Catch question

So I am still in search of the decent catch. Unfortunately, particularly on my left when I try to pivot my forearm at the elbow (without lowering the upper arm at all), my elbow suddenly drops for a millisecond and my forearm actually gets higher, as if something is pushing my forearm up and medially. Then I regain control and pull back with a high elbow. :confused: I happens so fast that I only see it when I take video, I don't really feel it. I'll post some video when I get home. I can't figure out why it happens. One thing I discovered that seems to help is I lower my whole arm just an inch or so before pivoting at the elbow, and the momentum of this seems to help get that shoulder internally rotated and keep the forearm heading down from the get go. I know this is not the ideal EVF, but I'm wondering if this would be a good start to work with. Does anyone else do this? In some video of Thorpe swimming casually he does this, but in his races he doesn't. Here's a couple examples; YouTube- Ian Thorpe swimming freestyle 1 (casual) YouTube- Ian Thorpe swimming under-side (you see a little of both in this one) YouTube- Ian Thorpe Underwater (right upper arm doesn't seem to drop at all, classic EVF). I'm thinking I should just stick with what I'm capable and build from there rather than struggle with an ideal catch and feel frustration. Trying so hard to get a good catch messes with my breathing as I don't breath relaxed. Any advice is greatly appreciated, I really want to get better. As I said I'll post video later tonight of my ugly catch. I don't have video yet of the adjustment I'm doing, but my son said it looked better. I'll try to post that next week.