You know, there's a reason why crabs walk sideways. [VID: Why do crabs walk sideways? Crabs move faster and easier walking sideways. They have stiff, jointed legs. Their legs are attached to the side of their body. Their joints, unlike human knees, bend outwards, making it easier to move sideways. Crabs have four pairs of walking legs, plus a set of claws. In walking sideways, the crab avoids the danger of tripping over its own feet. A few crab species can walk forward. These species have shells