With the aid of a chemical injection, electrical shock, and robotic harness, researchers are now able to help rats with spinal cord injuries walk again. The process has been in the works for five years, and today it can help rats with paralyzing lesions not only walk, but even run and traverse obstacles like a small flight of stairs. It works like this: first, the rats are injected with a chemical solution that helps trigger certain cellular responses in the spine, and a few minutes later the spinal cord is given an electrical shock to help stimulate the nerves that control leg movement.

The rat is then placed in a "robotic postural interface" that allows them to walk voluntarily — the harness keeps the rat from falling over, but doesn't provide any help when it comes to forward movement. "Our rats have become athletes when just weeks before they were completely paralyzed," said researcher Grégoire Courtine. He says that "it's difficult to predict" how the process will affect humans, but we imagine the robotic harness will be even more terrifying when it's big enough for a person.