The hand is a communicable agent that operates under a wide range of scenarios in the physical world, but this study indicates a significant departure from conventional behavioral measurement. The hand, in this study is transposed, and directly operative in a 3-dimensional, virtual environment (VE), giving rise to an interdisciplinary study that encompassed cognition, motor behavior (motor learning and motor control) to ascertain grounds for problem-free hand postures, and hand performance in a VE. The VE offers a platform for quantitative measurement on the execution of a hand posture because it could map the activity in a regulated volume - Gesture Editor (Minimal Reality^TM) with a simple 3-dimensional ‘virtual hand’. The manifestation of technical problems, that is system failure of the virtual world system, called for a contingency plan. The emphasis then became qualitative. A case study proceeded, adhering to ethical practice, in accordance with APA guidelines.

The case study employed an able-bodied, right-handed single male subject who was seated for Experiment I, and remained standing in Experiment II. The subject was tethered to and wore a Cyberglove^TM - whole hand input (WHI) even though the system had expired. The WHI would in effect measure and record the displacement (abduction-adduction, flexion-extension) and rotation of one, or all extensors about the hand, and body of the hand (including the wrist) in accordance to which sensors mounted on the dorsal surface of the WHI were active. The investigator provided no other cue, other a visual stimulus to the subject in the form of an A4 sized photographic image of the required hand posture. The subject then aimed to reproduce the hand posture via their own hand-wrist-forearm performance [1] and maintain it for a period of not less than three seconds. A single video camcorder was used in two planes: sagittal and frontal in experiments I and II for analysis and review. On completion of the execution of a hand posture, the investigator posed pre-scrutinized questions to the subject on those preceding events. The qualitative investigation covered several issues with regard to a hand posture:

• Whole, i.e. complete hand patterns
• Discrete articulation, i.e. fine articulation of one, to at least three extensors
• Subjective appraisal on the ergonomics of an arbitrary hand posture-comfort/difficulty
• Memory, retention (forgetfulness) of a hand posture
• Questionnaire directed to the subject with regard to executing each hand posture

The qualitative nature of the investigation provided information on measuring, assessing and selecting a hand posture for the proposed implementation within a virtual environment.

References

1. Bull, P.E. (1987). Posture & Gesture: International Series in Experimental Social Psychology. New York: Pergamon Press.