# Reaction Time and Postural Control Under Dual-Task Conditions in Brazilian Jiu-Jitsu Athletes
## 4 Discussion  
This study aimed to assess whether Brazilian Jiu-Jitsu athletes exhibit faster reaction times in specific positions compared to untrained control subjects across various postural trials. Additionally, this study sought to evaluate whether Brazilian Jiu-Jitsu athletes demonstrate more complex postural control than control subjects during tasks that require focus and attention. Reaction time, as noted by [PERSON] et al. [42], is a critical parameter in sports, reflecting an individual's ability to respond quickly to external stimuli. In combat sports like Brazilian Jiu-Jitsu, reaction time is particularly vital, as athletes must respond instantly to dynamic and unpredictable situations, such as countering an opponent's movements or transitioning between techniques. Effective reaction times can determine success in both offensive and defensive scenarios, making it an essential skill for high-level performance. In this study, Brazilian Jiu-Jitsu athletes demonstrated significantly faster reaction times in both sitting and standing positions when compared to the control group. Notably, the athletes also achieved significantly higher numbers of light-off events in the sitting position, indicating enhanced focus and response efficiency in this posture. Here, the sitting position appears to be particularly effective in differentiating athletes from non-athletes, likely due to the specific training exercises in Brazilian Jiu-Jitsu that involve engaging core stability; spatial awareness; and rapid decision-making while seated, such as defending guard positions or transitioning into attacks [43,44]. According to [PERSON] et al. [43], Brazilian Jiu-Jitsu is a martial art that not only requires strength and flexibility but also places a significant emphasis on balance. The ability to maintain and adjust one's balance is crucial for executing effective offensive and defensive techniques [45]. Research consistently supports the idea that long-term training, particularly exercises that challenge and disrupt balance, has a positive impact on improving postural control [46,47]. Such training helps individuals develop a heightened sense of balance, enabling them to respond more effectively to dynamic situations. This study utilized both linear and nonlinear parameters to assess postural control, focusing on the complexity of postural control and the regularity of the CoP signal during four tasks: standing on both feet and one leg with eyes open, as well as standing on both feet and one leg while tracking a chaotically moving point on a screen. The linear parameter (CoP path length) did not significantly differentiate the groups. The control group consistently showed longer CoP paths in each task, reflecting greater balance fluctuations and reduced stability compared to Brazilian Jiu-Jitsu athletes. Similar findings were reported by [PERSON]'s study [34], who observed no differences in quiet standing between elite Jiu-Jitsu athletes and control subjects. In contrast, nonlinear measures provided more detailed and informative insights. Specifically, SampEn_ML_2 eo was higher in the control group compared to in Brazilian Jiu-Jitsu athletes, suggesting that the control group exhibited a more irregular mediolateral CoP signal when standing on both feet and with eyes open. This irregularity may indicate less consistent postural strategies or a lack of refined balance control, which is often seen in untrained individuals. In contrast, the lower SampEn values in Brazilian Jiu-Jitsu athletes suggest more regular and efficient postural control in this task, likely reflecting the effects of their training on balance stability. For LyE_ML_1 eo, Brazilian Jiu-Jitsu athletes displayed higher values compared to the control group, indicating greater divergence in the mediolateral CoP trajectory during one-legged standing with eyes open. Higher Lyapunov Exponent values are associated with greater adaptability and complexity in the postural control system, which is advantageous in dynamic environments.