Firas Zahabi:
The Heel Hook is the Knock-out punch of grappling, it came be a applied from a variety of positions and can achieve a break in an instant.
Many BJJ schools ban this maneuver and claim that it is too dangerous and is sometimes consider a “cheap” move. I couldn’t dissagree more. The Leg lock is a highly technical submission hold. In regards to safety, the leg lock can cause a break far faster then a armlock or Kimura and should be train with a higher level of precaution.
When training legs lock be sure to apply pressure gradually if at all for that matter. I personally don’t apply pressure and simply focus on make the tights possible grip, hold for a few seconds and release. My objective is to practice the powerful submission without Hurting anyone.