## 2 Materials and Methods
### Experimental Subjects  
Twelve graduate students (6 males and 6 females) of similar age and in good physical and mental health were recruited as participants for this experiment, with an average age of 26 \(\pm\) 2 years, average weight of 68.1 \(\pm\) 12 kg, and average height of 171 \(\pm\) 13 mm. Before the experiment, participants were asked to stop vigorous exercise for 48 h and confirm that they were free from any skin diseases, limb injuries, or muscle impairments. Participants volunteered for the experiment and retained the right to withdraw at any time without providing an explanation. Table 1 lists the gender, age, height, and weight of all participants. Before the start of the experiments, all participants were asked to sign an informed consent form. The experimental procedures, specifications, and risks were comprehensively explained to each participant. The experiment was approved by Xi'an Jiaotong University City College. According to [PERSON]'s (1992) guidelines, for a medium effect size (effect size = 0.5), achieving 80% statistical power (power = 0.80) at a common significance level (alpha = 0.05) requires a sample size of approximately 12 to 15 participants. Our preliminary power analysis indicated that, with an effect size of 0.8, a sample size of 12 is sufficient to detect significant differences. Additionally, graduate students typically have similar ages, consistent health conditions, and comparable lifestyle habits and activity patterns, including frequent sedentary behavior. This homogeneity helps reduce variability caused by individual differences, making the experimental results more comparable and controllable. However, we also recognize that a sample size of 12 may have limitations and may not fully represent the entire graduate student population. This is a limitation of our study. To enhance the reliability of our conclusions, we applied additional statistical tests in our data analysis. First, we used one-way analysis of variance (ANOVA) to compare the significant differences in pressure distribution across different tilt angles. The results indicate that different tilt angles have a significant impact on pressure distribution (\(p<0.05\)). Subsequently, we performed post hoc tests (such as the Tukey HSD test) to determine which specific angles showed significant differences. Additionally, we employed multiple regression analysis to evaluate the combined effects of body weight and tilt angle on pressure distribution and comfort evaluation. The analysis revealed that both body weight and tilt angle significantly affect pressure distribution (\(p<0.05\)) and that there is a significant interaction between the two. These results further validate the importance of individual body weight and tilt angle in influencing comfort assessments. Individuals have different body weights and sizes, resulting in differences in the contact area and pressure distribution between the body and the seat, leading to different levels of individual comfort. For example, individuals with higher body weight may \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Gender** & **Age** & **Height (mm)** & **Weight (kg)** \\ \hline P1 & male & 26 & 175 & 65.0 \\ P2 & female & 27 & 163 & 60.2 \\ P3 & male & 26 & 177 & 79.6 \\ P4 & male & 28 & 182 & 75.8 \\ P5 & female & 26 & 173 & 51.5 \\ P6 & female & 27 & 165 & 65.3 \\ P7 & male & 25 & 184 & 75.5 \\ P8 & male & 24 & 181 & 80.2 \\ P9 & male & 26 & 173 & 72.5 \\ P10 & female & 24 & 160 & 63.0 \\ P11 & female & 27 & 161 & 58.1 \\ P12 & female & 25 & 160 & 70.2 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Demographic information of participants. experience greater pressure at larger seat inclination angles, reducing their comfort perception. Conversely, individuals with lower body weight may experience less pressure under the same conditions, resulting in different comfort evaluations for the same inclination angles. Therefore, we selected participants with similar heights but varying body weights to capture a broader range of responses.