# A Virtual Reality-Based Simulation Tool for Assessing the Risk of Falls in Older Adults
## 2 Related Work
VR is an ideal platform for cognitive-motor interference because it offers physical exercise, joy, and cognitive functions in one platform, increasing the intervention's ecological validity, safety, and acceptance. The literature highlighted commercial VR-based exergames for multiple physical activities, such as balance and strength training for older adults. Thus, the efficacy and feasibility of VR technology have been acknowledged to minimize the risks of falls [40; 41; 42]. [PERSON] et al. [43] created a VR simulator to evaluate the risk of falls for construction workers. The VR system comprised three trackers, a VR headset, and a virtual environment. The inverse kinematic method was used for the body-joint simulations to create the virtual leg movements. The study showed that the VR simulator performed better than the traditional VR systems to asses upper-limb stability during gait movements [43]. Another study investigated the effect of multiple VR-based visual stimuli on postural control while standing in an upright posture. The participants' postural stability was quantified by measuring the center of pressure (COP) in a VR environment. The authors created the virtual simulation of the rotary optokinetic drum and observed that visual stimuli invoked by the rotary optokinetic drum may enhance the instability more than the stance with the eyes closed [44]. [PERSON] et al. examined the impact of delayed visual feedback and cognitive performance on postural control in healthy young and elderly populations. The participants were asked to position their COP (upright posture with eyes open) in a fixed target as precisely as possible with the visual and delayed-visual feedback of their COP position. They also performed arithmetic tasks (cognitive dual tasks). An increase in postural sway was observed in older adults with delayed visual feedback, which indicates that older adults rely more on vision to control their posture [45]. One study assessed the validity and reliability of the data from a Wii balance board (WBB) against a force platform (FP) in older adults with type 2 diabetes mellitus. The regression model showed that the WBB was able to describe most of the changes in COP sway of the force platform between 42 and 72% for all test cases. The authors suggest that WBB is a valid and reliable tool for quantifying the COP excursion [46]. Another study created a VR-based tool to assess the risks of falls. A head-mounted display (HMD) was used along with motion sensors to record kinematic data during the tests. The results indicated that the participants who were at high risk of falls took a longer execution time for interventions and a number of steps [47]. [PERSON] introduced a VR tool to assess the risk of falls in the elderly. The author implemented the choice stepping reaction time task (CSRT) and used an HTC Vive headset (VR headset), suggesting that the highly immersive VR tool can concentrate more on cognitive and motor tasks instead of the technology being used [48]. Similarly, an Oculus Rift headset was used in another study to assess dynamic balance through head mobility. A virtual park scene was created where participants had to ask to save their heads from approaching the balls. The objective of the task was to stimulate the vestibular function to quantify head movements and assess dynamic balance. The results indicated significant between-group differences in head paths, head accelerations, and peak frequencies. However, no significant differences were found in the postural sway parameters [49]. Another study used non-immersive VR and treadmill training to improve cognition and body movements and identified fewer incidents of falls when compared to treadmill training without VR [50]. Some studies showed the efficiency of novel tech-based intervention programs in improving balance [51,52] and locomotion in older adults [50,53].