Sarah Michelle Gellar, most recognized for her starring roll on Buffy, The Vampire Slayer, is done battling the dead — but still fights chronic pain due to scoliosis.

Gellar says her childhood didn’t help the condition. She told Hudson Valley Scoliosis that even her backpack made the condition worse.

“I grew up with, and I still have, major scoliosis. Growing up in Manhattan, you had your school bag, but we were so trend-conscious, nobody wanted to put a backpack on both shoulders, so almost all the girls I grew up with have it to some degree, because we all were so lopsided.”

Causes of Scoliosis

Let’s be clear now, Backpacks do not cause scoliosis. The weight of an overloaded backpack can put more pressure on your back and shoulders and cause strain, or back muscle fatigue. It can also encourage slouching or poor posture which can lead to several back conditions.

Some people are born with it, others like Gellar were probably diagnosed as a pre-teen. Most cases do not require surgery. Gellar has said she treats her condition by using a treadmill on a regular basis, physical therapy, and pilates.