The 54-year-old Larry Nassar is accused by more than 265 women - including Olympians, gymnasts, and collegiate athletes - of molesting them over more than two-decades.
Larry Nassar, the former USA Gymnastics doctor who sexually abused hundreds of girls and young women for decades under the guise of medical treatment, was sentenced on Monday to an additional 40 to his pre-existing 125 year prison sentence.
Nassar already faced a lifetime behind bars for two prior sentences after pleading guilty to sexually assaulting women and girls in his role as a high-profile sports medicine doctor at USA Gymnastics and at a Michigan State University (MSU) clinic.
"This now ends the criminal legal proceedings involving Larry Nassar. I realise that it does not end the emotional and physical suffering he has caused," Judge Janice Cunningham said in a Charlotte, Michigan courtroom after imposing the maximum sentence under a plea agreement.
He had previously been sentenced to 60 years in prison on child pornography possession charges in December, and up to 175 years in prison on sexual abuse charges in January.
The last of the three sentences was handed down Monday over abuse Nassar committed at the Twistars gymnastics training center in Michigan.
TRT World's Tetiana Anderson reports.
Nassar addressed the court in a brief statement lasting less than a minute, offering an apology similar to the one he offered at the January sentencing.
"The words expressed by everyone that has spoken, including the parents, have impacted me to my innermost core," Nassar said.
"It's impossible to convey the depth and breadth of how sorry I am to each and every one involved."
Many of his victims and their family members confronted Nassar during emotional courtroom hearings over the past three weeks, which climaxed Friday as a father of three victims lunged at Nassar in court but was subdued by police.
More than 150 victims spoke at a marathon seven days of hearings in January, and 48 others spoke out in court for the first time last week.
Their descriptions of lasting emotional scars, and criticism of institutions that allowed Nassar's abuse to go unchecked for decades, have shaken US amateur athletics.
The US Congress passed a bill enshrining new athlete protections into law.
The entire board of USA Gymnastics and some of the university leadership have been forced to step down.
MSU, the gymnastics governing organisation and the US Olympic Committee have all come under scrutiny and are facing various investigations.