Therapists' and prosthesis users' assessments of a virtual reality environment designed for upper limb prosthesis control training.

Abstract

Background: Prosthesis users need extensive training before they can use a electromyography-controlled prosthesis. Virtual reality seems promising to improve training.

Purpose: The aim was to investigate usability, motivation, workload, virtual reality properties and willingness for implementation of a newly developed virtual reality environment for upper limb prosthesis training, and to investigate if therapists and prosthesis users differed in their assessments.

Study design: This study was a cross-sectional study with a mixed-methods design.

Methods: The virtual task was to make cups of coffee to fulfill coffee orders using an virtual electromyography-controlled prosthesis hand. System Usability Scale, Intrinsic Motivation Inventory, Prosthesis-Task Load Index were used to assess the usability, motivation and workload, respectively. A custom-made questionnaire assessed design aspects of the virtual environment. Short interviews were conducted to investigate the feasibility of implementing virtual reality environment in rehabilitation.

Results: Eleven therapists and 11 prosthesis users participated. System Usability Scale scores were above the minimal level of 70, indicating an acceptable system. Intrinsic Motivation Inventory scores were overall high, with perceived competence being significantly lower than importance, enjoyment and usefulness. Prosthesis-Task Load Index scores indicated very little time pressure and stress, little frustration, mental and physical demand and uncertainty, and some conscious processing and visual attention. Therapists scored significantly higher in the subscales conscious processing and visual attention. The current virtual reality environment incorporated most of the design aspects from the questionnaire. All therapists would consider using the virtual reality environment for rehabilitation practice, however further improvements are necessary to facilitate usage and assure robustness of the system.

Conclusions: Therapists and prosthesis users expressed a high usability and motivation for virtual training and experienced an acceptable workload when using the system to train prosthesis control, with no notable differences between the groups. The current virtual environment included important design elements; both end-users would like to integrate virtual reality in rehabilitation practice.