Self-Defense - Judo - Okuri eri jime
Human Weapon: This video tutorial shows you how to do an Okuri eri jime. Okuri-Eri-Jime (送襟絞) is one of the twelve constriction techniques of Kodokan Judo in the Shime-waza list.

Self-Defense - MMA - Double Leg Takedown
Human Weapon video tutorial: The double leg takedown (colloquially simply known as a double leg or even double) involves grabbing the opponent with both arms around the opponent's legs while keeping the chest close to the opponent, and using this position to force the opponent to the ground.

Self-Defense - Pankration - Achilles Leg Lock
Human weapon: This video tutorial shows you how to do an Achilles Leg Lock, from Pankration. An achilles lock (also called an achilles hold or achilles squeeze) is a compression lock that involves pressing the achilles tendon into the back of the ankle or lower leg.