## 4 Discussion  
This study was performed aiming to provide the relevant information to contribute to para athletics' performance improvement by identifying a change in the disciplines of the Paralympic Games (2004-2020) in the para athletic track events that represented para sports, and by analyzing game record differences and athletic performance trends by the level (podium and final groups) of top-ranking men and women athletes (No, 1-No, 8) who participated in track events. Discussions according to the study results are as follows: In the difference verification of game records by class and discipline, differences were revealed in 100 m (T11, T36), 400 m (T53, T54), 800 m (T53, T54), 1500 m (T11, T13, T46, T54), and 5000 m (T54) of the podium and final groups. This indicates that athletic performance level is persistently improving in para athletics. In each impairment type, namely, visual  
Figure 2: Women’s Division Record Change Trend in the Track Events of the Paralympic Games. impairment (T11, T13), wheelchair racing (T53, T54), cerebral palsy (T36), and amputation impairment (T46) types, game records were evenly improved. The athletic performance improvement seems to derive from a phenomenon where athletes participated in the remaining events from the disappeared events due to the reduction in disciplines by IPC, so competitiveness was consolidated by a concentration of athletes. It was judged that the discipline reduction and integration process from the Athens 2004 Paralympic Games to the Tokyo 2020 Paralympic Games affected it [1; 2]. In wheelchair class, record change was larger in short rather than long distances, and the same result was found in previous studies [25]. This is also due to the increase in athletes between their teens and 30 s in the Paralympic Games, with young athletes' participation and the equipment technology development appearing to affect records [26; 27; 28]. Refs. [28; 29] reported that athletic performance increased with the highest ratio in the 400 m of T54 in the wheelchair class until the Rio 2016 Paralympic Games. In wheelchair racing events a sports' scientific approach, including minimization of aerodynamic drag in various areas to improve athletic performance, led to record improvement [30]. However, as shown in Figure 1, in T54 the 1500 m of long distance in the Tokyo 2020 Paralympic Games a record of 2 min and 50 s was revealed, which can be interpreted that the mean speed of the athletes' race operation is extremely fast. As shown in Table 1, records showed a slight deterioration in some classes and disciplines, namely in 100 m (T52, T54) and 800 m in the London 2012 Paralympic Games and 800 m (T53) in Rio 2016. There was a difference in standard deviance between the podium and final groups. This means that differences in the podium group were not significant but big in the final group, so there seemed to be differences in athletic performance. In differences in the verification of game records by class and discipline in women's events, differences were found in the podium and final groups in 100 m (T13, T37), 200 m (T12), 400 m (T53), 800 m (T54), 1500 m (T54), and 5000 (T54). In 100 m (T11, T12, T36, T53), 200 m (T11), and 800 m (T53), significant differences were revealed in only the final group. In the case of visual impairment (VI), the athletic performance of a guide runner may be affected by the other runners' athletic performance. Generally, during runners' participation in an event, better results seem to be produced if a male runner with excellent athletic performance was running as a guide runner, compared to a visually impaired runner leading the running. In a record competition game, if a partner's athletic performance is excellent the other runner can more easily maintain a higher pace than one's own, along with a trend to follow the partner [31; 32]. Athletes are participating in a record competition game train with a pacemaker in training. An opportunity can be assured to raise one's limit if the pacemaker leads faster than one's own in a short section.