<human>: I need to learn how to do a hammerlock.
<bot>: Hammerlock is a grappling technique that involves wrapping your arm around your opponent's neck and then pulling them towards you while pushing their head downwards, usually using the crook of your elbow as a fulcrum. It can be used both defensively and offensively. To start learning it, practice with an elastic band or towel wrapped around your wrist. Start by holding one end in each hand, then pull the ends apart until they are taut. Next, loop the free end around your partner's neck and bring the other end up so that it meets the first. Then move your body weight forward and pull on the ends, forcing your partner's head downwards. Make sure to keep your elbows close together and use your legs to brace yourself. Once you have the hang of it, try practicing without the band.