Development of hip protectors for snowboarding utilizing 3D modeling and 3D printing

The purpose of this study was to develop a highly comfortable 3D male hip protector using 3D modeling and printing technologies. The hip protector pads and patterns were devised using 3D human body shapes, and three types of pads were chosen in consideration of snowboarding motions. The three types of pads were as follows: first, the original type with no hole; second, an inner open type with an incision on the inside; and third, an outer open type, with an incision on the outside. Another variable of the protective pads was the material: 3D printed thermoplastic polyurethane (TPU) pad + ethylene-vinyl acetate (EVA) foam or only EVA foam. Six types of pad prototypes were 3D printed and evaluated for subjective wearing comfort. Subjective comfort, fit, activity comfort, and shock absorption were evaluated on an 11-point Likert scale. The study results showed that protectors printed using TPU material were not different from the results of 3D modeling. The evaluation results revealed that comfort, fit, and motion comfort were all negatively evaluated by subjects when wearing the original pad. While fit, comfort, and motion comfort were all positively evaluated by subjects when wearing the outer open-type pad, and comfort and motion comfort were positively evaluated by subjects when wearing the inner open-type pad. With respect to materials, pads made with the 3D printing (TPU) and EVA foam combination provided the best results in terms of overall comfort, buttocks comfort, and activity comfort.