The lock twist as is also refered to as leg twist. It is created by twisting a pair of bubbles together. (To really "lock" the lock twist you can push the rest of the balloon through the middle of the bubbles after you make the twist).

	The lock twist can be done at speed by doing the middle twist first then folding over the balloon and twisting them together.
	To make a quick yet precise lock twist twist the first bubble then bring the balloon back and twist it to the first twist.
	Sometimes a lock twist is needed at the start of a balloon. To do this simply wrap the knot to the second twist.

Technically, the lock twist is the last twist that locks together a chain of bubbles of any amount so it could have three or more bubbles in it but for the sake of clearness when a lock twist is mentioned in these instructions it refers to a 2 bubble lock twist unless otherwise stated,

 

The classic balloon dog is made from three lock twists