On a rainy day in April 1978, Michael Harrison, then 14 years old and an eighth grader at Gaithersburg Junior High School, broke his neck during a gymnastics class when he tried, and failed, to perform a stunt called a running forward flip.

Since that moment, when he crashed head first onto a tumbling mat, Michael Harrison has been a quadriplegic--paralyzed for life from the shoulders down and totally dependent on the world around him for his slightest need.

Three years after that accident, Michael Harrison, strapped upright into a wheelchair, and his mother Carol, a bookkeeper who says the greatest hurt of her life was the devestating injury suffered by her only child, went to the Montgomery County Circuit Court seeking $3.5 million in damages from the county school system. "The way I felt was you send your children to school and you expect to get them back," Carol Harrison said in a recent interview.

After she came to accept the permanence of her son's injury and the unending cost of his care, money became the driving force behind the family's lawsuit, she said. "I don't think he needs to live like a king," she said. "I just think he needs enough to maintain his dignity." But the Harrisons left the courthouse empty-handed.

Their case is now in the Maryland Court of Appeals where it is the centerpiece of what could be a landmark legal battle about the way Maryland decides who should pay for the costs of accidents like the one that left Michael Harrison, now 19, a helpless quadriplegic.

The issue that has propelled the Harrison case into the appeals court is the state's doctrine of contributory negligence. It says that if a person contributes in any way, no matter how slight, to the cause of his accident, he cannot recover any money damages. Maryland, Virginia and 10 other states, as well as the District of Columbia, have retained that rule while 38 others have adopted rules of comparative negligence in which parties to an accident share its cost, based on the degree of their fault.

Michael Harrison's lawyers, Jacob A. Stein and Robert F. Muse, contend that the verdict in their case, which left Michael alone to bear the financial burden of his catastrophic injury, exemplifies the harshness of the contributory negligence doctrine. They have urged the appeals court to abandon Maryland's "all or nothing" rule and order a new trial for their client using the comparative rule.

"Human beings make mistakes, that is a fact of life, and the 38 states that have adopted comparative negligence are dealing with that fact realistically. The remainder are not," said Stein, who is the president of the D.C. Bar.

Even if contributory negligence was a factor in the jury's decision, the school board lawyers argue, the place for changing that doctrine is in the legislature, not in the courts, because the issue involves fundamental questions of public policy that should be left to lawmakers and not judges.

A change in Maryland negligence law would have a dramatic impact on the way juries and judges in the state award money damages in the multimillion dollar business of personal injury lawsuits. So the outcome of the Harrison appeal means high stakes for insurance companies, who absorb most of the costs of accidents, as well as for the lawyers who bring those cases to court and those who defend against them.

The lawyers for Harrison contend that the contributory negligence rule is grounded in outmoded and unfair notions about the assignment of fault that grew up in the significantly less complex world of the 19th century. Those notions include what one expert has described as the "puritanical view" that the courts should not be helping out wrongdoers who were in some way responsible for the harm that came upon them, as well as a need for a simple "yes or no" system for deciding who should pay for an accident.

"Even if Michael Harrison was responsible in a small degree for his injuries, there is no reason why that fact alone should absolve the defendants of all liability for their negligence," the attorneys argue in papers submitted to the appeals court. Comparative negligence is the better rule, the attorneys argue, because it "apportions losses on the basis of fault with each party bearing the portion of loss directly attributable to his conduct."

During the four days in July 1981, that the Harrison case was being considered by a Montgomery County jury, attorneys for the Harrisons argued that the school system had not properly supervised Michael or trained him to take care against the inherent dangers of amateur gymnastics. But, Rockville lawyer Paul V. McCormick, representing the school board, vigorously denied any wrongdoing by the school system and argued that even if there had been negligence on the part of the teachers, Michael had contributed to his accident and his injury because he disobeyed gym class safety rules and tried to perform his stunt behind his teacher's back.

After 10 hours of deliberation, the jury of three men and nine women returned a verdict in favor of the school board.

"It was a courageous thing to stand up and tell a quadriplegic that the people you sued are not responsible for what happened to you," said attorney McCormick recently.

