Usability and expert validation of a virtual reality system for post-mastectomy rehabilitation

Introduction: Virtual reality (VR) is proposed as a support (and potential alternative) to traditional rehabilitation after breast cancer surgery, with expected effects on pain, anxiety, fatigue, and recovery of shoulder ROM (range of movement). The study aims to test a VR system that integrates body illusion, gamification, and distraction, evaluating its usability, user experience, and comfort for clinical use. Methods: The study was conducted on 31 healthy subjects (28 physiotherapy students, 3 physiotherapists). The software includes a shoulder ROM calibration phase and a training phase involving a VR tennis game, with adjustable parameters and automatic performance recording. SSQ, SUS, UEQ, CRS, and a question on the adequacy of playing speed were administered. A descriptive analysis (mean, standard deviation) and a qualitative analysis of the open-ended responses were conducted. Results: SSQ: very low average symptoms (minimal discomfort). SUS: good perceived usability (easy, integrated, safe). UEQ: Overall positive experience (clarity, modernity, pleasantness); concerns regarding predictability/slowness. CRS: High tolerability and low anxiety/harm; higher "attachment." Regarding speed: 15 "Yes" votes to making it faster, 16 "No" votes (divided opinions). Discussion: The VR system is well tolerated, usable, and has a favorable user experience in healthy subjects, indicating promising clinical transferability for shoulder rehabilitation after breast surgery. Dynamics and predictability (adaptive speed/levels) remain to be optimized, and the software needs to be validated on patients and experienced physiotherapists in dedicated studies.