Trapped Climber's Amputation 'Rational'

May 6 -- For Aron Ralston, his arm pinned under an 800-pound boulder that he could not move in a remote Utah canyon, the choice was no choice at all.

The mountain climber used a pocketknife to amputate his arm, but first he realized he had to smash the bone, because his knife was not sharp enough to cut through it.

"He actually broke his bone when he realized and decided that he was going to do the amputation," Ralston's mother, Donna, said today on ABCNEWS' Good Morning America.

"He actually forced his arm against the boulder and broke the bone so he would be able to cut through the tissue, because he knew from his experiences that the knife he had wasn't sharp enough to actually cut the bone," she said.

Aron Ralston, 27, is an extremely experienced climber who has also had search and rescue training, so he was able to think clearly in a situation in which many people might have panicked, his parents said.

"He said within the first hour he had identified he basically had four alternatives: someone would come along the trail, he would be able to chip away at the rock and free his hand, he would be able to rig up something with the ropes and equipment he had to move the rock. If all else failed, he said he knew he would need to sever the arm," Larry Ralston said.

Once he made the decision of what he had to do, he put his first aid training to good use.

"He had a long time to think about it and he … had some idea of what to do and how to apply the tourniquet correctly, and actually, he lost very little blood," Larry Ralston said. "The doctor indicated that he did not even have a blood transfusion during the transport or at all. So, he was lucky in that respect."

After breaking his own bone and then sawing through his arm, Aron Ralston rapelled down from the position where he had been trapped and hiked five miles before two tourists found him on Thursday.

Successful Operation

His hand was recovered from under the boulder on Sunday, but doctors determined that it was too badly damaged to be reattached.