Introduction: In order to develop a good hip protector to prevent in the elderly hip fracture as a result of a fall, we studied the buffer characteristics of sponges and air cushions. Methods: The buffer rate of material was defined, and the absorption ability of the material to instantaneous impact was evaluated. An experimental device was developed and used to measure the buffer rates of sponges and leak-allowed air cushions with orifice(s). Results: According to the experimental results, the buffer rate largely depended on the hardness of the sponge materials, and on the total area of the orifice(s) for the leak-allowed air cushions. Compared with the sponge with correct hardness and thickness, the buffer characteristic of the air cushion seems slightly inferior. Conclusions: Nevertheless, the air cushion's overall performance, including the better buffer rate, ultra-lightness, flexibility, and low cost, makes it a potentially useful material for hip protectors and other sport protectors.