LONDON (AP) — Three years ago, doctors reported that zapping a paralyzed man’s spinal cord with electricity allowed him to stand and move his legs. Now they’ve done the same with three other patients, suggesting their original success was no fluke.

Experts say it’s a promising development but warn that the experimental treatment isn’t a cure. When the implanted device is activated, the men can wiggle their toes, lift their legs and stand briefly. But they aren’t able to walk and still use wheelchairs to get around.