The balance system

The sense organ of the vestibular system is located in the inner ear and consists of two main parts:

• 3 semicircular canals filled with liquid, at right angles in relation to each other
• The utricle and the saccule, also filled with liquid

Both groups of organs contain hair cells. Any movement of the body, particularly of the head, moves the liquid in the semicircular canals, in the utricle and the saccule, and this way stimulates the hair cells. The movement of the hair in the hair cells triggers nerve impulses, which provide the brain with information on the direction of movement (forward, sideways, upward, downward), its angle (turns, leaning) and its degree. This enables the execution of the appropriate corrective muscle movements. Certain hair cells are extremely sensitive to gravity; they inform the brain of any deviation from the vertical position of the head. The signals coming from the equilibrium system pass through the nerves and arrive at the cerebellum.

The cerebellum receives a lot of information about the movement of the organism, and based on that, monitors the spatial location and body posture (whether we stand, sit or run, etc.) as well as controls all movement.  In the first months of life the equilibrium system must learn how to effectively work together with other senses (touch, motion detection, sight, and hearing).

• The information obtained by way of touching helps to identify surface properties (e.g. whether the movement takes place on sand, concrete, or in water).
• The perception of body movement (kinesthesia) provides information on the movements of muscles and joints.
• Hearing helps us judge the direction, speed and timing of movement (e.g. I can hear that something happened behind my back and I immediately turn around)
• The connection between the balance system and visual system can be observed in the following example: when we spin round, a distinctive eye movement is a sign that the nervous system is trying to scan the environment to compensate for the feeling of dizziness; the sight also helps identify obstacles, persons, objects and the environment.
• The evolution of the sense of balance takes place already in the womb, while the development begins immediately after birth, such as when the mother is cradling her child. The gradual development of this sense allows the child to turn from the back onto the stomach, to sit up, to stand up and finally to walk. The development of sense of balance is completed at approx. 6-7 years of age.
• Small children at 1-10 years of age look for a form of exercise that highly stimulates the balance center (e.g. a swing, a rocking horse, a carousel, a bike, etc.).
• While swinging, the child playfully alternates their balance, casually, without any effort, and the whole process is pleasant, arousing a wish for endless repetitions.
• Constant jumping is not a useless, annoying act, since this way the child develops the movement control system and its strength, as well as the balance adjustment ability.

Signs of malfunction:

• Balance disorder
• Delays in postural reflexes and movements which prevent the achievement of developmental milestones, such as control over holding head up, over sitting, climbing, walking
• Decreased muscle tone
• Aversion to heights, to swinging, the carousel, the escalator
• Inclination to getting lost, to poor orientation
• Clumsiness
• It is difficult for the child to remain calm, s/he is active searching for stimuli such as excessive rotation and swinging
• Spatial perception difficulties
• It is difficult for the child to find out how to operate something, for instance whether to press or drag something
• Tiredness / apathy
• The child is not able to mentally rotate or flip objects in space.