Someone with vestibular hyposensitivity is typically under-responsive to input from their vestibular system. They often find it difficult to work out which way their head is pointing.
This can be dangerous. For example, for most people, if they feel themselves start to fall, their natural instinct is to put their hands out to protect themselves. However, for someone with a vestibular under-sensitivity, their brains do not get the message that they are falling, at least not in time to respond by putting their hands out to protect themselves. This can result in relatively serious injuries such as concussion, even from a simple trip.
Someone who is hyposensitive to vestibular sensory input is also likely to actively seek additional vestibular sensory input. They may constantly spin or rock, and love to do activities that involve lots of movement.
At the playground they may love swinging very high, or going very fast on the roundabout.
Adults with this sensory difficulty often have a love of extreme sports.
Typically, someone who craves vestibular input will find it very difficult to stay still. This often leads to a diagnosis of Attention Deficit Hyperactivity Disorder (ADHD). While it is certainly possible for someone to have ADHD as well as sensory difficulties, it is important to make a distinction between the two, especially given the likelihood of mis-diagnosis in this case.