Why do children love swinging, playing Ring around the Rosie, and otherwise getting dizzy? Because it feels great to their vestibular system! The vestibular system processes the body's relationship to the earth - it tells us if we're falling, leaning forward, or standing perfectly still. The development of this sense results in balanced and coordinated movement through space. Children develop their vestibular senses by swinging, spinning, twirling, and rolling around on the ground. Children gravitate toward these movements naturally. Vestibular movement is in fact considered critical to brain development.
Children with sensory integration disorders might be either hyper- or hypo- responsive to movement. Hyper-responsive children, who overreact to movement, might frequently get car sick or become afraid to put their heads upside down. They may avoid play structures with a lot of unexpected movement (i.e. suspension bridges) or choose to stay on the ground for all their play activities. Children who have hypo-responsive, or low registration of movement, will seek out movement every chance they get. These are the children who are always moving, spinning, fidgeting, and hanging upside down.
Your playspace can provide a variety of vestibular movement opportunities for all children:
(Photo courtesy of eibe)