Where is the vestibular system located?
The vestibular system itself is located in the part of our inner ear called the vestibule, this is how it gets its name. The vestibule is attached to the cochlea, the part of the inner ear that helps with hearing. Inside the vestibule, there are two organs, the semi-circular canals, and the otoliths.
How does it work?
The vestibular system receives information when our head moves. Our head can move up and down (e.g. nodding yes), side to side (e.g. nodding no). We can also move our ear down towards our shoulder. With the help of our body, the head also moves forward and backward, side to side, and up and down. Essentially, our head moves in all possible directions. This movement gives information to our vestibular system, which helps our brain to know where we are in space and how fast or slow we are moving.
How the vestibular system helps day to day
Balance and the vestibular sense
Balance is essential for all of our movement. Without balance we would not be able to roll over, sit up or walk. We rely heavily on the feedback from our inner ear to make sure we don’t fall over if the ground is uneven or when there are steps. We can also keep our bodies steady if the surface underneath us moves, for example on escalators. When we roll over in bed, it is our vestibular system that makes sure we don’t roll out! Majority of the body movements we make rely on good balance and postural control.
Postural control is all of the small adjustments our body is constantly making to ensure it doesn’t over or under balance. Our postural control allows our bodies to move in different directions whilst remaining stable. For example, when we bend forward our back muscles and our stomach muscles work together to make sure we don’t go too slowly, or crash down too quickly, or fall over. When we throw a ball we can move our arm without our whole body going forward with it and without losing our footing.
Reaching across the table to get the salt, also requires good postural control. Without it, we might fall out of our chair into the person next to us or into our food. We can twist and turn and bend our bodies in any number of ways without falling over when our vestibular system is working well.
Muscle tone refers to the constant little contractions our muscles are making when we are still. These little contractions allows our bodies to increase or decrease tension as required when we are still and moving. Our vestibular system supports this tension. Muscle tone can be affected by diseases that damage the brain, such as a stroke, head injury or cerebral palsy. In these cases, muscle tone might be very tight or very low and this makes movement much more difficult. Some children with Sensory Processing Disorder might have lower than average muscle tone and this can affect their postural control and stability.
Spatial orientation lets our brain know where our body is in space. It helps us to know if we we lying down or standing up or sitting. Or, if we moving forwards, backwards. sideways, up or down. It also gives feedback to let us know how fast are we moving.
This would include examples like. Are we high off the ground on a ladder or are our feet on the ground? Is there an incline or are we on the flat? Our vestibular system is constantly sending this type of information to our brains to let us know where we are in space.
Alertness relates to our ability to pay attention. Surprisingly, our vestibular system plays a big role is our attention and focus. Typically, if you have been for a run or been exercising you will be more alert and focused. This is because of the extra vestibular input your brain has received from the movement. If you have spent the entire day seated, you are more likely to feel a bit more sluggish.
Eye movements and the vestibular sense
Finally, our vestibular system controls our eye movements. It allows us to look in the direction we want to look. We can look up to the board or teacher and then back to our work. Or look over at the clock and then back to our TV, without getting dizzy or losing focus. When we walk, what we see doesn’t bounce up and down, it stays focused. Our brain is constantly processing the information about our head movements to adjust our eye movement to match.