While most 5-year-olds are advancing to learning the alphabet, Christie Martinez must revert to infancy and relearn to sit, crawl and walk.

The Clovis, N.M., girl was born two months premature and weighed 2 pounds, 8 ounces. Doctors say the early birth cut off some oxygen to the child's brain and affected her motor coordination.The wheelchair-bound Christie now is playing catch-up with twice-daily therapy at Primary Children's Medical Center.

Christie was brought to the Salt Lake children's hospital for an operation to correct defects associated with cerebral palsy - a motor disorder linked with premature births.

Spasticity in Christie's legs had prevented her from walking normally, until three weeks ago when doctors severed abnormal nerve fibers in her spinal cord. The procedure - a selective dorsal rhisotomy - was performed by Dr. S. David Moss, a pediatric neurosurgeon, who said the surgery has been done at Primary Children's only since 1985.

"Christie used to walk on her tiptoes," said her father, Mike Martinez. "Her legs would scissor, with one leg catching on the back of the other, making her very clumsy and causing her to trip and fall a lot."

According to Moss, the tightly constricted muscles in Christie's legs and trunk that caused the awkward movements were loosened, and she is now in the recuperation phase.

Stretching and strengthening her underdeveloped muscles is improving the quality and ease of her movements.

Moss, who is one of a handful of physicians in the United States who perform the specialized surgery, explained the procedure: "The lower back is opened where the nerves controlling the legs emerge from the spine. Specific bundles of nerves are identified and divided one by one into the separate fibers that comprise them.

"A tiny special probe is used to single out fibers and deliver electric stimulation," he said. "By watching the reactions of muscles controlled by the fibers, we can tell which fibers are contributing to spasticity. These are severed.

"The defective nerve fibers interfere with the normal message-reaction sequences of the nerves and muscles, causing spasticity," Moss said.

Although it could take up to a year before she could walk, Moss said Christie is a good candidate for a complete recovery.

Christie receives physical therapy to relearn basic progressive steps to walking. "First she must learn to roll, then roll and push to a sitting position and then a holding-sitting position," said Sally Yamada, Christie's physical therapist.

"Next we will teach her to crawl on her hands and knees and kneel tall on her knees to strengthen her hips before we can teach her to walk," Yamada said.

"It's like reprogramming her brain," said Mike Martinez. "Because of the spasticity, Christie learned to use her muscles abnormally. Now she needs to learn the right way in order to develop muscles she has never used before."

Christie will continue to receive physical therapy and occupational therapy on a daily basis after she leaves Primary Children's September 2.

"Christie will receive therapy through the school system in Clovis," said her mother. "She will attend regular kindergarten in the morning and therapy in the afternoon. It'll be like a full day of school for her," Rose Martinez added. "The occupational therapy develops the finer motor skills."

Even though Moss predicts it could take six months to a year before Christie can walk without support, her father is betting she will be walking before Christmas.

"She is a very determined little girl," he said. "The way she used to walk took a great deal of effort, but she kept trying until she found a way to make it easier on herself."

"Christie will be her own best judge on when she'll be ready to get rid of the wheelchair. She has a real desire to walk normally," said her mother, Rose. "Before we came to Salt Lake City for her surgery, she said she wanted to run and play without braces."

Mike Martinez, who likened Christie's surgery to Neil Armstrong's first step on the moon, said the family has taken the big step. "For Christie there is no looking back, only ahead with a much brighter future."

Moss said the real payback is seeing how excited and happy the parents are with the improvement in their child following the surgery. "Most parents feared their child would be trapped in a spasticity with no hope of walking."

The Salt Lake Jaycees raised $500 to pay for the child's trip, while the group's New Mexico affiliate contributed $2,000 more. The Salt Lake group also arranged for housing Christie's parents and her 7-year-old brother, Charles.