>>12090800Forward extrusion reduces chance of toppling forwards.
Backward extrusion reduces chance of toppling backwards.
While you have forwards momentum, your chance of toppling forwards increases, and your chance of toppling backwards decreases. Additionally, it's really bad to topple in a direction you already have momentum in as you fall much harder.
Since humans move forwards and are most likely to topple while moving, forward toppling is both more likely and more dangerous than backwards toppling, so obviously we're minmaxed to be less likely to topple forwards.
This minmaxing does lead to us falling backwards occasionally, but it's unlikely to result in even the slightest bit of harm.
