Ralph Sampson, the Houston Rockets' 7-foot-4 center, fell so hard in tonight's game against the Boston Celtics that doctors feared he might have broken his back.

Teammates, opponents and fans in Boston Garden were stunned as Sampson lay on the court and told a doctor that his right leg was numb and that he couldn't move it.

But within hours of being rushed to Massachusetts General Hospital, he was back at the team's hotel with nothing more than a badly bruised back and a stiff neck.

It appeared much worse than that when he fell 2:19 into the second period while rebounding under his team's basket.

"He went up for a two-handed rebound," teammate Robert Reid said. "He seemed to skid on the floor. He was scared . . . Anyone would be at that time with a doctor asking if you can feel this touch or that touch . . . The only thing he was saying was: 'Oh, my God. Oh, my God.' "

"I knew it was bad when he went down," Houston Coach Bill Fitch said. "I was concerned as soon as he hit. He was in a lot of pain. He finally got to the point where the pain let up a little bit. And he could say where he felt sensations. I'm sure he was scared to death. Someone asked: 'Can you feel something?' And he said: 'No.' "

A Celtics spokesman, Jeff Twiss, said the feeling and motion in Sampson's right leg improved at the hospital and that Sampson "wanted to talk with his mom" in Harrisonburg, Va., "so she wouldn't worry."

On the floor, Sampson complained of nausea but remained conscious. After being taken to the locker room on a stretcher, he was able to recognize teammates.

Dr. Thomas Silva, the Celtics' team physician, said that initially the fall "resulted in a definite loss of the right neurological process in his right leg," and that there was "a possibility of a fracture of the mid-back."

At the hospital, Silva noted "improvement in the right leg is continuing," and added: "I think we're going to be all right, but it does scare everybody."

Sampson bruised his upper back, but his blood pressure and other vital signs were normal at the hospital. Sensation and movement on of left side was not a problem.

Finally, doctors found that X-rays and a CAT scan of Sampson's head, legs and neck revealed no injury and sent him on his way.

"If he needs a little R&R in the Bahamas," Fitch said. "I'll take him there myself."

Sampson, 25, former all-America at the University of Virginia, was the game's leading scorer with 17 points when he was hurt; Houston led by 53-51, but lost, 114-107.

The Celtics won the game, 114-107, after Scott Wedman broke a 97-97 tie with the first of two consecutive jumpers.