Immersive Tai Chi for Home-Based Exercise in Older Adults: Usability and Feasibility Study.

Background: Longer life expectancy makes physical exercise crucial for active aging. However, adherence to traditional exercise among community-dwelling older adults is generally low. Virtual reality (VR) and mixed reality (MR) Tai Chi exergames, as novel health promotion tools, show significant potential, particularly for older adults exercising in a home setting. Objective: This study aimed to evaluate the usability and feasibility of a VR and MR Tai Chi exergame for community-dwelling older adults, focusing on subjective experience, physiological comfort, and objective interaction performance. The study also explored the relationships between key usability factors and sought to quantify links between objective accuracy and subjective experience (the Game Experience Questionnaire or Virtual Reality Sickness Questionnaire [VRSQ]) to inform choices of display mode, feedback strength, and session length. Methods: Of the 86 community-dwelling older adults recruited for this study, data from 70 participants were considered valid after an initial screening, during which 16 (18.6%) were excluded due to issues with VR adaptation. Participants were sequentially assigned in a rotating order to 1 of 4 variants (VR/MR×soothing/intense) to balance exposure; however, primary analyses were preplanned to be collapsed across variants, focusing on whole-sample usability and feasibility rather than confirmatory between-group hypotheses. The primary outcome measures included the Game Experience Questionnaire, VRSQ, and objective gameplay logs. Results: The VR/MR Tai Chi game demonstrated good overall usability and acceptability among the screened participants. Subjective experience was highly positive, with median scores for "positive affect" (median 4.0) and "competence" (median 3.8) being significantly high, whereas the median for "Challenge" (median 1.4) was significantly low (P<.001 for all). Physiological comfort in the postscreening sample was acceptable, with the most common mild symptoms being dizziness with eyes closed (20.0%) and vertigo (18.6%), both of low severity; however, the initial exclusion of 18.6% of participants due to VR discomfort is noteworthy. Therefore, generalizability is limited because the analyzed sample overrepresents older adults who tolerate immersive displays. Accuracy showed significant positive correlations with flow (ρ=0.342) and competence (ρ=0.322), whereas the VRSQ total score was significantly negatively correlated with positive affect (ρ=-0.334, P=.005). Conclusions: Tai Chi exergames based on immersive technologies offer a feasible and attractive pathway for promoting physical exercise among community-dwelling older adults, particularly within the home environment, supporting the goal of aging in place. As a single, laboratory-based session, the reported satisfaction may partly reflect a novelty effect; therefore, longer-term, home-based follow-ups are needed to assess durability. Analysis of the key usability factors provides guidance for specific design choices, while also indicating directions for future research, such as longitudinal evaluations, extension to more diverse populations, and application in real-world home settings.