## 3 Model Development and Validation
### Data Analysis
There are significant differences in contact pressure for different backrest inclination angles, where 120\({}^{\circ}\) inclination (13.29 \(\pm\) 0.29 kPa) \(>\) 100\({}^{\circ}\) inclination (13.13 \(\pm\) 0.18 kPa) \(>\) 110\({}^{\circ}\) inclination (13.01 \(\pm\) 0.14 kPa). Usually, reducing the discomfort caused by contact pressure can improve the comfort during human contact with the support surface, resulting in less irritation being felt by the human body. As shown in Table 4, a post hoc two-by-two comparison of the three backrest inclination angles at 63 cm showed significant differences in back-contact pressure and hip-contact pressure at 95% confidence intervals for each of the two different angles. Hip strength refers to the strength of the force or pressure exerted in the hip region of the human body. For buttock strength, the greatest strength was found at an inclination angle of 100\({}^{\circ}\) at 977.39 \(\pm\) 20.96 kPa, followed by 934.55 \(\pm\) 17.67 kPa at an inclination angle of 110\({}^{\circ}\) and 902.32 \(\pm\) 18.01 kPa at an inclination angle of 120\({}^{\circ}\). Usually, a smaller buttock strength helps to reduce local discomfort and avoid pressure concentration on the skin and tissues. As shown in Table 4, a post hoc two-by-two comparison of the three backrest inclination angles at 63 cm showed significant differences in hip strength at 95% confidence intervals for each of the two different angles. The significance of the pressure distribution when the seat and pedal pitch are 63 cm and a post-hoc two-by-two comparison are shown in Tables 3 and 4. As shown in Table 5, the peak back-object pressure was the highest at 36.66 \(\pm\) 1.89 kPa at a tilt angle of 100\({}^{\circ}\), followed by 36.17 \(\pm\) 1.93 kPa at a tilt angle of 110\({}^{\circ}\) and 31.23 \(\pm\) 1.48 kPa at a tilt angle of 120\({}^{\circ}\) for a seat and footrest pitch of 68 cm. As shown in Table 6, for the three backrest tilt angles at 68 cm pitch, a post hoc two-by-two comparison was conducted, and the peak back-object pressures for each of the two different angles were significantly different at the 95% confidence interval. As shown in Table 5, the peak back-contact pressure at a seat-to-footrest pitch of 68 cm was the highest at an inclination angle of 100\({}^{\circ}\), at 38.82 \(\pm\) 2.01 kPa; followed by 37.75 \(\pm\) 1.52 kPa at an inclination angle of 110\({}^{\circ}\); and the lowest at an inclination angle of 120\({}^{\circ}\), at 32.31 \(\pm\) 1.52 kPa. As shown in Table 6, the peak back-contact pressure for a post hoc two-by-two comparison of the three backrest inclination angles at 68 cm spacing showed that the peak back-contact pressure at each of the two different angles was significantly different at the 95% confidence interval. At a distance of 68 cm, the back-contact area was the largest at 120\({}^{\circ}\) backrest inclination, at 479.41 \(\pm\) 13.29 cm\({}^{2}\); the smallest at 100\({}^{\circ}\) back-contact area, 392.11 \(\pm\) 8.76 cm\({}^{2}\); and in the middle at 110\({}^{\circ}\) inclination, at 410.83 \(\pm\) 11.04 cm\({}^{2}\). Hip contact pressure is also the opposite of the back-contact pressure and is greatest when the tilt angle is 110\({}^{\circ}\) at 745.07 \(\pm\) 10.23 cm\({}^{2}\), followed by 730.21 \(\pm\) 6.32 cm\({}^{2}\) at 110\({}^{\circ}\) and 679.49 \(\pm\) 8.32 cm\({}^{2}\) at 120\({}^{\circ}\). When the same seat material is used, a large contact area represents a better experience being measured. As above, for the actual driving conditions, a larger reline angle has an impact on the driving view, resulting in a restricted viewable area, so a larger reline angle is usually unsuitable for driving conditions. As shown in Table 6, a post hoc two-by-two comparison of the three reline angles at 68 cm spacing showed that the back-contact area at each of the two different angles was significantly different at the 95% confidence interval.