Layback
This involves leaning or laying your body back as you move up. You pull on a surface with your hands (like a tree root or edge of a boulder), while your feet push against a surface. It’s called a layback because you lay or lean your body backwards or even sideways.
This allows the weight of your body to pull against your hands and push against your feet at the same time. Often there’s no platform or ledge for your feet, so when you lean back and press weight into your feet they will stay firm on the surface as your body moves up. This uses more than just gravity, but the push-pull action of your hands and feet to keep you on the surface.

