With hand and foot trikes, the rider makes a pair of front wheels change directions by shifting the center of weight and moves forward by rotating the rear wheel. The hand and foot trike can be also converted into a manual tricycle designed to be driven with both hands and both feet.[21][22] There are also new hybrids between a handcycle, a recumbent bike and a tricycle, these bikes make it even possible to cycle with legs despite a spinal cord injury.[better source needed][23]