The ATFL or anterior talofibular ligament is the most common ligament in the ankle that people tear/sprain/injure.
It attaches the talus and the distal head of the fibula.
The ATFL is typically torn or sprained when the ankle moves into inversion and plantar flexion (toes pointing in and down) at an extremely high velocity.
Unfortunately, ligaments don't return back to their original shape. Once they are sprained, or stretched, your ankle remains less stable and you are more likely to re-injure yourself. A physical therapist can give you targeted exercises to rebuild the muscles around your ankle and help improve your motor control and balance to decrease your risk of re-injury.