# Design and Validation of Rule-Based Expert System by Using Kinect V2 for Real-Time Athlete Support
## 3 Results and Discussion
### The Effect of the System on Physical and Cognitive Development  
In order to examine the effect of the system on physical and cognitive development, participants were asked to perform LR and DSP trainings (4 sets, 8-12 reps, and 70%-90% load) using the system for four weeks. Glenohumeral joints (right and left shoulder) and spine displacement values of the participants were recorded via the system during the trainings. The recorded data are shown in Figure 9 as the amount of position change in the joints (cm) by type of training, participant number, and joint type. The data obtained in Figure 9 are presented in Appendix A as Table A1. When Figure 9--which is showing the average weekly displacement of glenohumeral joints and spine affected by DSP and LR training--was examined, it was observed that users started to do their movements using only the related muscles without using momentum, and minimized the risk of injury in this process as stated in [85]. Furthermore, in these data, an average enhancement of 54.84% \(\pm\) 12.72% in DSP training and 58.08% \(\pm\) 11.32% in LR training is observed. This indicates that each participant has performed their training more stably at the end of the system usage process, as stated in [92]. A detailed analysis of these recovery rates is shown in Table 8.  
The data shown in Figure 9 were analyzed using SPSS via the paired \(t\)-test according to the significance criterion \(p<0.05\), and the results are presented in Table 9. In this table, the results of the paired \(t\)-test analysis of the weekly joint displacement are shown in pairs (1-2, 1-3, 1-4) according to the training of the participants, as available. In addition, d values are added to the last column of the table. Figure 9: Joint displacement of participants during a four-week training period. DSP: dumbbell shoulder press; LR: lateral raise; GJLweek1: glenohumeral left joint week 1; GJRweek1: glenohumeral right joint week 1; Spweek1: spine week 1; GJRweek2: glenohumeral right joint week 2; Spweek2: spline week 2; GJLweek2: glenohumeral left joint week 2; GJRweek3: glenohumeral right joint week 3; Spweek3: spine week 3; GJLweek3: glenohumeral left joint week 3; GJRweek4: glenohumeral right joint week 4; Spweek4: spine week 4; GJLweek4: glenohumeral left joint week 4. (a) left glenohumeral joint displacement for DSP; (b) right glenohumeral joint displacement for DSP; (c) spine displacement for DSP; (d) left glenohumeral joint displacement for LR; (e) right glenohumeral joint displacement for LR; (f) spine displacement for LR. The results of the analysis indicate a significant change in physical ability (\(p<0.005\)) in DSP (Pair 1-9) and LR (Pair 10-18) training using the system from the first week. This change continues throughout the process. When the results were examined in terms of effect size, weak and medium effects were observed in the pair 1, pair 4, and pair 7 data in the comparison of the first and second weeks of DSP training, whereas large and strong effects were observed in the other pairs starting from the second week. In LR training, only medium and large effects were observed in pair 10, pair 16, and pair 17, while the remaining pairs had strong effects. These results support a significant change in physical ability according to the \(p\) value. To examine the cognitive development during the training process, an independent \(t\)-test was applied to the left glenohumeral joint, right glenohumeral joint, and spine data of the 1 st and 4 th weeks. The results obtained from this analysis are shown in Table 10 with d values. Table 10 is examined primarily according to the Sig. value ([PERSON]'s test). If this value is less than 0.05, the variances are not homogeneous. In this case, the equal variances not assumed line is used. However, if the Sig. value is greater than 0.05, it is decided that the variances are homogeneous. The \(p\) and d values (Sig. (2-tailed)) used in these cases are shown in the table as underlined.