Early acceleration rhythm?


I have a question about how the timing of the recovery leg’s drive past the support leg in the early acceleration affects performance.

The moment the support leg touches the ground, how far should the recovery leg be into its drive from behind the body to in front? That is, should there be a notable angle between femurs of the recovery and support leg (with the recovery lagging back behind the body), or should the recovery leg already have started to sweep through, perhaps already moving in front of the body?

I’m thinking only of the first seven to eight steps (roughly ten metres at a quality performance level) and assuming triple extension is a given.

I guess the answer has to do with the athlete’s stride rhythm in the early-going, but what do you all see as best?

What drills can be done to help improve rhythm at the start?