Understanding how sensory input and sensory processing affect a student's ability in the school environment paints a picture that doesn't fit into the the classroom environment at all. Some classrooms are decorated to the teachers taste, hobbies & inspirations and not with a child in mind. Others classrooms are covered with clutter, and only one or two that take children into consideration.
With the new technology age, I see many teachers that simply let the child plug into their I-Pod and shut out the classroom environment. Many students complain that if they can't listen to music, they can't learn. It's true that classrooms can be a sensory overload, but having a controlled learning environment is what the teacher should create and have fun doing it.
Taking time out from the three R's and doing movement activities is a great idea! I have even suggested adding stand up desks to help give the students a way to stretch while in class, and it worked. I have seen yoga balls instead of chairs for those students that need the vestibular stimulation. It's sad, I believe some teachers don't want to take the time to create a good learning environment let alone taking the time to think of how sensory input and sensory processing affects the student's ability to be successful in the school environment.