# Recurrence Quantification Analysis as a Form of Postural Control Assessment: A Systematic Review
## 3 Results
### Sport/Influence of Motion/Impact of Visual Stimuli  
The highest number--twelve papers--were in the sport/influence of motion/impact of visual stimuli group. A total of 661 participants were analyzed. Their mean age ranged from 20 [18; 49] to 79 \(\pm\) 2.8 years [61]. Their mean body weight and height values ranged from 66.4 \(\pm\) 12.2 kg [63] to 78 \(\pm\) 15 kg [20] and from 160.6 \(\pm\) 5.35 cm [64] to 176 \(\pm\) 7 cm [61], respectively. Six types of force platforms measured CoP fluctuations with different sampling rates. In two papers, authors used Techno Concept platforms (40 Hz) [43; 62]. Three studies [63; 64; 67] used Medicapteur force plates (40 Hz). Moreover, in three works [48; 65; 68], Bertec platforms (1000 Hz) were used. In a single study, data were sampled at 2000 Hz using a Kistler platform [20] and at 1000 Hz [61] using an AMTI force platform. The remaining papers sampled data at 100 Hz and used Smart Balance [49] and Bertec [18] force plates. In this group, a very large discrepancy in measurement times was noted. The traditional 30 s trials with eyes open and closed were performed in one study [18]. [PERSON] et al. [61] performed the same long trial, however, only with eyes open and while standing in semi-tandem. [PERSON] et al. [68] took into account only standing on two legs with eyes open. This group was dominated by tests lasting 51.2 s, which can be found in 5 papers [62; 63; 64; 67; 43; 67]. [PERSON] et al. [20] performed tests lasting 135 s; [PERSON] et al. [48] and [PERSON] et al. [65]--60 s. In [PERSON] and [PERSON]'s [49] paper, there were trials lasting only 20 s. Only in five papers [63; 64; 65; 67], the authors indicated what tool they used to calculate RQA measures. The Cross Recurrence Plot Toolbox by [PERSON] et al. [6] was used four times. The Recurrence Quantification Toolbox for MATLAB of [PERSON] et al. [66] was used by [PERSON] et al. [65]. To perform RQA analysis, time delay, embedding dimension, and threshold were used. [PERSON] et al. [67] and [PERSON] et al. [61] did not provide their values. In five works [48; 63; 64; 65; 68], the embedding dimension was 8. In the remaining works, it was 5 [20], 9 [49], 10 [18], 11 [18], or 12 [43; 62]. It is worth noting that there were significant discrepancies in both the time lag values and the recurrence thresholds. The time delay ranged from tau = 50 ms (corresponding to 2 samples) [43; 62] to tau = 180 ms [20]. The radius for recurrence was 2-3% [43; 62], 11% [49], 20% [18], 24% [18], and 25% [64] of the mean distance between data points, among others. Table 5 includes RQA parameter values specific for the sport/influence of motion/impact of visual stimuli group. In four papers [48; 49; 65; 68], the authors did not provide RQA parameter values. In four [63; 64; 20; 67] of the remaining eight papers, the authors did not provide %REC values. [PERSON] et al. [18] showed that %REC was higher for balance tests in runners relative to the dancer's group. In both groups, %REC was higher for trials with visual control included for AP direction. [PERSON] et al. [43] showed that %REC for open-eye trials was higher in the dancer group relative to the fall prevention group, not dependent on the direction or recurrence radius. [PERSON] et al. [61] showed that %REC was higher in the elderly group relative to the young, mainly for the AP direction when standing in semi-tandem. [PERSON] et al. [62] showed that dancers in most trials had higher %REC values relative to those recorded for the control group. %DET was in each of the eight papers. [PERSON] et al. [18] showed that %DET values were higher for standing with eyes closed in both study groups. However, the result of [PERSON] et al. [63] was the opposite. In [PERSON] et al. 's [43] paper, %DET maintained the trend set by %REC. [PERSON] et al. [61] showed that %DET had higher values in the young group. [PERSON] et al. [20] showed that %DET was lowest in the young group and highest in the group of non-fallers. ENT values were mentioned in only three papers [18; 61; 64]. [PERSON] et al.