1.The H-point refers to the rotational center between the human thigh and torso. In a three-dimensional H-point device, it refers to the connection center between the seat cushion and the seatback. The H-point position of a car seat has a significant impact on determining key reference points and spatial dimensions within the vehicle, and it directly affects the determination of the R-point as well as the safety and comfort of vehicle seating. In automotive crash tests, the seatback and seat cushion assemblies of the crash test dummy used in automotive collision simulation analysis are also hinged at the H-point, making the correct determination of the seat H-point position a prerequisite for properly installing the dummy. Therefore, being able to more accurately and conveniently mark the H-point position of a car seat, and correctly use the three-dimensional H-point device (HPM-I), is particularly important. 

2. The HPM-I model consists of seven parts: the seatback assembly, seat cushion assembly, lower legs, thigh rods, shoe assembly, head space device, and weights (back weight, pelvis weight, thigh weight, lower leg weight).