Fast Feet " Drills"

Does doing fast feet drills have any effect on a sprinters technique or assist in developing leg speed in young athletes?

By fast feet I mean rat-a-tap steps over about 1m.
Also athletes had hunched shoulders bent over at waist looking at their feet.

probably a waste of time

I think they could be effective only in as much as a lot of athletes try and do movement slowly.

I use that drill occassionally and emphasise a normal upper body and relaxation. But it is not one I use a lot of.

The way you describe this, i think i used to do this with my old coach once in a while… But i never liked it