The hidden senses
Vestibular and proprioceptive systems
IF YOU IMAGINE the body as a house, then the sensory system is the foundation. It is not visible, but without a solid foundation cracks and problems will occur somewhere else in the house.
The same applies to the human body: without adequate integration of the senses, we will see difficulties with motor coordinating, fine motor skills, social development and visual perception.
There are two lesser-known senses that need attention in order to avoid a poor foundation: the vestibular or movement sense and the proprioceptive (muscle and joint feedback) system.
The vestibular, proprioceptive and tactile systems are key to our development. They work together in providing us with feedback about where our bodies are in space, the rate, speed and force of our movements and what we are feeling from the inside and from the outside in and on our bodies.
Without this information we would be floating around unaware of our movements, and unable to plan and correct movement sequences.
THE VESTIBULAR SYSTEM
The vestibular system is in the inner ear and responds to our head position in space and against gravity. Every time we move our head to look upside down, turn our heads, spin around or tip our head side to side we activate this system. This then sends neurological pathways to our brain to activate different areas and initiate the following areas of functioning: balance, auditory processing, eye movements, postural control and emotional well-being.
Functionally, this system tells us if we are standing or sitting, if we are upright, upside down or leaning. The vestibular system has many interconnections with almost every part of the brain, and therefore effective vestibular processing leads to good integration of the senses, appropriate gross and fine motor coordination and higher order skills such as reading and emotional well-being.
Functionally, we need to understand where we are in space in order to
understand the space around us. This becomes the ability for baby to crawl over, under, through and between items and objects. This sets up the ability to know bigger versus smaller (“I can fit under the table because I am smaller than the table”), which lays the foundation for mathematics.
The ability to plan in space is also important, as navigating your body through space creates depth perception and 3D space, which is the foundation for 2D space, such as working on a page, doing puzzles and building Lego. This system starts developing at around nine weeks in utero. This means that your baby receives movement input from a very early age and benefits from such movement. Often parents are fearful to move their babies once they are born, however a lack of movement can cause issues with sleep, achieving a calm alert state and appropriate gross motor development.
Vestibular activities should be joyful. Some children can however be sensitive to movement. We therefore start with movement close to the mom or dad’s body and then increase to moving away from mom and dad. Look out for the following signs that your baby is not happy with the movement: crying, sweating, increased heart rate, looking away, flushed cheeks. If these happen, stop the movement activity and follow with a big deep hug or massage to calm the sensory systems.
Movement input can either activate and alert babies and toddlers, or it can be used to calm and organise.
THE PROPRIOCEPTIVE SYSTEM
Proprioception refers to sensory information we receive directly from our muscles, joints and skin about our own movement (rate, speed, force and timing) and body position in space. When we receive adequate proprioceptive input into our bodies, we are able to move with more coordination and control. Without effective proprioception in our hands, for example, we would not be able to button our shirt without looking, or to hold a pen with adequate force and control.
In utero, a baby receives proprioceptive input by pushing against the uterine wall, and by being surrounded by fluid. This constant deep pressure allowed for the baby to gain information about their body movements. When a baby is born, they lose this constant deep pressure and we therefore need to provide this to help them remain calm, organised and gain body information. This is one of the reasons we swaddle babies. As a baby grows and develops he will gain proprioceptive through tummy time, crawling, walking and eventually move on to the toddler years of bouncing, jumping and crashing in to everything. When we see toddlers who are uncoordinated, clumsy, bump into things or have decreased balance, we often suspect a proprioceptive difficulty.
Proprioception is used to calm and organise the sensory systems and can therefore be used to calm a baby to sleep, and help them sustain sleep. It is also useful for helping tactile defensive babies as we massage their bodies, and in particular hands and feet, before exposing them to various tactile mediums.
THE TACTILE SYSTEM
The tactile system is the largest sensory system and it plays a vital role in human behaviour, both physical and mental. This system is the first to develop in utero and is fully functional before the visual and auditory systems are just beginning to develop. Therefore, tactile stimulation is important for overall sensory functioning and well-being. Touch is used for protection (temperature and pain) and discrimination (being able to tell the difference between size, weight and texture).
The more tactile experiences our babies have, the more responsive and refined their touch system becomes. There are so many opportunities for learning with touch during everyday events such as bath, play, outings, playing outdoors and mealtimes. As a baby grows and develops she will use her hands for different purposes. Allowing children to explore and experiment with their hands will allow a better foundation for fine motor skills needed for function and learning later on. ● Young babies suck and chew on their hands for comfort. ● They look at and feel their hands as a way to self-soothe and explore their own bodies. ● They eventually learn to grasp and release and can manipulate toys. ● They use their hands for feeding. ● They use their hands and fingers to poke, prod, touch, post, feel and explore in order to learn. ● Eventually they use their hands to dress, write and cut.
For some, tactile input is a scary and
PROPRIOCEPTION IS USED TO CALM AND ORGANISE THE SENSORY SYSTEMS AND CAN THEREFORE BE USED TO CALM A BABY TO SLEEP
unknown experience where they have negative reactions such as fear, gagging, sweating, increased heart rate and therefore avoidance of touch input.
This can be brought on by seemingly familiar and non-threatening touches such as during messy play or even touching their own foods. This condition is known as tactile defensiveness and has an impact on a child’s daily functioning and emotional state.
Tactile sensitivity in the hands is often associated with oral sensory defensiveness, which will impact on a baby’s transitioning to solids and could cause general feeding difficulties.
It is important to support these babies and allow them to go slowly and remain comfortable and at ease.
The proprioceptive system is helpful in decreasing tactile defensiveness and should therefore be used every two hours throughout the day in full body feedback and specific feedback into the hands, such as massage.
Some tips on presenting messy play to children with tactical sensitivity and defensiveness: ✓ Light touch will be alerting while deep touch will be calming. ✓ Rub the child’s hands and feet prior to exposure to tactile input. ✓ Provide exposure to dry textures before wet textures. ✓ As mom, you should stay neutral, or positive, about the experience and not say things such as, “This is gross,” as the child will pick up on this and then be hesitant to try. ✓ When introducing solids, try not to purée food too smoothly and always provide some texture and flavour diversity. Gradually increase the lumpiness of the foods you offer. ✓ Allow baby to play with his or her food while feeding so that it is a fun experience and baby tolerates touch on the hands, which will encourage tolerating it in the mouth.
Our everyday environments and routines should allow for the vestibular, proprioceptive and tactile systems to be activated and therefore integrated. But with fewer breaktimes at school and less free play for younger children, these sensory systems are not being activated enough in the 2010s. The impact from this is felt in everything from sleep and eating to learning and concentration. YB