It could have been a medical school amphitheater, with all the people observing as the patient's problems were detailed.

Instead it was Joe Theismann standing in a hotel ballroom, surrounded by almost 500 persons at a sports medicine seminar sponsored by the Maryland Podiatry Association yesterday.

"As a professional athlete, I am a walking encyclopedia of various injuries and proof that a body can be put back together again," the Redskin quarterback said.

In eight years of professional football, Theismann said, "I have been knocked out three times, broken my nose seven times. I have a staple in my left shoulder that holds it together.

"I've broken three ribs on the left side, two on the right. I have a hip pointer-that's a tearing away of the muscles-on the left side and it's the most painful injury anyone can go through. It feels like a hot iron.

"I have torn cartilage thanks to the Atlanta Falcons and a seperated left collarbone courtesy of the Dallas Cowboys. I also have had broken metatarsals and broken toes. Other than that, I'm a healthy human being."

Given this list of injuries, a man wanted to know, what would Theismann recommend to high school and college players who insist on playing hurt.

"I'm in a business where I have to show up every Sunday if humanly possible, because I'm at the pinnacle of professional sports. A young man is going to jeopardize his shot at the pinnacle if he plays hurts. His body is still developing.

"This is a do-as-I say, not-as-I-do situation. I would beg of a young man, 'Take care yourself. . .don't blow it all because you want to be a hotshot.'"

At another point Thiesmann said, "By the way, what you hear is hokum about putting (players) on drugs, just hokum. I haven't met a man who needed a pill to get him through a game."

A glib and often humorous speaker, Theismann described the conditioning program he maintains 50 weeks a year. Yet, he admitted, he feels most out of shape during the season.

"What you do from January to July determines whether the Redskins go to the championship. I get so out of shape in July its ridiculous," he said, explaining that a typical day involves so many meetings that it leaves only 1 1/2 hours for actual workouts.

Theismann runs, beating the drudgery with a transistor radio. He also plays tennis and racquetball daily. The latter game is his passion and most likely will be the sport he will pursue when this football days are over.