## 4 Discussion  
In this study, we aimed to investigate the impact of a VR-based training program on healthy older adults' balance ability. VR participants reduced the combined AP and ML COP parameter, total excursion (TE), pre- compared to post-training for the double-leg stance. A reduction of this COP parameter was interpreted as the VR group decreasing the total length of the COP, and thus, they were able to maintain better balance for this test condition. Improved balance was consistent with previous studies. Other studies reported improvements in balance after exercise training with the use of a VR device [11; 14; 15; 16; 21; 28; 29]. In a study by [PERSON] et al., results after post-training with a VR system showed improvements in balance parameters, which included AE and maximum sway [17]. Meanwhile, another study only analyzed tandem stance amongst older adults before and after VR-based exercise training [16]. Both studies reported an improvement in standing balance post-VR exercise training compared to pre-training. A review study also researched the effectiveness of immersive VR training on balance, gait, and mobility, reporting that VR training can improve balance in older adults [15; 20; 21]. However, studies have reported inconsistent results (either improvement or no improvement) between control and VR participants post-exercise training. One study reported no significant changes in balance ability pre- to post-exercise training for both the control and VR groups [30]. Another study reported similar changes in balance post-exercise training for both the VR and control groups, signifying no method was superior to the other. Additionally, other studies have commonly only reported on the TUG or the Falls Efficacy Scale as assessment measures; however, these do not identify the details of an individual's postural movements that may lead to an increase in fall risk [15; 20; 21]. Therefore, our study provides more concrete metrics (COP parameters) to capture and analyze an individual's balance improvement. For the control participants, we also observed insignificant changes in the RMS AP, MAXD AP and ML, and in TE. The control group had a worsening (increase) of the area ellipse (AE) for the double-leg stance. While this study did not see significant improvement  
Figure 6: 95% Area ellipse (top). (**a**) double-leg, (**b**) tandem, and (**c**) single-leg stance and total excursion (bottom) (**d**) double-leg, (**e**) tandem, and (**f**) single-leg stance. Results for VR group and control group pre-training (open icons) and post-training (filled icons) with standard error bars shown. in balance ability from the control group, a related study reported that the control group had enhanced balance and postural control after a 6-week exercise training course [15]. Further, one important factor to note is, on average, the control group had poorer performance compared to the VR group pre-training, which may have led to mixed differences post-training. Overall, our study's analysis of the COP parameters post-training could advise the progression of targeted interventions specific to areas needing balance improvement in older adults. Additionally, recognizing the success of exercise training on postural stability and balance ability allows clinical personnel to tailor rehabilitation strategies, specifically for older adults who may be at risk for falls. Our results showed variability in postural stability outcomes. Lastly, this study contributes to the developing list of research on VR use, exercise training, and balance performance. To continue to improve future research, comprehending these aspects is critical to adapting intervention plans and improving outcomes aimed to improve balance and decrease the risk of falls in older adults. The use of VR training may provide an added benefit outside of the traditional exercise regimen, such as improved incentive and enjoyment leading to increased compliance with prescribed exercise training among older adults.