Movement and Body Awareness

Problems with the vestibular system

How the Body Handles Movement: Vestibular Sensitivities
The vestibular system has many different pathways and different jobs to accomplish. As with other sensory systems, some of these pathways may be working efficiently, while others are not working well at all. The difference between children who are oversensitive and undersensitive to movement can be dramatic. The brain normally processes vestibular and other sensations by facilitating protective responses if they are appropriate ("Watch out!") and inhibiting protective responses ("No need to worry – go for it!") or at least dampening them ("Proceed with caution") if there is no immediate threat. A child will typically assess the situation – Am I in danger? – and act accordingly. Not so for the child with a poorly functioning vestibular system.

Gravitational insecurity. A child with gravitational insecurity has an exaggerated emotional response to antigravity movements way out of proportion with the actual possibility of falling. The pull of gravity most of us trust and take for granted is perceived by this child as a primal threat to survival. Because there is no inner sense of gravity's reliability, just a bit of movement may feel like he's bungee jumping or being tossed into outer space. Research suggests that gravitational insecurity may be caused by poor modulation of input from the otoliths.1 The gravitationally insecure child prefers to stay low to the ground – lying down or seated (often in W-sitting, see page 176 for an illustration) – rigidly fixing his body to prevent any possibility of movement, and avoiding most active physical tasks. This child becomes quite upset when movement is forced on him, especially if it is unexpected.

Max, the little boy afraid to get on the swings, is a classic example. He becomes fearful and anxious whenever his feet aren't firmly planted on the ground. He hates it when other people force him to move, but he pretty much trusts his mom. Other parents and baby-sitters in the playground are envious about how he never runs off like their children do. Instead, Max sticks right by his mom's side, looking for her to fend off all those kids who might bump into him or push him. He waits for her to recognize that he can't handle all the chaos and to safely guide him to the security of the sandbox where he can plop down in a corner, close to the earth.

Movement intolerance. Some children feel uncomfortable with fast movement or spinning. Children with vestibular sensitivity get dizzy or nauseated very quickly on merry-go-rounds or riding in a car. For children who also have visual sensitivity, just watching another child spin can make them sick because an eye reflex stimulates the vestibular system. A child may have both gravitational insecurity and movement intolerance.

Hyposensitivity to movement. When a child has a high threshold for sensory stimulation, she craves more, and more, and more of it to get the input she needs. A child who underresponds to vestibular stimulation may move a lot, but not necessarily in an organized, appropriate manner. She may have low muscle tone and difficulty moving against gravity. She may have difficulty transitioning from one position to another (such as getting up to walk), and problems starting and stopping movement. She may also move impulsively, without regard to safety.