# Influence of Induced Environment Oscillations on Limits of Stability in Healthy Adults
## 4 Discussion  
Virtual reality is becoming an increasingly extensively used technique for enhancing rehabilitation, performing research on human motorics, and diagnosing physical dysfunctionalities [10; 11; 12; 13]. Although the number of reports stating the successful use of said technology for the purpose of making the physiotherapy process more efficient, increasing patients' engagement in exercises, or even allowing them to train in order to keep progressing through physiotherapy at home is increasing, VR does not always guarantee an increase in achieved results. From an analysis of our results, we can conclude that the introduction of VR to measurements of LOS does not allow patients to achieve better results and increase their capabilities of moving their COP over limits that are achieved in conditions of real-life environments with eyes open, best resembling everyday life conditions. As reported in [14], LOS measurements are a viable method of assessing a healthy adult's functional stability; the authors also proposed methods of measuring and analyzing limits of stability. We aimed to find if the introduction of scenery oscillations or of VR itself affects one's LOS, and therefore gives reasons for the initial thinking that it can be used for therapeutic means. To the authors' best knowledge, no other publication about analyzing limits of stability has been published, nor publications analyzing the COP for each foot separately. Revised were PubMed and Infona publication databases, and no records on research performed in similar conditions were found prior to conducted research. We also looked for asymmetry in the use of the lower limbs when reaching LOS. The beginning of movement point was chosen for our calculations in order to avoid drift of baseline, as during times of rest between leans, the mean position of the COP was usually not the same as it was at the beginning of the measurement until first sound cue signalizing the start of leaning was played; therefore, we believed that participants would lean by a comparable amount in each leaning phase from the point taken as the beginning of leaning to the self-believed limit. We also made attempts to recreate the approach with regression lines presented in [14] for analysis, but swaying induced by VR scenery oscillations and relatively short times of keeping the maximum leaned position resulted in heavily angled regression lines, causing a drastic shift in the point of crossing of said lines, shortening the number of samples that could be taken into account for the analysis of the lean-keeping phase. Out of 420 compared combinations of medians, only 4 gave positive results (meaning the medians were statistically different). The performed statistical tests were checked for their power value, and the result was always more than or very close to 0.8. This proves that the performed analyses returned statistically significant results. In our research, it turned out that 0.2 Hz oscillations affect the velocity at which maximum backward lean is reached, slowing the process of leaning and also lowering the interquartile range, presenting greater repeatability of results. These results were registered for both feet COP separately as well as for total COP and always included trials with 0.2 Hz scenery oscillations. No other oscillating scenery trial displayed a statistically significant difference, including leaning