The small colored blocks are little tests for Jeff Kepner as he carefully picks one up by pinching it between his thumb and forefinger and then rolling his hand under it to cradle it in his palm before dropping it into a plastic box. Five months after the hands were sewn on in the nation's first double hand transplant, Mr. Kepner is in therapy four hours a day, five days a week, to gain more function with them.

"We're gradually getting back to normal, if there is such a thing," he joked, less than two weeks after returning to Augusta.

Mr. Kepner's recovery is going to be prolonged by the fact that the donor limbs were attached higher on the forearm, almost in the middle of the forearm on both sides, said Vijay Gorantla, director of the Composite Tissue Allotransplantation Program at the University of Pittsburgh Medical Center, where the transplant was done.

"He has to train more muscle in order to get function back with his upper limbs," Dr. Gorantla said. "And also the nerves have to grow over a longer distance to enervate or provide motor and sensory function to his transplanted hands. So we anticipate he will regain reasonable sensation and reasonable motor function by the first year."

Nerves grow about an inch a month and Mr. Kepner's have a foot or more to cover, he said. He might be helped in that by the single immunosuppressive drug he is taking, tacrolimus, which has shown the ability to help nerves regrow faster in animal studies but not yet in humans, Dr. Gorantla said. In fact, Mr. Kepner was part of a unique protocol at Pittsburgh that included a bone marrow transplant from the donor that so far seems to be working, he said.

"He has not had a single episode of rejection so far," Dr. Gorantla said. "And this is almost contrary to what we have observed elsewhere in the world."

After initially beginning therapy in Pittsburgh, Mr. Kepner is continuing now with Ray Domyslawski, an occupational therapist and certified hand therapist at The Hand Center at Doctors Hospital Rehab Health Centers. It might be stretching, using weights to strengthen his biceps and triceps, or manipulation skills like picking up the blocks. Part of what Mr. Kepner is doing is in his limbs but it is also working on his brain, Mr. Domyslawski said. Within the cerebral cortex, there is a "representation" of the hand on something called the motor homunculus, Dr. Gorantla said. After an amputation and lack of use, it can disappear.

"So by doing the manipulation tasks, we're redeveloping some of those motor patterns," Mr. Domyslawski said. "And we're also working on helping to establish the groundwork for some of the sensory reprogramming that has to be done also by the brain."

Because he doesn't have touch sensation in them yet, Mr. Kepner has to concentrate and watch his hands to ensure they are doing the task correctly. And it can be boring, he said. It leaves him tired, and he wakes up tired.

"I'm still not bodywise caught up yet," Mr. Kepner said. "It's more mental than physical because I really don't do that much physically, do I?"

"Well, you get a pretty good workout," Mr. Domyslawski said.

It requires patience, something that he said is in short supply at times. But he knows there will be many more months of this ahead.

"It's a matter of patience," Mr. Kepner said. "I've got nothing but time."