Do you think your ds would want to join in on a team if he felt more competent at a team sport? If so, I think I'd handle this by letting him select a sport, and then working with him on repeated tasks that the sport requires so he can learn how to play. A 90th percentile processing speed is not indicative of slow processing - so jmo, but I doubt that's what's holding him up with team sports. I'm guessing there are other kids playing sports who weren't born Auber-coordinated and need repetitive practice to learn skills, which they are most likely getting through playing with other children. I wonder if it's possible the challenges your ds has with social pragmatics might not be playing a part. What's happening on the playground at recess? Is he joining in group games there, or having a tough time fitting in?
You've said that every boy in your area is involved in a team sport. I realize martial arts is an individual sport, but it's an individual sport that people participate in in groups. Is your ds taking martial arts classes with other kids? Are there any students from his school also taking martial arts? If he really loves martial arts, would it be possible to try to organize an after-school club at his school? Is he on a swim team? Just wondering - in our area most of the sports are outside of school at this age, and many times kids make friendships through those sports, and it wouldn't be unusual to find another student from your school participating in the same sport - but that includes individual sports such as martial arts and swimming.
Please know I understand your frustration and how difficult this is for your ds. My ds is extremely uncoordinated (with a disability causing the lack of coordination). Early elementary was the toughest time in terms of fitting in with other kids who were into sports - but for our ds it wasn't just not being coordinated that set up boundaries with the boys who played team sports for fun - he also has an expressive language disorder and difficulties with some aspects of social pragmatics - if he hadn't had those additional challenges, I think it would have been much easier for him to step into a team sport and give try it long enough to develop passable skill at it. What helped him the most in the long term was helping him with his expressive language challenges, while keepingt him in the individual sports when he was really young - he still pursues the individual sports he liked best, and he's picked up on a few more as he's moved into high school. By the time he was in upper elementary he started realizing that not *every* kid was good at team sports, and that there were other students who enjoyed the individual sports he enjoys.
Anyway, those are just my random thoughts -
Best wishes,
polarbear