Charlie Oliver, the jury foreman, said in a recent interview "we all kind of agreed that he Michael Harrison helped cause the problem." He added that he believed that the evidence showed that the teachers in the case "had not done anything wrong."

"I would have loved to give him some money," another juror said. "I think the whole thing kind of stunk that you have to go in there and say 'No,' " said the juror, who did not want to be identified.

In the Maryland appeals court, the Harrison case escalated into an unprecedented broadside on the contributory negligence rule and the defense against it was taken over by the Baltimore law firm of Semmes, Bowen & Semmes. The firm represents Maryland Casualty, which was the school board's insuror at the time of Michael Harrison's accident.

In the appeals court, attorney H. Thomas Howell and other lawyers for the school board renewed their assertion that "there was substantial and compelling evidence that the [teachers] were not negligent at all" and that Michael was fully to blame for his injury.

Howell contends that the issue of who should pay for the costs of accidents raises complicated social rather than legal questions.

"Maybe society has come to a point where it should take a different approach. My point is it is not a question of law. It's a question of social policy and loss distribution," Howell said, that should be resolved in the statehouse.

In court papers, lawyers for the school board and its insurer note that in the 31 of the 38 states that have adopted various comparative negligence rules, that decision was made by the state legislature. In the other seven, courts imposed the rule. Since 1966, legislative committees in Maryland have considered 20 bills that would have given the state a comparative negligence law. Two of those bills made it to the floor of the House where both were defeated.

The legislators "simply don't feel there is any crying need to tamper with the law," said attorney William F. Gately, a partner in the Semmes Bowen law firm who has lobbied against comparative negligence bills in behalf of the 150 member American Insurance Association.

Moreover, he said, the insurance companies contend that comparative negligence rules result in insurance companies paying out more money in damage claims. According to Gately, the upshot of that will be "the people who will pay will be the people who buy insurance," who will have to pay higher premiums.

Critics of contributory negligence law contend however that the law requires juries to throw out a lawsuit even if the injured person's fault was just 1 percent of the cause of the accident. Maryland's Lt. Gov.-elect Joseph Curran Jr., who chaired the Senate Judicial Proceedings Committee when it considered comparative negligence bills, disagrees.

"In the real world of trying cases . . . I know full well that juries . . . don't throw out a case against a plaintiff who was 1 or 2 percent at fault," said Curran, who is a veteran trial lawyer. But, Curran said, "if you are 40 percent wrong . . . you caused the accident . . . why should you recover?"

"When 12 men and women get in that jury box they do the right thing," said Curran, who opposes any change in the law.

Curran said that lawyers who specialize in personal injury cases have opposed the comparative negligence doctrines because they are afraid that lawyers for defendants will "raise some smokescreen" to try to show fault by the injured person, even if there was none, and thus reduce his recovery of money damages.

"If you've got a strong case, you don't want anybody chipping away at comparative negligence, hinting the plaintiff did something wrong," Curran said.

Robert R. Michael of Rockville, president of the 1,000-member Maryland Trial Lawyers Association, agrees that the comparative negligence system can cut both ways for injured clients, reducing their money recovery in some cases but at the same time allowing for some money damages even if they had contributed to the cause of the accident.

"I'm willing to take the lumps," said Michael. "The system is supposed to place the fault where it belongs."

No doubt the biggest stake in the court of appeals decision lies with Michael Harrison, who now lives at a nursing home called Winning Wheels in upstate Illinois. His 24-hour a day care costs about $20,000 per year, and could run more than $1.6 million for his lifetime, according to his mother and court testimony. Michael attends school, and he said, hopes some day to be as independent as he can.

The cost of his current care is covered by a private insurer, but there is a cap on what the company will pay out. The damages Harrison is seeking would be used to ensure continuous care and enable him to live a more independent life.

"It costs an awful lot to live being a quad, especially trying to live like a normal person would and not in an institution," Harrison said during a telephone interview, "so hopefully if I win [in the appeals court] it would compensate for that."

If he loses, Harrison said, "I think I can handle it better now than the first time" when, he said, he was hurt and "very surprised" by the jury's decision against him.

"Now, I guess I'm more realistic," he said.