The announcement came on the fifth day of women and girls providing their victim impact statements to a judge in a Michigan courtroom, where Dr. Nassar is being sentenced on multiple counts of sexual assault. More than 140 women and teenagers are expected to speak.

Many of those survivors who spoke have accused U.S.A. Gymnastics of turning a blind eye to the abuse, which occurred in Dr. Nassar’s home, at local Michigan gyms, at Michigan State University where he was an osteopathic sports doctor and at the United States women’s gymnastics’ team’s national training center run by Martha and Bela Karolyi.

The gymnastics organization severed ties with the training center, which was held at a remote Texas ranch, last week.

Jessica Howard, a former United States national champion in rhythmic gymnastics who served on the board from about 2009 to 2012, said the resignation of those top board members was a long time coming.

“Paul Parilla has been the architect of the USA Gymnastics board for as long as I can remember and is one of the people responsible for the broken culture in our sport,” said Howard, who was a teenager when Nassar abused her. “I truly believe that no one on the board thinks they are responsible for anything that Larry Nassar did to those girls, and that’s just sick.”

Parilla is a lawyer and a retired Marine colonel. His daughter, Jennifer, was a two-time Olympian in trampoline.

An investigative review led by the former federal prosecutor Deborah J. Daniels last year found that the board did not adequately address sexual abuse issues in the sport, and Howard personally found that to be true.