You can see very little happens on each stroke, that's important. If you're making progress too fast the dreads are not going to end up smooth and tight. Now that's not to say each stroke can't be fast, normally your hands are moving way faster, this is in slow motion so you can see what's going on despite the low frame rate.

Check out the fingers rolling back and forth as you backcomb, not twisting, just back and forth, this helps keep the dread round.

You start at he roots and backcomb until you reach the tips.

When too much hair begins to bunch forward combing through it will make loops and loose spots in the dread. Check out the hand-over-hand action used to pull this hair back before it starts to bunch up and cause problems.

I'm not making it look easy...it is easy. Yes, mom can pull this off. Take your time until you get the hang of it. The more strokes you have per inch of backcombed hair, the smoother and tighter the dreads will be. So you want lots of short fast strokes, and you want to be slowly progressing from the roots toward the tips.