Her ability’s called Violence Doughnut, an ability to increase the centrifugal force in her by 0.5 to 2 times, and she’s a Level 2. Centrifugal force, one of the basics when fighting, increases destructiveness, but her bones and muscles are as only tough as a human's, so her trait was that her bones will snap if she punched really hard.

Toaru Majutsu no Index New Testament vol.4 afterword