## 4 Critical Review of AR and VR Technologies for Older Adults  
### Physical Wellbeing  
Physical wellbeing of older adults refers to the state in which they are capable of performing physical activities or social roles; further, a series of these activities should be free from physical limitations. Physical wellbeing is an important issue in AR and VR studies, encompassing \"motivation,\" \"training,\" \"reminder,\" and \"accessibility.\" VR and AR are concerned with four types of perspectives to support physical wellbeing of older adults. First, training for their lack of ability; second, encouraging an interest in physical activity, applying an engaging factor to the design; third, providing a reminder related to health combined with interaction modality, such as a wearable or mobile device, and lastly, providing good accessibility for them to use AR or VR technologies. VR and AR applications have the merit of simulating various situations for health training and performance testing [46; 47; 48]. [PERSON] et al. [43] created a virtual supermarket through which they explored the potential to use VR technology to assess and train the cognitive aptitude of brain-injured patients with regard to assistive daily living by asking them to complete basic shopping tasks. [PERSON] et al. [44] developed an AR-3 DH system designed to train older adults to refine their mental rotation skills. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Category** & **Factors** & **Clarification** \\ \hline \multirow{6}{*}{Social Wellbeing} & Remote participation & Providing contexts for older adults to participate in social interactions anytime, anywhere without concern about mobility \\ \cline{2-3}  & Virtual interaction & Providing environment to share experiences and to build relationships with other people, such as through human-to-human interaction in the virtual environment \\ \cline{2-3}  & Emotional relationship & Making older adults not feel a sense of difference in emotion in the process of socialization in the virtual environment \\ \cline{2-3}  & Community services & Providing services to avoid inconvenience in sharing and using virtual devices with other people/or serving and supporting the diverse activity potential while using AR and VR systems \\ \hline \multirow{6}{*}{Psychological Wellbeing} & Positive emotions & Arousing positive emotion continuously in the environment using VR and AR \\ \cline{2-3}  & Virtual content & Updating content to retain users’ interest constantly, not temporarily \\ \cline{2-3}  & Independence & Supporting the needs of older people living independently in residential homes and/or assisted-living communities \\ \cline{2-3}  & Environmental mastery & Providing the ability to manage environmental factors and activities in an environment in which VR supports daily activities \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._[PERSON] et al. [46] and [PERSON] et al. [47] designed a system combining AR and gamification to support elderly persons' rehabilitation activities. Among older adults with a mental problem, even a small mistake may lead to a severe accident. One main advantage of using AR and VR for enhancing physical wellbeing is that these applications enable them to engage in physical training in a safe environment. Many nursing homes and older adult facilities offer residents physical therapy as part of the daily exercise options. Many older adults are opposed to exercises that involve physical activity. VR and AR applications can represent novel systems through which they modify their negative perceptions of exercise and learn to enjoy it. [PERSON] et al. [41] described that some form of fun factors must be included in exercise to motivate people to engage in physical activity. They performed a study that involved placing exercise bikes in front of large screens. As the users pedaled, the screens displayed virtual landscapes that the participants rode through at speeds that were aligned with their output on the bike.