The word "rehabilitation" is much used in the medical and hospital world. But 60 years after Dr. William J. Mayo said, "Rehabilitation is to be a master word in medicine," it is still more spoken than practiced.

The test of true rehabilitation is this: Has the patient been trained to live again? To care for him- or herself? To get around, to work, to enjoy the good things, all to the greatest extent possible?

This idea was still revolutionary when Mayo, one of the founders of the Mayo Clinic, made his 1925 prediction. And his making it had no huge effect. The young Franklin D. Roosevelt, for example -- after contracting polio and teaching himself to walk to an extent, swinging himself along on his crutches -- had little success in interesting orthopedists to do more to help other victims after acute treatment ended.

True, there was a small but growing group of physical therapists, and there were some doctors practicing what they called "physical medicine," both trying to restore useful function to the disabled. But it took two cataclysms to establish rehabilitation as important.

One was polio, which struck in a series of ever more devastating epidemics.

In 1940 an angry, self-made Australian polio nurse, Sister Elizabeth Kenny ("sister" is a British nurse's title), descended on the United States. She saw polio victims painfully and futilely encased in casts and splints to keep their limbs "straight." She said: Take them out of the casts, retrain their muscles and they shall walk. Many did. The treatment revolution she started forced the National Foundation for Infantile Paralysis (today's March of Dimes) to begin training physical therapists to apply the new methods.

They became a valuable nucleus when the second cataclysm, World War II, began creating disabled veterans, shipped in ever larger masses to military and veterans' hospitals that at first had little ability to return them to useful lives.

One far-seeing military doctor, Howard Rusk, did most to change that. Backed by the Mayo's Dr. Frank Krusen (who had been hired by "Dr. Will" Mayo to establish physical medicine at that clinic and train young doctors in it), Rusk preached "rehab" to the military and Veterans Administration. He and Krusen made "physical medicine and rehabilitation" an accepted medical specialty. Rusk later founded what is now the Rusk Institute of Physical Medicine and Rehabilitation at New York University.

Rusk said 15 years ago that most hospitals and doctors were still giving rehabilitation more lip service than time, staff and space, while at least 10 million Americans needed rehabilitation but were not getting it.

Rehab doctors agree that the situation has improved, though not yet sufficiently.

When Rusk made that statement, there were only 700 trained "physiatrists" -- MDs practicing this specialty -- in the entire country. Now there are 2,000. "Right now we need 2,000 more," says Dr. John Goldschmidt of the new National Rehabilitation Hospital.