The achievement is no mean feat due to the inherent limitations of training a system where humans are physically attached. Where AI can usually take as much time as it likes to master a new field, amputees may only have 15 to 20 minutes before they have to stop. You also can't put wearers in danger. A fall might provide useful data, but it wouldn't be pleasant.

This is far from ready for real-world use. Among other challenges, the scientists would need to verify that this works with inclines, stairs and rough terrain. It's also wired, so amputees still need to visit the lab. Even so, it could be a breakthrough. Amputees could spend less time in clinics and more time enjoying their freedom. And if there's ever a wireless version, patients might not need to come back -- they could tweak prosthetics when it's convenient and carry on with their day.