We have been experimenting with a step-hop (or split-step in Tennis) with our passers, and have been encouraging a small hop for both back-row defenders and front-row blockers.
The concept isn’t new by any means, and the general idea is that we are trying to put the muscles in our legs under what’s known as a “stretch-reflex”. It turns out that muscles put under a small load respond faster than those that aren’t under that same load. In other words, by doing the little hop, we react faster than if we didn’t.
The timing of the step-hop for us in serve-receive has been step when the server jumps, and hop when the server makes contact. The timing for blockers is hop when the setter sets the ball, and for back-row defenders to hop when the hitter makes contact.
I have been very pleased with a hop for our blockers and our defenders, but less pleased with a hop for our passers. I don’t know that the ball is coming fast enough to warrant a big step hop on serves (maybe a little hop?), and certainly that need is going to be even less in the women’s game where the ball is moving more slowly. Our problem seems to be that we step hop forward quite a bit, then get jammed by serves that go deep. Ideally we’ll fix this going forward, but I haven’t been excited enough about it to push it out to others in our clinics.
As for “get stopped” and “be simple”, we think those are good principles. But the idea of a hop is also a very good principle, one that is rooted in physiology and bio-mechanics. And the game moves fast enough that it warrants some advancement of our ideas about how to play, and we think the hop is probably an evolutionary step towards playing better volleyball.
As for studies, we haven’t done any, and I don’t know how we would even structure them. Control groups and those kinds of things would be very, very hard to put together and it would require a lot of time and resources. Controlling the variables in a study like that would be extremely difficult, as would coming up with a good measurement system. The only studies we are relying on are those that show the efficiency of the stretch-reflex. Do some Google searches on that, and you’ll come up with a ton of reading material.
I hope this helps.