# How Long Does It Take to Stop? Are Children Able to Stop on Demand?
## 5 Discussion  
During the course of the tests, we carefully considered the boundary conditions of the test setup and determined that the length of the test course differs from what is stated in the literature. While [PERSON] and [PERSON]'s complete test course [25; 26; 42] was 15 m long, it is assumed that the initial five meters constituted the acceleration phase. [PERSON] and [PERSON] [27] (cited in [PERSON] and [PERSON] [30]) employed a test set-up that encompassed the entire course length of 10 m. However, the length of the acceleration phase was not specified. [PERSON] et al. [29] (also cited in [PERSON] and [PERSON] [30]) used a course length of 10 m to determine only steady-state speed, indicating that the participants did not accelerate from a standstill. The recorded steady-state speeds of the children in different age groups are comparable with findings in the literature. However, they are lower than those reported by some previous studies (see [PERSON] and [PERSON] [25; 26; 42], [PERSON], and [PERSON] [27] (cited in [PERSON] and [PERSON] [30]), [PERSON] and [PERSON] [28] (cited in [PERSON] and [PERSON] [25; 26]). These differences may be attributable to variations in the test configuration. It is expected that the children will attain a constant speed subsequent to the second light beam, following an acceleration phase of 1.3 m. It is important to note that if the children do not attain a constant speed immediately after this brief acceleration phase, they will persist in accelerating, despite the assumption of a steady-state speed. It is assumed that a steady-state speed is maintained between the second and third light beams, but there is still acceleration. In the context of the walking test configuration, it has been observed that a steady-state speed is maintained between the second and third light beams. However, the acceleration phase of the running tests is characterized by a prolonged duration, with steady-state speed being attained at a subsequent stage. It is important to acknowledge the potential underestimation of the steady-state speed attained after the second light beam, which may be more than the values reported in the extant literature. As shown in Figure 6, the calculation of steady-state speed based on the distance and time between the second and third light beams results in a speed of 7.2 km/h. During the acceleration phase, a lower speed can be calculated based on the distance and time between light beams. In this particular example, the steady-state speed between the first and second light beams is calculated to be 6 km/h. Research has demonstrated that older children, including both girls and boys, demonstrate higher speeds, a finding that aligns with existing literature on the subject. Despite the finding that steady-state speed is lower than the values reported in the extant literature, this discrepancy does not contradict the observed tendency. A number of studies have proposed a categorization based on specific age groups and gender, as evidenced by the works of [PERSON] and [PERSON] [25; 26; 42], [PERSON] and [PERSON] [27] (cited in [PERSON] and [PERSON] [25; 26]), and [PERSON] and [PERSON] [28] (cited in [PERSON] and [PERSON] [25; 26]). The results show that older children attain higher speeds. According to [PERSON] and [PERSON] [25; 26; 42] as well as [PERSON] and [PERSON] [27] (cited in [PERSON] and [PERSON] [25; 26]), boys tend to exhibit higher levels of speed in comparison to girls. Nevertheless, this observation was not substantiated in the present study. A paucity of studies exists that examine the stopping distance or deceleration of children according to their age group. However, the extant literature on deceleration behavior primarily focuses on adults and their body postures immediately before collision [43; 44; 45; 46]. It is important to note that these postures can exert a substantial influence on the patterns and severity of injuries.