How much does a good kick contribute?

Originally posted by Paul Smith Here's the deal folks...forget about weights...if you REALLY want to make a significant break through in your swimming relative to competition stop swimming for 4-8 weeks and go to kick only workouts...as you ease back into swimming you will have the opportunity to "learn" how to integrate a new and powerful element to your stroke...something that 90% of the swimmers I see competing do not do well.... This really caught my attention. I seem to have been hearing this a lot lately: people coming back after a shoulder op, doing kick only workouts and then having their best seasons ever. I don't doubt the authenticity of it either. I am just interested on what is actually going on. Why should this be the case? Has anyone ever scientifically measured the amount the kick contributes to forward propulsion? I mean ratio wise, compared to the arms, what would it be? 80% arms : 20% legs? What about the swimmers who are great kickers in workouts but can't translate it into faster swimming? How do we actually integrate the kick into our swimming so that it becomes a new and powerful element to our stroke as Paul suggests? Would it be fair to say that a big part of the improvement these (post op/ focus on kicking )swimmers achieve can be attributed to the strengthened core which is a result of the additional kicking. In other words more credit given to the strengthened core than increased forward propulsion. I don't know. I just throw out these ideas for discussion. Syd