The video just shows that the weight was too heavy for you. If you drop the weight back and focus on the form you'll find it will come more naturally. I haven't done my 1RM in a while and have been focusing on form and activating the right muscles. It's worked really well for me (have a look at my recent video). A belt wouldn't help the lift in the video at all, you don't have enough power in the bottom and the setup is wrong
This looks bad and will make icecold cry
This looks bad and will make icecold cry