Self-Defense Sambo - Leg Sweep
Human Weapon video tutorial: Leg Sweep or leg trip refers to a technique in which the combatant performing the leg trip uses his or her own leg(s) to off-balance an opponent, hence causing the opponent to fall to the ground.

Self-Defense - Bokator: Double Elbow Slash
Human Weapon: This video tutorial shows you the Double Elbow Slash trick from the martial art Bokator

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.