Damage to the spine can stop electrical signals from the brain getting through, causing paralysis.
Researchers have put an electronic implant into the brains of monkeys with paralysing spinal injuries. The implant sends information wirelessly from the brain, via a computer, to a second implant on the monkey's spine. This sends electrical signals to the legs, telling them to move.
I'm really excited by this step forward in spinal injury treatment - although it'll be years before a technique like this could be used safely in humans.