Trudi Kollar, known to the world as Emelia Eberle, was only 12 years old when she joined Romania's national team in 1976, KCRA-TV, Sacramento, Calif., reported.
During her career she earned 13 individual medals in international competition including an Olympic silver medal.
Kollar said mistakes in training or competition resulted in frequent beatings from Karolyi.
"In one word, I can say it was brutal," she told KCRA.
Kollar said Karolyi's wife, Martha, watched the abuse and sometimes inflicted her own punishment.
"Occasionally she scratched us. She stuck her fingernails in the back of our necks and she shook us," Kollar said.
Marsha Karolyi is currently the U.S. national women's gymnastic coordinator. Her husband, who is semi-retired, was a star commentator for NBC during the Olympics.
Attempts to reach the Karolyis for comment were unsuccessful.