When you're 6'4" and moving along at a good clip, it's not a good idea to get your feet tangled. This kind of thing happens:
I'm now sporting an injury reminiscent of my youth skateboarding days when this sort of thing happened rather frequently. My first skateboard had steel wheels like you'd find on old roller skates and if they hit the slightest pebble you'd go flying.
It's not as much fun when you're my age.