''To me, the decision is wrong because we have had a policy which has been very clear for a long time that it is not unethical to associate with a chiropractor if you believe that it is in the patient's best interest,'' said Kirk Johnson, the A.M.A.'s general counsel. Appeal Called Likely

The plaintiffs were to submit ''some kind of proposed injunction'' by Sept. 4, Mr. Johnson said, adding that a decision on an appeal would be made when the injunction was issued.

''I am absolutely convinced the A.M.A. will appeal,'' said the plaintiffs' attorney, George McAndrews. ''The four chiropractors have weathered 11 years of hell to call the A.M.A. and its co-conspirators into account.''

Michael Pedigo of San Leandro, Calif., a plaintiff, said he and other chiropractors wanted ''to be allowed to compete freely in the marketplace.''

He said A.M.A. policy had forbidden doctors from referring patients to chiropractors or accepting referrals from them, though some doctors ignored those rules. The boycott also extended to medical education, with doctors forbidden to lecture before chiropractic classes, he said.

Other plaintiffs were Dr. Chester Wilk of Park Forest, Ill, Dr. Patricia Arthur of Dayton, Ohio, and Dr. James Bryden of Sedalia, Mo.

Judge Getzendanner said the function of the A.M.A.'s Committee on Quackery formed in 1962 was to destroy the chiropractic profession.