Broken ankles is the product of an oppositions prowess over a defender. The act of faking your defender to the point where you are making them decide which way they should laterally move. Reacting with the cross over in a lateral defensive slide will cause you to roll your ankle thus being shaken to the point of a break. If it happens to you on defense but not to the point of a broken bone, you just got danced on in a athletic enviornment my friend.