Comparison of reaching and grasping kinematics in patients with hemiparesis and in healthy controls in virtual and physical environments

Levin, M.; Magdalon, Eliane Cristina; Michaelsen, Stella Maris; Quevedo, Antônio Augusto Fasolo

doi:10.1109/icvr.2008.4625123

Cited by 7 publications

(5 citation statements)

References 2 publications

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“…Second, it has been recently shown that visual distortions experienced with our apparatus can be successfully replicated in natural settings during both perceptual and grasping tasks (Bozzacchi & Domini, 2015;Domini, Shah, & Caudek, 2011). Third, several studies demonstrate that the movement kinematics recorded in virtual and physical environments are qualitatively equivalent (Levin, Magdalon, Michaelsen, & Quevedo, 2008Magdalon, Michaelsen, Quevedo, & Levin, 2011; but see also Cuijpers, Brenner, & Smeets, 2004.…”

Section: Discussionmentioning

confidence: 74%

Stereovision for action reflects our perceptual experience of distance and depth

2017

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Binocular vision is widely recognized as the most reliable source of 3D information within the peripersonal space, where grasping takes place. Since grasping is normally successful, it is often assumed that stereovision for action is accurate. This claim contradicts psychophysical studies showing that observers cannot estimate the 3D properties of an object veridically from binocular information. In two experiments, we compared a front-to-back grasp with a perceptual depth estimation task and found that in both conditions participants consistently relied on the same distorted 3D representation. The subjects experienced (a) compression of egocentric distances: objects looked closer to each other along the z-axis than they were, and (b) underconstancy of relative depth: closer objects looked deeper than farther objects. These biases, which stem from the same mechanism, varied in magnitude across observers, but they equally affected the perceptual and grasping task of each subject. In a third experiment, we found that the visuomotor system compensates for these systematic errors, which are present at planning, through online corrections allowed by visual and haptic feedback of the hand. Furthermore, we hypothesized that the two phenomena would give rise to estimates of the same depth interval that are geometrically inconsistent. Indeed, in a fourth experiment, we show that the landing positions of the grasping digits differ systematically depending on whether they result from absolute distance estimates or relative depth estimates, even when the targeted spatial locations are identical.

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Section: Discussionmentioning

confidence: 74%

Stereovision for action reflects our perceptual experience of distance and depth

2017

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“…While virtual reality interventions have been used to shape motion in patients with various orthopedic and neurologic impairments (e.g., low back pain, cerebral vascular accident) [9]–[12], there is mixed evidence on how the VRE effects motor behavior [10], [17], [29]. This study provides evidence that the joint excursions used to perform full-body reaches to static targets are dependent on the environment.…”

Section: Discussionmentioning

confidence: 81%

“…Virtual reality has been used to shape motion in patients with various orthopedic and neurologic impairments (e.g., low back pain, cerebral vascular accident) [9]–[13]. The advantage of the VRE is that a variety of visual stimuli can be presented and manipulated in real-time to provide insights into neural control of movement, guide or shape joint motion, and ultimately provide an innovative treatment to improve function and reduce disability.…”

Section: Introduction1mentioning

confidence: 99%

Effects of Real-World Versus Virtual Environments on Joint Excursions in Full-Body Reaching Tasks

Thomas

Leitkam

Applegate

et al. 2016

IEEE J. Transl. Eng. Health Med.

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Starting from an upright standing posture and reaching for a target that requires some forward bending of the trunk can involve many different configurations of the trunk and limb segments. We sought to determine if configurations of the limb and trunk segments during our standardized full-body reaching tasks were influenced by the visual environment. This paper examined movement patterns of healthy participants (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$n=17$ \end{document}, eight female and nine male) performing full body reaching tasks to: 1) real-world targets; 2) virtual targets presented on a 3-D television; and 3) virtual targets presented using a head-mounted display. For reaches performed in the virtual world, the avatar was presented from a third-person perspective for the 3-D television and from a first-person perspective for the head-mounted display. Reaches to virtual targets resulted in significantly greater excursions of the ankle, knee, hip, spine, and shoulder compared with reaches made to real-world targets. This resulted in significant differences in the forward and downward displacements of the whole-body center of mass between the visual environments. Visual environment clearly influences how subjects perform full-body reaching tasks to static targets. Because a primary goal of virtual reality within rehabilitation is often to restore movement following orthopedic or neurologic injury, it is important to understand how visual environment will affect motor behavior. The present findings suggest that the existing game systems that track and present avatars from a third-person perspective elicit significantly different motor behavior when compared with the same tasks being presented from a first-person perspective.

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“…9 ) in 2011 suggested that virtual reality is effective for improving visual sensory functions, in addition to the functional and muscular capacity of the upper limbs, in the case of stroke patients. Further studies by Levin et al 10 ) and by Merians et al 11 ) also found that virtual reality is effective for improving hand and upper limb functions in stroke patients. However, it was difficult to assess the continued effects of such rehabilitation activities, as it was not possible to observe whether the movements regulated at hospitals were properly performed at home.…”

Section: Introductionmentioning

confidence: 92%

Effects of conventional neurological treatment and a virtual reality training program on eye-hand coordination in children with cerebral palsy

2015

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[Purpose] The purpose of the study was to evaluate the effects of conventional neurological treatment and a virtual reality training program on eye-hand coordination in children with cerebral palsy. [Subjects] Sixteen children (9 males, 7 females) with spastic diplegic cerebral palsy were recruited and randomly assigned to the conventional neurological physical therapy group (CG) and virtual reality training group (VRG). [Methods] Eight children in the control group performed 45 minutes of therapeutic exercise twice a week for eight weeks. In the experimental group, the other eight children performed 30 minutes of therapeutic exercise and 15 minutes of a training program using virtual reality twice a week during the experimental period. [Results] After eight weeks of the training program, there were significant differences in eye-hand coordination and visual motor speed in the comparison of the virtual reality training group with the conventional neurological physical therapy group. [Conclusion] We conclude that a well-designed training program using virtual reality can improve eye-hand coordination in children with cerebral palsy.

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Comparison of reaching and grasping kinematics in patients with hemiparesis and in healthy controls in virtual and physical environments

Cited by 7 publications

References 2 publications

Stereovision for action reflects our perceptual experience of distance and depth

Stereovision for action reflects our perceptual experience of distance and depth

Effects of Real-World Versus Virtual Environments on Joint Excursions in Full-Body Reaching Tasks

Effects of conventional neurological treatment and a virtual reality training program on eye-hand coordination in children with cerebral palsy

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