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virtual reality, postural adjustments

Miguel F Gago, Darya Yelshyna, Estela Bicho, Hélder David Silva, Luís Rocha, Maria Lurdes Rodrigues, Nuno Sousa
BACKGROUND/AIMS: Alzheimer's disease (AD) patients have an impaired ability to quickly reweight central sensory dependence in response to unexpected body perturbations. Herein, we aim to study provoked compensatory postural adjustments (CPAs) in a conflicting sensory paradigm with unpredictable visual displacements using virtual reality goggles. METHODS: We used kinematic time-frequency analyses of two frequency bands: a low-frequency band (LB; 0.3-1.5 Hz; mechanical strategy) and a high-frequency band (HB; 1...
May 2016: Dementia and Geriatric Cognitive Disorders Extra
Darya Yelshyna, Miguel F Gago, Estela Bicho, Vítor Fernandes, Nuno F Gago, Luís Costa, Hélder Silva, Maria Lurdes Rodrigues, Luís Rocha, Nuno Sousa
Postural control is a complex dynamic mechanism, which integrates information from visual, vestibular and somatosensory systems. Idiopathic Parkinson's disease (IPD) patients are unable to produce appropriate reflexive responses to changing environmental conditions. Still, it is controversial what is due to voluntary or involuntary postural control, even less what is the effect of levodopa. We aimed to evaluate compensatory postural adjustments (CPA), with kinematic and time-frequency analyzes, and further understand the role of dopaminergic medication on these processes...
January 1, 2016: Behavioural Brain Research
Prakriti Parijat, Thurmon E Lockhart, Jian Liu
The objective of the study was to design a virtual reality (VR) training to induce perturbation in older adults similar to a slip and examine the effect of the training on kinematic and muscular responses in older adults. Twenty-four older adults were involved in a laboratory study and randomly assigned to two groups (VR training and control). Both groups went through three sessions including baseline slip, training, and transfer of training on slippery surface. The training group experienced 12 simulated slips using a visual perturbation induced by tilting a VR scene while walking on the treadmill and the control group completed normal walking during the training session...
February 2015: IEEE Transactions on Bio-medical Engineering
A Kubicki, F Bonnetblanc, G Petrement, F Mourey
BACKGROUND: Postural control associated with self-paced movement is critical for balance in frail older adults. The present work aimed to investigate the effects of a 2D virtual reality-based program on postural control associated with rapid arm movement in this population. METHODS: Participants in an upright standing position performed rapid arm-raising movements towards a target. Practice-related changes were assessed by pre- and post-test comparisons of hand kinematics and centre-of-pressure (CoP) displacement parameters measured in a training group and a control group...
January 2014: Neurophysiologie Clinique, Clinical Neurophysiology
Amanda Y Schafer, Ksenia I Ustinova
BACKGROUND: Although numerous virtual reality applications have been developed for sensorimotor retraining in neurologically impaired individuals, it is unclear whether the virtual environment (VE) changes motor performance, especially in patients with brain injuries. To address this question, the movement characteristics of forward arm reaches during standing were compared in physical and virtual environments, presented at different viewing angles. METHODS: Fifteen patients with traumatic brain injuries (TBI) and 15 sex- and age-matched healthy individuals performed virtual reaches in a computer-generated courtyard with a flower-topped hedge...
2013: Journal of Neuroengineering and Rehabilitation
Kuei-Jung Su, Wen-Juh Hwang, Ching-yi Wu, Jing-Jing Fang, Iat-Fai Leong, Hui-Ing Ma
Research has shown that moving targets help Parkinson's disease (PD) patients improve their arm movement while sitting. We examined whether increasing the speed of a moving ball would also improve standing postural control in PD patients during a virtual reality (VR) ball-catching task. Twenty-one PD patients and 21 controls bilaterally reached to catch slow-moving and then fast-moving virtual balls while standing. A projection-based VR system connected to a motion-tracking system and a force platform was used...
January 2014: Gait & Posture
Andrej Krpič, Arso Savanović, Imre Cikajlo
Telerehabilitation can offer prolonged rehabilitation for patients with stroke after being discharged from the hospital, whilst remote diagnostics may reduce the frequency of the outpatient services required. Here, we compared a novel telerehabilitation system for virtual reality-supported balance training with balance training with only a standing frame and with conventional therapy in the hospital. The proposed low-cost experimental system for balance training enabling multiple home systems, real-time tracking of task's performance and different views of captured data with balance training, consists of a standing frame equipped with a tilt sensor, a low-cost computer, display, and internet connection...
