What exactly are these "hobbles" for?

This made me sick to watch...hey lets tie a horses legs together with a full length led rope on and then run at them to try and get them to move!!! good idea...NOT! This is terrible! The guy is using fricken twine! What a great way to hurt the poor horses. Not to mention is is tying it around the horses tendons without any sort of padding! And when the grey horse moved away he just left it tied around the pastern! This is terrible! I can understand that hobbles are a training tool, but they need to be used correctly (and not just pieces of twine some idiot cut off of a bale of hay). And those foals should have those super short leads so that when they run away (and I don't blame them) he can grab onto them and they wont step on the rope and hurt themselves. I mean come on, if he is dead set on using full length leads then he should at least have breakaway halters!!! Ugh.