Lawrence G. Nassar in 2008. (Becky Shink/Lansing State Journal via AP)

Lawrence G. Nassar, the longtime team physician for the U.S. womens’ and Michigan State gymnastics teams, was charged Wednesday with abusing nine female athletes, some younger than 13, in what Michigan’s attorney general called “horrid sexual assaults under the guise of medical procedures.”

Bill Schuette, the state’s attorney general, said in a statement that the sexual assaults occurred in Nassar’s home treatment room, at the Michigan State Sports Medical Clinic and at the Twistars Gymnastics Club in Dimondale, Mich., where he was the facility’s physician.

Nassar already has been charged separately with criminal sexual conduct in relation to a nonpatient younger than 13 and with federal child pornography possession offenses. Wednesday’s charges added 22 counts to the existing charges.

Nassar, 53, was originally arrested in November on the pornography charges. Since then, dozens of other women have come forward in lawsuits alleging that he committed assaults during exams ranging from inserting his finger in their vaginas and anuses to fondling their breasts.

Nassar has denied the charges, claiming he was conducting legitimate medical procedures.

The charges announced Wednesday involve a total of nine girls and young women ranging in age from 13 to 16 at the time of the alleged offenses, which occurred between the years 2000 and 2016.

“Dr. Nassar preyed on these young girls,” said Schuette, using “his status and authority to engage in horrid sexual assaults under the guise of medical procedures. … The girls abused by Dr. Nassar were so young, so innocent, that they didn’t fully understand what Nassar was doing to them until many years later.”

In an affidavit, a Michigan State University police detective described what she learned from interviewing the alleged victims.

One said she was sexually assaulted by Nassar for the first time at the age of 10. He “would come on Monday night to treat the gymnasts” at Twistar and in a backroom “pulled her leotard up and touched her vagina” with his bare hand and fingers.

She stated that “she and the other gymnasts would talk about Nassar,” according to the affidavit, and “discuss how he was ‘touchy.’ ” At the time, she did not question Nassar “because he was doing the same to other gymnasts she knew. … [She] stated that because she was so young, she really didn’t know anything was wrong.”

Another alleged victim, now 21, said she was “sexually assaulted by Nassar ‘more times than she could count’ ” after seeing him for treatment starting at the age of 10 or 11.

He would have her lie on her side and put a blanket over her, according to the affidavit, and “would stand behind her, vaginally and anally penetrating her with his fingers.”

Another alleged victim said what Nassar was doing was “common knowledge” but that no one questioned him “because of his position and reputation.”

Before the revelations, as The Post’s Rick Maese and Will Hobson wrote Feb. 16, “Nassar was a revered figure in American gymnastics. He is a nationally renowned expert on gymnastics injuries and rehabilitation. He served as the team physician for the U.S. men’s and women’s Olympic gymnastics team from 1996 to 2015, working four Olympic Games in that time. He was a sports medicine physician and a faculty member in MSU’s Division of Sports Medicine in the College of Osteopathic Medicine. He taught sports medicine at MSU’s College of Osteopathic Medicine and was the team physician for Michigan State’s women’s gymnastics and crew teams. He treated athletes, with specializations in gymnastics, dancers and cheerleaders, according to his website.”

In September, two former gymnasts told the Indianapolis Star of the allegations. One of them filed a report against him with Michigan State police. Michigan State suspended him and then fired him in September.

Nassar is scheduled for arraignment Thursday.