Brooke Shields explains her broken leg: Fall from balance board 'snapped my femur'

Brooke Shields has explained that a simple fall using a regular exercise machine caused her serious leg injury.

Shields, 55, said the minor tumble while working on a balance board "snapped my femur," speaking on the "Today" show in an interview segment released Thursday.

"I was on one of those balance boards that I have been doing every day," Shields explained. "It was just something that I like to do. I've done it on Instagram and I stupidly switched my focus and I flew up in the air and just hit perfectly."

Shields explained that the thigh bone, is "you know, the largest bone in the body."

The one-time Calvin Klein jeans model initially revealed the injury when posting an Instagram video Sunday of her in a hospital gown taking extremely tentative steps with metal crutches, non-slip socks visible on her feet.

"Broke my femur. Beginning to mend," Shields wrote in the post. "No matter what your challenge is, make a positive choice, for yourself, to move forward. #BeginningisNow."

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Shields continued to look forward to recovery in her "Today" show interview, which airs fully on Friday.

"I'm focusing on just recovery," she said. "This is really probably the biggest thing that I have to physically go through, but what am I going to do about it?"

The initial video sent shockwaves through Hollywood social media.

"So sorry!'s in your blood. Sending love," actress Glenn Close commented on Shields' Instagram post.

"I’m so sorry, let me know how you’re doing," wrote Sharon Stone, who offered to bring over food.

"So glad I got to see you baby you looked so well and beautiful and I know this is a tough one," wrote model Helena Christensen.  

In recent Instagram posts during the pandemic, the one-time Calvin Klein jeans model Shields has discussed working out during the pandemic to stay in shape.

Brooke Shields attends the Broadway opening of "Girl From the North Country " in 2020.

"My approach to working out comes from more of a rehab approach because I had a partial knee replacement and I’m sort of preparing to have a full knee replacement on my other knee,” Shields explained in one post. “It really stems from the maintenance aspect of continuing to activate my muscles. It really started off as me calling my trainer and saying, ‘Please, can you FaceTime with me and tell me what I can do?’ And it grew from there.”