When parents come to me for help with their children’s difficulties, very often, a vestibular processing difficulty is part of the problem. Not surprisingly, this revelation is met with a little bafflement – what, after all is the vestibular system?
This week I’ve been inspired to share some insights into this amazing and relatively unknown system. In this podcast I explain:
- What the vestibular system is and how it works
- Why it’s important – the links to everyday functions we take for granted
- How difficulties arise
- Signs of vestibular processing difficulties
- How to make the most of the vestibular system
- Some simple things to do if you suspect a problem
What Is The Vestibular System & How Does It Work?
The vestibular sense is in constant use along with every other sense we have and is part of most things that we do. In fact, it is one of our most influential systems impacting everything from breathing to digestion, fine to gross motor co-ordination, visual control, spatial orientation, regulation of alertness and mood, respiration and overall smooth muscle activity…
The amazing thing is that this mighty system has such small receptors in the inner ear – overall about the size of a pea in each ear. Every time the head moves in space, the vestibular system is activated. The speed, direction, predictability and force of movement affects the degree to which the system is affected.
The construction of the vestibular apparatus is incredible – it looks a little like a crazy pretzel with a couple of important small additions – the loops of “the pretzel” are the semicircular canals that pick up circular movement of the head and influence eye muscles. The utricle and saccule are the ball-like structures that pick up on linear movements in response to gravity. The tail of the system is the cochlear that processes sound.
That last bit might surprise you – the fact is that with the vestibular system you get two for one – it is actually the auditory-vestibular system. The cochlear processes higher frequency vibrations (sound) and the vestibular system processes lower frequency sounds (vibration/movement), and the link between the two means that the vestibular system can prompt the postural muscles to alert to sounds in the environment by making the body more upright. In this position it’s easier to locate and process the source of the sound which can be very important for survival! (Just watch someone reacting to a sudden sound and you’ll see this in action).
Why Is The Vestibular System Important?
This intertwining of senses helps us develop an internal sense of space, time and rhythm – this is important for performing all kinds of actions in sequence, smoothly and efficiently. Children with auditory-vestibular difficulties have problems with:
- Eye muscle control
- Visual perception
Another important interaction is with the eyes. When the vestibular system is working well, it guides postural control, providing a solid basis for independent and mature eye movements – much like a tripod acts as a support for a camera – so the eyes can provide a stable and reliable image to the retina and in turn to the brain. When there are problems with this partnership a child has difficulties with:
- Copying from the board
- Scanning for reading
- And Ball skills
So messages about movement of the head through space are sent form the inner ears to the brain about its direction and speed. This is then filtered through multiple sensory connections to assist in helping your child to keep their balance whether still or moving. In cooperation with yet another sense – proprioception (joint movement awareness, the vestibular system prepares your child’s body for movement.
Activities that involve movement of the head can have a powerful effect on the human nervous system because they trigger the vestibular system – the effects felt varies with the force and directions of the movement, and the child’s sensitivity to it.
Typically, slow rhythmical and sustained straight movements calm children down. Fast irregular movements are alerting, causing children to become more alert, excited and/or active.
The growing child naturally seeks out vestibular stimulation through rolling bouncing (as in cribs or on beds, crawling, walking running climbing, swinging and twirling in circles, learning all the while how to judge space, time and rhythm of movement – gradually increasing the levels of complexity of co-ordination, spatial and body awareness.
As we’ve discussed before, while the link between the vestibular system and co-ordination is well established, growing research is showing a link between movements that activate the vestibular system and improved working memory, and academic outcomes.
So in normal development, it’s important to provide a lot of opportunities to move in age appropriate ways as early as possible. For babies this means floor time and more floor time!! Please no Jolly Jumpers or Walkers (that you sit in).
From the time children are up and walking on two feet, encourage them to climb and swing even if it’s for short periods (1-2 swings) at first – persist gently. Make it a goal to spend at least 10-15 minutes on lively physical play in ways and places you consider safe for your child. Vary it by exploring different parks in your town or city. Whatever you do, don’t let your child sit still for long periods – keep activating that vestibular system on a regular basis as much as possible – and if they resist, then explore the reasons why…
Children who’ve had repeated ear infections, allergies, head injuries or high fevers or long periods of inactivity are more likely to experience challenges with poor vestibular processing.
When There’s A Problem With Vestibular Processing…
When vestibular processing is disturbed or inadequate a child may be either very sensitive to movement or under-sensitive to it.
Children who are highly sensitive to movement (vestibular hypersensitive) will:
- Avoid or limit their exposure to it – as babies they don’t like to roll, they may be slow to develop gross motor milestones, and don’t like moving playground equipment, fast rides or sometimes even going in the car
- Be controlling of movement experiences – they feel the need to be in charge of their movement experiences, and may be OK as long as their feet are on the ground
- Be more likely to suffer motion sickness
- They are often distressed by going in the pool unless their feet can touch the floor and even then can be nervous about being knocked over
- Prefer quiet indoor play and tend to direct others from a stationary position!
It is never wise to “push it” with a child who has gravitational insecurity (vestibular hypersensitivity). These children need lots of support, literally, to explore movement. Low hung swings, glider bikes, soft surfaces and slow and steady is the way to go – with a great deal of patience!
Children who are under-sensitive(hyposensitive) are another story altogether! These live wires can be:
- In constant motion, seeking to satisfy that inner drive to orient themselves in space in order to concentrate
- Poor spatial awareness and difficulties with timing mean they take big risks with movement – climbing too high, going too fast and as a result, need a lot of supervision!!
It’s tempting to read high activity kids as being movement seekers who need movement to organize and to give them more – but this isn’t always true. Sometimes movement seekers are doing so for other reasons entirely, to deal with other movement or sensory issues, and providing additional movement may not only not be effective in helping them organize but actually be disorganizing. I have quite a few children in my caseload who love the trampoline, but the trampoline doesn’t love them! Because they can’t sustain rhythmic movement and are easily “overexcited”l, bouncing on a trampoline (or jumping castle) actually makes so excited it’s difficult to settle even with help.
When we look at seeking behaviours, we need to consider them in light of all of a child’s sensory processing, movement and behavioural regulation skills before we decide what it means and what to do about it.
Having said that – these children can often do well with Move N Sit or Disco Sit cushions, gym ball chairs or those lovely funky new moving seats when working in a classroom. My rule of thumb is if it doesn’t work the first time you try it – it’s probably not going to, and sometimes, depending on the temperament of the child, they can more of a distraction than a help – so each situation has to be assessed on its own merits.
Now if you have a child who you suspect might have vestibular processing issues, the best thing to do is to to seek an assessment by an OT trained in sensory processing. Additionally, if they have allergies or ear infections, a review by their family doctor is important as that can be distorting sensory information processing by the auditory-vestibular system.