Usability Evaluation of an Electrically Powered Orthopedic Exerciser: Focus Group Interview and Satisfaction Survey Study

Abstract

Background: Musculoskeletal disorders significantly impair physical function and quality of life, necessitating systematic rehabilitation. Electrically powered orthopedic exercisers, such as continuous passive motion devices, are widely used to enhance joint mobility and muscle recovery. However, existing devices often lack advanced functionalities and user-specific adaptability, limiting their effectiveness. To address these shortcomings, the Rebless Pro was developed as a novel device supporting active and passive exercises with personalized treatment programs. Objective: This study aimed to conduct a formative usability evaluation of the Rebless Pro prototype using focus group interviews (FGIs) and satisfaction surveys with health care professionals specializing in rehabilitation medicine. The goal was to identify areas for improvement to enhance the safety, usability, and information clarity of the device. Methods:: Usability evaluation was performed at the National Rehabilitation Center with 10 participants (5 physiatrists and 5 physical therapists) who had prior experience using similar devices. FGIs were conducted to collect qualitative insights into user experiences, while satisfaction surveys provided quantitative data on ease of use of the user interface and identifiability and understanding of information. Data collection focused on identifying risk factors and usability challenges. Results: Three key areas for improvement were identified: (1) product upgrades to ensure patient safety, including adjustments to exercise speed and resistance; (2) hardware and software improvements to improve usability, including adjustments to the location of the emergency button and improvements to the graphical user interface elements; and (3) improvements to the user manual, including detailed contraindications, patient criteria, and clearer operating instructions. Although the mean score of physiatrists (mean 4.463, SD 0.298) was higher than that of physical therapists (mean 4.114, SD 0.829) in terms of the ease of use of the user interface, the difference was not statistically significant (P=.69). Similarly, in the category of identifiability and understanding of information, higher scores were again reported by physiatrists (mean score 4.467, SD 0.506) than by physical therapists (mean 3.733, SD 0.894), but this difference was also not statistically significant (P=.22). Conclusions: Usability evaluation provided actionable insights into improving the Rebless Pro’s safety, usability, and information clarity. To further refine the device, iterative usability evaluations involving both health care professionals and patients are recommended. These efforts are expected to contribute to the development of a safe, effective, and user-friendly electrically powered orthopedic exerciser suitable for commercialization.