In a new online trend, people are scuttling, crawling, and bounding around on all fours while filming themselves – and their videos are getting a lot of attention. The practice is called quadrobics , and it's quite the spectacle. Quadrobics evangelists claim the movements promote fitness, strength, mobility, and even spirituality, as a chance to reconnect with nature and the "primal" self. The word quadrobics comes from quattuor (Latin for four) and aerobics (exercise that is rhythmic and