The problem of balance had never crossed my mind until I had an attack of vertigo a few years ago. It was weird. It felt like being carried by the waves in a chopping sea. I had to hold on to the bed to prevent from being thrown off. But I knew I was lying on a stationary bed.
What is postural balance? What keeps us upright and steady?
Balance is controlled by the nervous system. When we move, stand, walk, jump, turn, etc., a very complex mechanism is in operation which we are not aware of. To keep us in balance while continuing these activities, the body has to coordinate in precision multiple sensory inputs and motor responses.
Three sensory systems take part in collecting information relating to balance:
Vision – The eyes see the surrounding objects and detect changes in space. They sense whether you or your environment is moving.
Imagine watching buildings, trees, cars and people passing by from inside a parked car; then compare this perception with what you see when driving.
Vestibular system – These sense organs are located in the inner ear. They detect equilibrium, motion and spatial orientation. Put simply, it helps to determine if your body is stationary, moving, turning or rotating.
A problem with the vestibular organs can cause vertigo—the sensation of spinning even when you are perfectly still.
Do you have experience on a swing ride at the funfair, or on a ferry crossing the sea?
Somatosensory system – Sensory receptors (proprioceptors) in the skin, muscles and joints detect the spatial position and movement of the body. The sensory input from the neck and ankles are especially important. They determine the direction of the head, the body movement relative to the supporting surface, and positions of different body parts relative to each other.
Without looking, we can tell whether the surface we are standing on is hard or soft, and stationary or moving. By the way, do you have to look at your feet when climbing stairs?
Three parts of the brain are involved in processing these sensory impulses and maintaining balance:
The brain stem is the posterior part of the brain that joins the spinal cord. All nerve connections between the brain and the rest of the body pass through here.
The brain stem receives sensory impulses and pass them to the cerebellum and cortex for further processing. It transmits motor impulses which control movements of the eyes, head, limbs and the rest of the body.
The cerebellum is the coordination centre. It integrates sensory impulses, controls motor activities, and enables us perform voluntary tasks such as dancing and writing. The cerebellum regulates posture, movement and balance.
Patients with damaged cerebellums have difficulty keeping their balance and maintaining proper muscle coordination.
The cerebral cortex plays a key role in memory, attention, perception, cognition, awareness, thought, language, and consciousness. We are aware of ourselves and our surrounding through the cortex. The information and experience stored in the cortex helps the body make voluntary or involuntary actions. That’s why we can maintain balance and have clear vision while moving.
Do you have any issue with your balance?