Head injuries are frighteningly common.

Few people realize that a million Americans each year suffer such injuries. According to the National Head Injury Foundation, 70,000 to 90,000 of those are permanently disabled, while 100,000 to 200,000 suffer serious memory loss or concentration problems.Predictably, most head injuries happen to people between the ages of 15 and 24 - those who tend to be more prone to risk taking. Some are comatose for days, weeks or even months, and afterwards require various forms of speech therapy and physical therapy to help them recapture even a semblance of a normal life.

Such was the case with Karen Lambert, a happy and healthy California teenager who, at age 16, suffered a serious head injury when she was involved in an automobile accident.

After spending 81 days in a coma, she awoke to cope with a paralyzed left side, similar to that suffered by stroke victims, a severely damaged optical nerve causing double vision and reduced visibility (about 15 feet), paralyzed vocal chords, and brain damage so severe that she was unable to utter a complete sentence. Her cognitive abilities were so diminished that she was unable to control her bladder or care for her own needs.

Over a period of many months Karen underwent intensive therapy, but her progress was slow. Finally, her neuropsychiatrist announced that nothing more could be done.

But Carl Lambert, a computer scientist and Karen's father, refused to accept that prognosis and resolved to apply his own creativity to the problem. Lambert developed computer programs designed to stimulate the areas of the brain that facilitate short-term memory and concentration.

"A computer," he says, "is non-threatening. We say, `I can beat this thing - it's only a machine.' "

His computer programs actually do "the same thing as a therapist, but they do it longer and don't complain as much."

The memory loss is the key to understanding the head injury victim, Lambert says. Most of us are capable of dealing with multiple variables at several levels. While we are carrying on a conversation with one person, we may have several other thoughts going through our minds.

"While you're asking me questions and even listening to the answers, you may be thinking about what you're going to do later, or what your boss said to you earlier. You may be doing some cooking inside the house, but run outside to change the water or do some outside work. If your memory was impaired, you would forget about the cooking, and your house would burn down. The head injury victim has to cultivate the memory at least enough to carry on normal day-to-day activities."

Since his daughter's accident, Lambert has devised 40 programs "from super-simple programs for those just emerging from a coma to very complex things for those who are progressing at a faster rate." They are designed to teach the damaged brain a sequential order and demonstrate the necessity of strategy and concentration.

Karen's favorite game, written by her father, is "Fun With Poker," which displays 25 randomly selected cards in a grid, presented consecutively, then asks the player to create the 10 best poker hands. Lambert says this game, which is fun for the player, actually teaches pattern recognition and problem solving at the same time.

In a game called "Traveling On," the player selects a trip destination and alternates turns with the computer in developing a list of items to take along. The player must remember the entire list in correct order each turn.

A memory-challenge game displays two to eight letters, replaces them with numbers, then asks which letter is beneath each number. A synonym game displays key words with four possible words as synonyms and asks the player to identify the correct word. A logical math game displays a math equation, then offers a choice among the four next logical steps. Some games can be played at a variety of levels and timed in order to increase the challenge.

Karen says she loves these games, and during her most intensive therapy she was doing them "all day and all night."

Her father sees Karen, now 22, as a "very tenacious person" who has made tremendous progress because she enjoyed the process and was determined to master it. He believes that her memory has recovered to approximately 90 percent of what she had prior to the accident, and "in a mental sense she functions very well." She is still restricted by her physical weakness, especially her left side, and her visual impairment.

To those who meet her for the first time, Karen's physical handicap and her slow, breathy speech may seem to mask her very real mental acuity. While she is using the computer it is evident that some of her fingers operate with less than full dexterity, but she is mentally alert and animated as she works, and the finished product does suggest a remarkable recovery.

The computer tells only part of the story, of course. Long hours of physical therapy have restored most of the use of her left side; she walks with only a slight limp, speaks slowly but clearly, and takes care of her own hygiene.

Carl Lambert teases his daughter constantly, and she obviously returns his affection. As she demonstrated the ability to write a letter on the computer, he playfully warned her that she should not write anything "saucy" for fear it will "turn up in the newspaper." Responding to his warning, she carefully wrote, "While I am writing this letter, everyone is watching everything I write."

The same theatrical humor inserted itself in his presentation to physical therapists and other interested visitors at the Holy Cross Hospital's Quinney Rehabilitation Institute. Expressing pleasure to be in Utah for the first time, he asked, "By the way, where's the Salt Lake? I heard that a couple of years ago it was downtown!"

Since 1984, Lambert and his daughter have conducted regular tours throughout the country, lecturing and demonstrating the advantages of his computer programs. They speak at hospitals and rehabilitation centers and to speech therapists and other interested groups in an effort to convince them of the medical advantages. Their next tour will be in October and will include upwards of 25 cities.

Lambert's programs are now being used in more than 500 medical facilities in the United States and overseas, including Spain and Australia. He also offers computers for purchase at cost, and is working on additional training materials involving videotapes. Lambert says the funds he raises are funneled completely into the Karen Lambert Foundation in Ramona, Calif., a non-profit organization dedicated to assisting those who suffer from the frightening effects of head injuries Lambert believes it is vital that he and the foundation continue to work to train these people to function day to day and to perform certain jobs. He offers a simple, straight-forward approach where results can be measured.

He recalled a sensational incident in California in which someone dropped a brick from a viaduct through the sunroof of a car and caused severe head injuries to the driver, sending him into a coma. The tragedy, he said, is that people around the country were more interested in the sensational nature of this crime than in the debilitating effects of the head injury on the victim.

That is why more publicity is needed, he says, why he and Karen will continue to travel and speak about it, and why he will continue to develop high-technology components for therapy.

It is an arduous, time-consuming process that Karen and Carl Lambert execute with devotion and gentle good humor.