Re: Ukemi and Dizziness
my big son (big = 11 years) practices aikido since he was 8 years old, and last year he also had and still has sometimes the dizzines problem, especially when doing too many forward rolls and/ or tai sabakis during the warming-up. No problem during training, apparently the different movements between the rolls impede the dizziness. It comes from repeated rolls.
He went to a doctor who said that it might be some minor parts in his ears (where you have the sense of equilibrium) that might be unsettled, and if he had a break in ukemi during some two or three weeks, they might get into the right place again. But they didn't. Then he went to an ORL specialist, who also could not help him.
He still has it from time to time, and he just cannot make too many repetitive rolls. But for training it's fine.