascular accident (CVA) can be corrected with yoked prisms. This randomized study describes how the use of yoked prisms affects visual midline and documents the influence of yoked prisms on improving postural orientation. Evaluation of VMSS and its correlation with ...
Page Alvaro - - 2009
This paper presents a new approach for analysing trunk kinematics in sitting posture based on the characterisation of thorax and pelvis motion by means of ranges of motion and instantaneous axes of rotation (IAR). These variables are estimated from videophotogrammetric data. An experiment was carried out in order to analyse ...
Hwang Sungjae - - 2009
Falls are one of the main concerns of the elderly. Proper postural adjustments to maintain balance involve the activation of appropriate muscles to produce force and to relocate the center of body mass (CoM). In this study, biomechanical aspects of dynamic postural responses against forward perturbations were experimentally determined by ...
Murnaghan Chantelle D - - 2009
To maintain balance during movements such as bending and reaching, the CNS must generate muscle forces to counteract destabilizing torques produced by gravitational (position-dependent) and inertial (acceleration-dependent) forces. This may create a trade-off between the attainable frequency and amplitude of movements. We used experiments and mathematical modeling to examine this ...
Barra J - - 2009
BACKGROUND: Weakness and somatosensory deficits have long been known to be involved in the postural instability of subjects with stroke. Recently, it has been shown that impaired representations of the orientation of the longitudinal axis of the body (LBA, egocentric reference) and of verticality (allocentric reference) may also play a ...
Wood Scott J - - 2009
The purpose of this study was to assess the influence of electrotactile feedback on postural control performance during binaural galvanic vestibular stimulation (GVS). Postural equilibrium was measured with a computerized hydraulic platform in 10 healthy adults (6M, 4F, 24-65 y). Feedback of anterior-posterior (AP) and mediallateral (ML) body sway was ...
Horlings C G C - - 2009
Movement strategies controlling quiet stance and rapid balance corrections may have common characteristics. We investigated this assumption for lower leg proprioceptive loss (PL), peripheral vestibular loss (VL), and healthy controls. Our underlying hypothesis was that changes in movement-strategy modulation following sensory loss would improve with prosthetic biofeedback. Quiet stance was ...
Horak Fay B FB Department of Neurology, Oregon Health and Science University, Portland, Oregon 97006, USA. - - 2009
To what extent can remaining sensory information and/or sensory biofeedback (BF) compensate for loss of vestibular information in controlling postural equilibrium? The primary role of the vestibulospinal system is as a vertical reference for control of the trunk in space, with increasing importance as the surface becomes increasingly unstable. Our ...
Yi Yongwoo Y Department of Mechanical Engineering, KAIST, Yuseong-gu, Daejeon, Republic of Korea. - - 2009
To investigate whether the sensory perception could be a more direct assessment of sensory deficit as oppose to the postural performance, we examined the effect of reduced cutaneous cues on motion perception and motion control. The subject was translated in a mediolateral direction with a single sinusoidal acceleration at a ...
Goodworth Adam D - - 2009
The control of upper body (UB) orientation relative to the pelvis in the frontal plane was characterized by analyzing responses to external perturbations consisting of continuous pelvis tilts (eyes open [EO] and eyes closed [EC]) and visual surround tilts (EO) at various amplitudes. Lateral sway of the lower body was ...
Błaszczyk Janusz W - - 2009
Research that evaluated both static and dynamic stability was performed, to clarify the impact of excessive body weight on postural control. The spontaneous center of foot pressure (CP) motion during quiet stance and a range of forward voluntary CP displacements were studied in 100 obese, and 33 lean women. Characteristics ...
Barela Ana M F - - 2009
This study examined the influence of both optic flow characteristics and intention on postural control responses. Two groups of 10 adults each were exposed to the room's movement either at 0.6 cm/s (low velocity group) or 1.0 cm/s (high velocity group). All the participants stood in the upright stance inside ...
Yiou Eric - - 2009
This study investigated how young healthy subjects control their equilibrium in situations of instability specifically elicited by a reduced capacity of force production in the postural muscle system. Ten subjects displaced a bar forward with both hands at maximal velocity toward a target while standing on the dominant leg (UNID), ...
Albright Bruce C - - 2009
Shoes with rocker bottom soles are utilized by persons with diabetic peripheral neuropathy to reduce plantar pressures during gait. This population also has a high risk for falls. This study analyzed the effects of shoes with rocker bottom soles on the postural response during perturbed stance. Participants were 20 healthy ...
Oude Nijhuis Lars B - - 2009
Support-surface movements are commonly used to examine balance control. Subjects typically receive a series of identical or randomly interspersed multidirectional balance perturbations and the atypical "first trial reaction" (evoked by the first perturbation) is often excluded from further analysis. However, this procedure may obscure vital information about neurophysiological mechanisms associated ...
van den Heuvel Maarten R C - - 2009
We performed an experiment in which we challenged postural stability in 12 healthy subjects by providing artificial delayed visual feedback. A monitor at eye-height presented subjects with a visual representation of the location of their center-of-pressure (COP) and they were instructed to position their COP as accurately as possible on ...
Geffen Paul van - - 2009
Individuals who cannot functionally reposition themselves often need dynamic seating interventions that change body posture from automatic chair adjustments. Pelvis alignment directly affects sitting posture, and systems that adjust and monitor pelvis angle simultaneously might be applicable to control body posture in sitting. The present study explores whether it is ...
Cnyrim Christian C Neurological University Clinics, Neurozentrum, Breisacher Str. 64, 79106, Freiburg, - - 2009
Human stance is inherently unstable. A small deviation from upright body orientation is enough to yield a gravitational component in the ankle joint torque, which tends to accelerate the body further away from upright ('gravitational torque'; magnitude is related to body-space lean angle). Therefore, to maintain a given body lean ...
Fux Michal - - 2009
Aiming at the question of whether barn owls favor to strike a moving or a stationary prey, we scrutinized the timing of launching 50 attacks of five barn owls (10 attacks/owl) in a captive environment. Attacks on stationary voles outnumbered attacks on moving voles, but this could merely reflect the ...
Côté Julie N - - 2009
Previous studies have shown that individuals with WAD display decreased postural stability during standing and walking tasks. However, their ability to maintain seated upright posture has never been investigated. The objective of this study was to characterize kinematic and electromyographic postural stabilization patterns in individuals with chronic WAD and to ...
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