Attacking The Ankle
If you have ever twisted your ankle I don’t have to tell you how much pain that causes and how long the recovery takes. I remember having a bad sprain years ago and it was very painful. I was on crutches for about four weeks before I could walk with any pressure on my ankle. The angle is a complex joint of ligaments and bone. When it is manipulated in the opposite direction it was intended to work you will cause pain and injury.
I had a Martial Arts student training for a cage match years ago that had a bad ankle injury. Some Special Forces guys wanted to train so I mixed them with him for some great training for us all. We trained for a few weeks and then my student and a SF guy matched up. Went for a two minute round and they both did well. The second round though not so good. The SF guy had my student in a cinched ankle lock and was putting the pressure on it. I told my student he should just tap out, but he would not. Then I heard it Snap and it was loud. That tap out would have saved him a trip to the ER and a world of pain.
Conor McGregor a UFC Champion suffered a major ankle injury in UFC Fight 264 and had to be carried out on a stretcher with surgery to soon follow. Seems he stepped back on it and it gave away and crumbled. McGregor said he already had injured it and that weight shift finished it off.
Attacking the ankle is very tricky without some practice. The only way I would attempt to injure the ankle would be with a powerful stomp. But, if done incorrectly could damage your own ankle. So without training I would us this as a last attempt to cause injury. But, it can cause a debilitating injury to any attacker as all the primary targets that we have talked about will.