Unfortunately in Ultimate Frisbee collisions are possible despite Ultimate Frisbee being a non-contact sport. Above is a link to concussion training. The training is required for all coaches, and provides very useful information about concussions. Parents are not required to perform the training, but having the information as a parent can be invaluable in case the coaches miss something. If you have the time please run through the training above and if you have any questions feel free to let me know.