if you notice in a couple of my flight video snippets, you can see I'm wearing a backbrace, with a hook on the front, where you attach the "stropp" rope" that runs between both kite line handles.
Being "hooked in" you take the load off your shoulders/arms, and helps direct the energy to your legs.
Most all the buggy drivers are "hooked in" too.
You really have to respect the power of these kites, you can get hurt very easily in one wind gust and be pulled face first across the sand, or have an OBE (out of buggy) experience. If you google on u-tube, the are many video clips of people lofted up 30-40 feet or more through the air, some people like to intentionally jump too...........no thanks.
https://www.youtube.com/watch?v=FlwH8NldMw8