# Conceptual Design of an Extended Reality Exercise Game for the Elderly
## 2 Background and Related Work
### Elderly Physical Health and VR Exercise Games  
Within XR exercise games for the elderly, the previous work, Elderly SLR [13], narrowed the scope of the study and reviewed relevant work over the past 10 years. Across the 14 included articles, similar results were found for the other 3 previously mentioned studies (the SLR [10], Healthcare Survey [11], and Public Survey [12]) that VR games have the largest share. Moreover, in line with the WHO recommendation, most tasks were transportation (cycling) and sports (ball games). In addition, from the previous study [13], we could see seniors' positive attitudes toward XR techniques and XR exercise games for physical health, and evidence of the positive health effects of using such XR games. Unlike applications for other user age groups (included papers in the SLR [10], and mentioned XR applications in the Healthcare Survey [11] and Public Survey [12]) ), the 14 included papers (in the Elderly SLR [13]) considered attributes and characteristics when designing XR exercise games for the elderly and reflected in the use of posture, enhancing motivation, and interaction methods. The details are shown as follows. Teamwork and allowing multi-users affected not only mental health, but also increased socialization and thus became factors that facilitated user usage. The interviewees' comments on interaction and control methods were as simple and straightforward as possible, with high requirements on ease and confidence in use, acceptability, and learnability. Fewer devices and simplified interfaces were mentioned as well. Moreover, the interaction of physical and mental health was a factor to consider. Sitting and lower body activities were the preferred posture and activity body parts for such software [13]. However, [PERSON] and [PERSON] pointed out even if lower-body-movement games are more effective than upper-body movement, whole-body movement is the most effective [28]. Based on the above results, the specific design requirement keywords of a VR exercise game for the elderly can be summarized: whole-body activity, transportation or sports activity, simple device and operation, double tasks for physical and mental health, and including social interaction. About game techniques in such included papers, the previous SLR [10] obtained the following results: gamification in XR healthcare games was mainly used to increase the motivation to use the game for the fun and entertainment of playing, thereby prolonging the use duration and expanding the use frequency. The most used game elements of the included papers were points (the rewards players receive for completing specific tasks [29], and the digitally measuring player behaviour in the game [29]), meaningful stories, and avatars. The first two could help encourage usage by reflecting the user's performance in the game in real time and reducing boredom. These results could support the feasibility and necessity of gamification in XR healthcare applications and have a reference value for selecting game elements and types (such as shooting, action, adventure, and role playing). Using the included papers in the SLR (only papers targeting the elderly physical health) [10] and SLR for the elderly [13], we tried to analyse the exercise activities, game tasks, and supporting theories of VR physical training applications for the elderly. From Table 1, the analysis results show that physical training commonly uses existing sports as the exercise activities (such as cycling and ball games). Except for physical training, many studies have double tasks (including mental training). Daily life activities (shopping/searching/cooking), orientation, interaction with objects or animals, and travelling were the main game tasks. The included papers have evidence to support applying VR and game techniques for exercise for seniors.