June 2013: International Journal of Rehabilitation Research. Revue Internationale de Recherches de Réadaptation
Shawn M O'Connor, Henry Z Xu, Arthur D Kuo
Step-by-step variations occur during normal human walking, induced in part by imperfect sensorimotor control and naturally occurring random perturbations. These effects might increase energy expenditure during walking, because they differ from the nominal preferred gait, which is typically the most economical, and because of the cost of making active feedback adjustments to maintain gait stability. We tested this hypothesis by artificially inducing greater step variability through visual perturbations from a virtual reality display, and measuring the effect on energy expenditure...
May 2012: Gait & Posture
D Boersma, O Demontiero, Z Mohtasham Amiri, S Hassan, H Suarez, D Geisinger, P Suriyaarachchi, A Sharma, G Duque
OBJECTIVES: Postural instability (PI) is an important risk factor for falls, especially in the frail older population. In this study, we investigated the impact of vitamin D deficiency on PI in a sample of community dwelling older subjects. Our objective was to determine the potential association between vitamin D deficiency and PI in older fallers. DESIGN: Cross-sectional study. SETTING: Falls and Fractures Clinic, Department of Geriatric Medicine, Nepean Hospital, Penrith, Australia...
March 2012: Journal of Nutrition, Health & Aging
Alexandre Kubicki, Geoffroy Petrement, François Bonnetblanc, Yves Ballay, France Mourey
BACKGROUND: Postural control associated with self-paced movement is critical for balance in older adults. The present study aimed to investigate the effects of a virtual reality-based program on the postural control associated with rapid arm movement in this population. METHODS: From an upright standing position, participants performed rapid arm-raising movements toward a target. Practice-related changes were assessed by pre- and posttest comparisons of hand kinematics and center of pressure displacement parameters measured in a training group (mean age: 71...
February 2012: Journals of Gerontology. Series A, Biological Sciences and Medical Sciences
B Marques, G Colombo, R Müller, M R Dürsteler, V Dietz, D Straumann
We investigated the influence of vestibular (caloric ear irrigation) and visual (optokinetic) stimulation on slow and fast split-belt walking. The velocity of one belt was fixed (1.5 or 5.0-6.0 km/h) and subjects (N = 8 for vestibular and N = 6 for visual experiments) were asked to adjust the velocity of the other belt to a level at which they perceived the velocity of both the belts as equal. Throughout all experiments, subjects bimanually held on to the space-fixed handles along the treadmill, which provided haptic information on body orientation...
December 2007: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Lars I E Oddsson, Robin Karlsson, Janusz Konrad, Serdar Ince, Steve R Williams, Erika Zemkova
BACKGROUND: There is a need for effective and early functional rehabilitation of patients with gait and balance problems including those with spinal cord injury, neurological diseases and recovering from hip fractures, a common consequence of falls especially in the elderly population. Gait training in these patients using partial body weight support (BWS) on a treadmill, a technique that involves unloading the subject through a harness, improves walking better than training with full weight bearing...
2007: Journal of Neuroengineering and Rehabilitation
Nicoleta Bugnariu, Joyce Fung
BACKGROUND: The maintenance of upright equilibrium is essentially a sensorimotor integration task. The central nervous system (CNS) has to generate appropriate and complex motor responses based on the selective and rapid integration of sensory information from multiple sources. Since each sensory system has its own coordinate framework, specific time delay and reliability, sensory conflicts may arise and represent situations in which the CNS has to recalibrate the weight attributed to each particular sensory input...
2007: Journal of Neuroengineering and Rehabilitation
T Mergner, G Schweigart, C Maurer, A Blümle
The role of visual orientation cues for human control of upright stance is still not well understood. We, therefore, investigated stance control during motion of a visual scene as stimulus, varying the stimulus parameters and the contribution from other senses (vestibular and leg proprioceptive cues present or absent). Eight normal subjects and three patients with chronic bilateral loss of vestibular function participated. They stood on a motion platform inside a cabin with an optokinetic pattern on its interior walls...
December 2005: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Hiroaki Fushiki, Kenji Kobayashi, Masatsugu Asai, Yukio Watanabe
CONCLUSION: Our results indicate that the illusion of self-motion is a significant factor leading to spatial disorientation. OBJECTIVE: Under normal circumstances, self-motion is perceived in response to motion of the head and body. However, under certain conditions, such as virtual reality environments, visually induced self-motion can be perceived even though the subject is not actually moving, a phenomenon known as "vection". The aim of this study was to examine the possible influence of illusory self-rotation (circular vection) on postural adjustments...
January 2005: Acta Oto-laryngologica
S Kuno, T Kawakita, O Kawakami, Y Miyake, S Watanabe
PURPOSE: Human posture is controlled by a combination of vestibular, somatosensory and visual information. This paper is concerned with postural readjustment responses induced by vection. In the visual control of posture, visually-induced perception of self-motion plays an important role and is called vection. Vection is difficult to measure quantitatively because it is a highly subjective phenomenon. HYPOTHESIS: An optokinetic stimulus that moves in depth induces vection...
October 1999: Japanese Journal of Physiology
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