Mr. Summers can stand for up to four minutes at a time, or up to an hour with assistance. He received extensive physical training. His spinal cord had to be retrained to produce the muscle movements needed to stand and take assisted steps on the treadmill.

The treatment has also helped him regain some control over his bladder.

Researchers are calling his progress a medical breakthrough. Professor Harkema says there could be a day when Rob Summers and other paraplegics like him will be able to walk again.

But there is still a lot more work to do to reach that day.

Mr. Summers was completely paralyzed below the chest, but he did still have some feeling. The scientists say they do not know how the treatment would work with patients who have no sensation at all below the injury.

Also, the researchers point out that they have studied only one person so far. And Mr. Summers was in extraordinary physical condition before his injury.

Money for the research came from the Christopher & Dana Reeve Foundation and the National Institutes of Health. Professor Harkema is director of the Reeve Foundation's NeuroRecovery Network.

The eleven-member team also included scientists from the University of California, Los Angeles, and the California Institute of Technology.

And that's the VOA Special English Health Report. You can watch a video report about Rob Summers and his treatment at voaspecialenglish.com. I'm Steve Ember.