Re: Problems with Ukemi
Start from a kneeling position, maybe. I do it from standing, but in a very long stance so I'm not very high up, and the force is going more forward, rather than straight down (as it would be if I was standing upright.)
Remember that you've got to be loose, the key is relaxation. I only roll well now because I rolled instinctively from a friend attacking me with a bokken (lol), and I thought "Hey, I CAN do this, I just have to stop being afraid of it." Once you're relaxed, your muscles and limbs all move much more freely, and it's a more natural movement coz everything followseverything :-)
Good luck, you'll get it eventually.