User Acceptance of a Virtual Reality Beer Pong Intervention in Postoperative Rehabilitation: Exploratory Mixed Methods Study.

Background: Postoperative patients often face pain, reduced mobility, and motivational barriers, while health care systems increasingly struggle with shortages of physiotherapy staff, making the evaluation of digital rehabilitation tools highly relevant. In this context, virtual reality (VR)-based rehabilitation has already shown promise in neurological and musculoskeletal settings, but evidence regarding its acceptance and usability in postoperative inpatient rehabilitation, particularly in surgical settings with potentially older, multimorbid patients, as well as the general acceptance and usability of VR-supported physiotherapy, is still insufficiently investigated. Objective: This exploratory mixed methods study investigated the usability and acceptance of a VR-based rehabilitation application among postoperative patients and physiotherapists in a clinical setting. Secondary objectives were to gather initial data on potential differences in usability across age and gender groups and to explore patients' and physiotherapists' attitudes toward VR as a supplement or replacement for conventional physiotherapy. Methods: This cross-sectional exploratory mixed methods study with prospective participant recruitment and data collection included 35 postoperative inpatients (17 female participants and 18 male participants; age groups: <40, 40-60, and >60 years) and 7 physiotherapists (4 female participants and 3 male participants) recruited from visceral surgery and orthopedic departments. Participants used a VR-based rehabilitation demonstrator ("Beer Pong," apoQlar GmbH) delivered through a head-mounted display (Meta Quest 3) for a standardized 5-minute session involving upper-limb movements and squatting exercises. The System Usability Scale (SUS) and a self-developed questionnaire were used to assess the usability of the whole system and general attitudes toward VR-supported physiotherapy. Usability ratings were analyzed descriptively and using a 2-way ANOVA to test for effects of age group and gender. Descriptive statistics were used to summarize responses on motivation, distraction, supplementation, and preferences regarding VR use. Results: The overall mean SUS score was 73.21 (SD 13.74, 95% CI 68.49-77.93). No significant differences in usability ratings were found between age groups or genders. Most patients (29/35, 83%) agreed that the VR scenario increases motivation, and 92% (32/35) viewed VR exercises as a useful supplement to conventional physiotherapy. Physiotherapists reported an average SUS score of 74.64 (SD 10.04, 95% CI 65.35-83.93) and expressed positive attitudes toward VR implementation, as assessed using a self-developed questionnaire. However, only 20% (7/35) of patients believed VR could replace traditional therapy entirely. Conclusions: The results of this pilot study seem to indicate high acceptance of VR-based rehabilitation applications by patients and physiotherapists in the clinical context of a postoperative setting. As one of the first studies to evaluate VR usability specifically in early postoperative inpatient rehabilitation, this work extends existing evidence beyond previously studied rehabilitation domains. Taken together with the possible potential to increase patients' motivation while relieving work strain on physiotherapists, these findings support further investigation through larger controlled trials to assess long-term usability, clinical efficacy, and integration into routine postoperative clinical care, even for older people.