Japanese bed frames are on the floor because traditionally, Japanese people slept for more than 1000 years. Japanese people believe that sleeping on the floor helps to relax muscles and promote spine alignment. Furthermore, Japanese apartments are smaller; thus, they need beds folded and stored in the closet to create extra space. Most Japanese apartments do not have a bedroom. As a result, people use the available space in the day as a living room and a bedroom at night. They use soft mats known as tatami mats woven from rice straw instead of carpets. Furthermore, their traditional floors are not robust enough to support heavy furniture, thus preferring to sleep on the floor.