Coordination of reach-to-grasp in physical and haptic-free virtual environments

Unusable for stroke survivors, young and healthy. Your doctor will need to look at and use these to come up with stroke protocols. 

• reach-to-grasp (8)
• virtual reality (118)
• virtual reality games (7)
• virtual reality goggles (1)
• virtual reality training (13)
• haptics (26)

 Describes possible solution but lazily offers nothing specific, so useless. 'May be' and 'study' are not what stroke survivors need.

Coordination of reach-to-grasp in physical and haptic-free virtual environments

• Mariusz P. FurmanekEmail authorView ORCID ID profile,
• Luis F. Schettino,
• Mathew Yarossi,
• Sofia Kirkman,
• Sergei V. Adamovich and
• Eugene Tunik

Journal of NeuroEngineering and Rehabilitation201916:78

https://doi.org/10.1186/s12984-019-0525-9

©  The Author(s). 2019

• Received: 14 January 2019
• Accepted: 25 April 2019
• Published: 27 June 2019

Abstract

Background

Virtual reality (VR) offers unprecedented opportunity as a scientific tool to study visuomotor interactions, training, and rehabilitation applications. However, it remains unclear if haptic-free hand-object interactions in a virtual environment (VE) may differ from those performed in the physical environment (PE). We therefore sought to establish if the coordination structure between the transport and grasp components remain similar whether a reach-to-grasp movement is performed in PE and VE.

Method

Reach-to-grasp kinematics were examined in 13 healthy right-handed young adults. Subjects were instructed to reach-to-grasp-to-lift three differently sized rectangular objects located at three different distances from the starting position. Object size and location were matched between the two environments. Contact with the virtual objects was based on a custom collision detection algorithm. Differences between the environments were evaluated by comparing movement kinematics of the transport and grasp components.

Results

Correlation coefficients, and the slope of the regression lines, between the reach and grasp components were similar for the two environments. Likewise, the kinematic profiles of the transport velocity and grasp aperture were strongly correlated across the two environments. A rmANOVA further identified some similarities and differences in the movement kinematics between the two environments - most prominently that the closure phase of reach-to-grasp movement was prolonged when movements were performed in VE.

Conclusions

Reach-to-grasp movement patterns performed in a VE showed both similarities and specific differences compared to those performed in PE. Additionally, we demonstrate a novel approach for parsing the reach-to-grasp movement into three phases- initiation, shaping, closure- based on established kinematic variables, and demonstrate that the differences in performance between the environments are attributed to the closure phase. We discuss this in the context of how collision detection parameters may modify hand-object interactions in VE. Our study shows that haptic-free VE may be a useful platform to study reach-to-grasp movements, with potential implications for haptic-free VR in neurorehabilitation.