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Does use of a virtual environment change reaching while standing in patients with traumatic brain injury?

Schafer AY, Ustinova KI - J Neuroeng Rehabil (2013)

Bottom Line: Virtual reaches were compared with reaches-to-point to a target in an equivalent physical environment.The results suggest that visual perception in the VE differs from real-world perception and the performance of functional tasks (e.g., reaching while standing) can be changed in TBI patients, depending on the viewing angle.Accordingly, the viewing angle is a critical parameter that should be adjusted carefully to achieve maximal therapeutic effect during practice in the VE.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physical Therapy, Central Michigan University, Mount Pleasant, MI, USA.

ABSTRACT

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. The hedge was projected on a flat screen and viewed in 3D format in 1 of 3 angles: 10° above horizon (resembling a real-world viewing angle), 50° above horizon, or 90° above horizon (directly overhead). Participants were instructed to reach with their dominant hand avatar and to touch the farthest flower possible without losing their balance or stepping. Virtual reaches were compared with reaches-to-point to a target in an equivalent physical environment. A set of kinematic parameters was used.

Results: Reaches by patients with TBI were characterized by shorter distances, lower peak velocities, and smaller postural displacements than reaches by control individuals. All participants reached ~9% farther in the VE presented at a 50° angle than they did in the physical environment. Arm displacement in the more natural 10° angle VE was reduced by the same 9-10% compared to physical reaches. Virtual reaches had smaller velocity peaks and took longer than physical reaches.

Conclusion: The results suggest that visual perception in the VE differs from real-world perception and the performance of functional tasks (e.g., reaching while standing) can be changed in TBI patients, depending on the viewing angle. Accordingly, the viewing angle is a critical parameter that should be adjusted carefully to achieve maximal therapeutic effect during practice in the VE.

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Related in: MedlinePlus

Means and standard deviations of the endpoint displacement amplitude (A), and center of mass (COM) displacement (B) in participants with TBI (black bars) and in control subjects (gray bars) during reaches in the physical environment before (PE before) and after (PE after) virtual reaches at 10° (VE 10), 50° (VE 50), or 90° (VE 90). Statistically significant differences were found between reaches with a PE after vs. VE, b PE before vs. VE, and # VE at 10° vs. VE at other angles.
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Figure 3: Means and standard deviations of the endpoint displacement amplitude (A), and center of mass (COM) displacement (B) in participants with TBI (black bars) and in control subjects (gray bars) during reaches in the physical environment before (PE before) and after (PE after) virtual reaches at 10° (VE 10), 50° (VE 50), or 90° (VE 90). Statistically significant differences were found between reaches with a PE after vs. VE, b PE before vs. VE, and # VE at 10° vs. VE at other angles.

Mentions: In terms of individual means, control subjects reached farther and showed a greater COM displacement than participants with TBI (Figure 3A-B). A two-way ANOVA revealed significant differences between the groups in terms of the endpoint displacement amplitude (F1,28 = 24.05, p < 0.01) and COM displacement (F1,28 = 7.55, p < 0.01).


Does use of a virtual environment change reaching while standing in patients with traumatic brain injury?

Schafer AY, Ustinova KI - J Neuroeng Rehabil (2013)

Means and standard deviations of the endpoint displacement amplitude (A), and center of mass (COM) displacement (B) in participants with TBI (black bars) and in control subjects (gray bars) during reaches in the physical environment before (PE before) and after (PE after) virtual reaches at 10° (VE 10), 50° (VE 50), or 90° (VE 90). Statistically significant differences were found between reaches with a PE after vs. VE, b PE before vs. VE, and # VE at 10° vs. VE at other angles.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3733631&req=5

Figure 3: Means and standard deviations of the endpoint displacement amplitude (A), and center of mass (COM) displacement (B) in participants with TBI (black bars) and in control subjects (gray bars) during reaches in the physical environment before (PE before) and after (PE after) virtual reaches at 10° (VE 10), 50° (VE 50), or 90° (VE 90). Statistically significant differences were found between reaches with a PE after vs. VE, b PE before vs. VE, and # VE at 10° vs. VE at other angles.
Mentions: In terms of individual means, control subjects reached farther and showed a greater COM displacement than participants with TBI (Figure 3A-B). A two-way ANOVA revealed significant differences between the groups in terms of the endpoint displacement amplitude (F1,28 = 24.05, p < 0.01) and COM displacement (F1,28 = 7.55, p < 0.01).

Bottom Line: Virtual reaches were compared with reaches-to-point to a target in an equivalent physical environment.The results suggest that visual perception in the VE differs from real-world perception and the performance of functional tasks (e.g., reaching while standing) can be changed in TBI patients, depending on the viewing angle.Accordingly, the viewing angle is a critical parameter that should be adjusted carefully to achieve maximal therapeutic effect during practice in the VE.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physical Therapy, Central Michigan University, Mount Pleasant, MI, USA.

ABSTRACT

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. The hedge was projected on a flat screen and viewed in 3D format in 1 of 3 angles: 10° above horizon (resembling a real-world viewing angle), 50° above horizon, or 90° above horizon (directly overhead). Participants were instructed to reach with their dominant hand avatar and to touch the farthest flower possible without losing their balance or stepping. Virtual reaches were compared with reaches-to-point to a target in an equivalent physical environment. A set of kinematic parameters was used.

Results: Reaches by patients with TBI were characterized by shorter distances, lower peak velocities, and smaller postural displacements than reaches by control individuals. All participants reached ~9% farther in the VE presented at a 50° angle than they did in the physical environment. Arm displacement in the more natural 10° angle VE was reduced by the same 9-10% compared to physical reaches. Virtual reaches had smaller velocity peaks and took longer than physical reaches.

Conclusion: The results suggest that visual perception in the VE differs from real-world perception and the performance of functional tasks (e.g., reaching while standing) can be changed in TBI patients, depending on the viewing angle. Accordingly, the viewing angle is a critical parameter that should be adjusted carefully to achieve maximal therapeutic effect during practice in the VE.

Show MeSH
Related in: MedlinePlus