DS has developmental coordination disorder (and probably motor dysgraphia). We had him tested after a brain injury and one eye was not tracking normally at the time. I don't think he had much in the way of depth perception and he probably had some double vision. What he really bombed was a test called the "Grooved Pegboard" where he was timed and had to put pegs into little holes. His Z-scores were lower than -4 for one hand and -3 for the other. I don't know what the percentile ranking is for Z-scores that low but I think under the 1st percentile. He was at 50th percentile for coding, symbol search was around a 12, and block design was a 13, while matrix reasoning and picture concepts were 18/19. Block design is timed like coding and involves manipulating little blocks (according to the explanation in the report) but he didn't bomb it the way he did for the pegboard test. The neuropsych stated that because of the fine motor aspect, the score is likely an under-estimation of his visual spatial ability. I know that some OT tests involve tasks like the pegboard but you will want to make sure you get one that is timed. Since DS has such good visual spatial ability his score would be really high for the visual motor integration parts of the test (like the BOT-2), raising his composite test score, but in terms of raw motor ability scored alone, he has always been very low. His scores seemed especially terrible after the brain injury, though.
He has been in and out of OT (including school OT) and honestly, I don't know how much it actually helps in terms of increasing motor ability. It seems more helpful in terms of adapting, for instance learning how to hold a pencil correctly, practice with writing letters, etc. Our insurance has always paid part of the cost. I don't think it would be worth it to pay full price out of pocket. It isn't difficult to work on these types of things at home, with a child who will cooperate.
