A look at our anatomy and how we keep ourselves in balance
The function of balance for us humans is imperative and often something taken for granted. If our balance is impaired we may obviously become unstable but symptoms that accompany the unsteadiness can include dizziness, vertigo, hearing and vision problems, and difficulty with concentration and memory. If we understand the connection we can perhaps learn to understand the cause when something is literally off kilter.
How does our balance work?
Maintaining a centring via our body’s means of support will allow us to be able to see whilst in motion, recognise orientation, gravity, direction, speed, spacial awareness and ensure that we can adjust our posture to achieve stability accordingly by encompassing all such variables.
To be able to do this we utilise complex sensory input systems including sight (vision), touch (proprioception), motion, equilibrium, spatial orientation (vestibular system); all of which work together to motor output to the eyes and body muscles.
In order to maintain our balance we rely on the information delivered by the eyes, muscles and joints, and vestibular organs (inner ear) to the brain in the form of nerve impulses from nerve endings called sensory receptors. If any of these messages are not relayed correctly then our balance may be compromised. Injuries, drugs, diseases, psychological factors, or simply ageing can affect any of these components and therefore our balance.
The reason we take our balance for granted is that our senses do such an efficient job of allowing us to recognise and navigate our surroundings that we barely notice until something goes awry. Our eyes send impulses to the brain that provide visual cues identifying how a person is oriented relative to other objects. Touch informs by way of the skin, muscles, and joints involving sensory receptors that are sensitive to stretch or pressure in the surrounding tissues.
For example, increased pressure is felt in the front part of the soles of the feet when a standing person leans forward. With any movement of the legs, arms, and other body parts, sensory receptors respond by sending impulses to the brain. Along with other information, these stretch and pressure cues help our brain determine where our body is in space.
The neck and ankles are especially important in our spacial awareness as they indicate which way our head and body is facing respectively. The ankles also transmit important information about the surface we are standing on; cues from our movement or sway indicate whether the ground is hard, soft, or uneven for example.
The vestibular system, or inner ear, provides the information relating to our spacial orientation, motion and equilibrium by detecting gravity – our vertical orientation – and linear movement. This is achieved by the fluid within the ear which indicates rotation, direction, and position by way of inertia; when the fluid touches on particular sensory receptors within the vestibular canals these send impulses to the brain about movement from the specific canal that is stimulated.
When the vestibular organs on both sides of the head are functioning properly, they send symmetrical impulses to the brain; if they don’t we are off balance! Once all these messages reach the brain they get sorted and applied to stored information which gives way to us performing automatic movements based on previous learning and memory of repeated exposure to certain motions. For example, contributions from the cerebral cortex include previously learned information; because we ‘know’ that icy walkways are slippery, one is required to use a different pattern of movement in order to safely navigate them, our mind and body work in unison to ensure that we manage this effectively.
How do we learn balance?
As with a baby learning to walk we learn by practice and repetition, in scientific terms a new pathway is formed in the brain by way of the sensory receptors repeatedly sending similar messages and then out again to the muscles. The messages get delivered through this new pathway faster each time until they become almost automatic and the path is established; this process is called facilitation. Even complex movements can become automatic over time but they need to be practiced continuously and effectively in order to do so. This system can even help to repair your balance if one of the sensory inputs is damaged or not functioning correctly, as the pathway allows for adaptation due to learning. Our body is just incredible!
How do we lose our balance?
If any of the input we have talked about is conflicting; like when you’re waiting on a train at a station and another one is alongside and begins to move, we find it hard to decipher whether it is our train or the other that is in motion, this causes us to feel disorientated.
What we are seeing indicates movement yet our proprioceptive, or touch, information from our joints and muscles says otherwise. At this point our vestibular (inner ear) organs may assist in overriding the conflict plus our learned memories and experience can trigger a response encouraging us to decipher the situation by looking around us and seeking visual confirmation as to whether our train is in motion or not. In this instance the situation is resolved.
As we age, or if we have a disruption to any of our sensory inputs, symptoms may arise such as dizziness and vertigo. It may be difficult to walk without falling. Other symptoms include:
• blurred vision
• nausea and vomiting
• mental confusion or disorientation
• feelings of depression, fear, or anxiety
• blood pressure and heart rate changes
• infections of your ear
• head injury
• chemical imbalance in your brain
• Vertigo causes dizziness when you move your head. The symptoms usually occur when you look behind you or look up to reach for an item positioned above your head.
• Inner ear infection or inflammation can make you feel dizzy and unsteady. The flu or an upper respiratory infection can cause this condition.
• Meniere’s disease changes the volume of fluid in your ear, causing balance problems, hearing loss, and ringing in your ears. Its cause is unknown.
• Head injury, strenuous physical activity, ear infections, and atmospheric pressure changes can cause inner ear fluid to leak into your middle ear. This can cause balance problems.
• Sea travel can cause balance problems that may take hours, days, or months to clear up.
• A tumour, such as an acoustic neuroma, can also cause balance problems.
Due to the complexity of the human balance system it can be challenging to be able to diagnose and pinpoint the exact cause of imbalance. That delicate combination of information obtained through the sensory systems means that disorders affecting an individual system could be limitless in variations. The vestibular organs in particular are extra challenging due to their interaction with cognitive functioning or learning and memory, and the degree of influence it has on the control of eye movements and posture.
It is an incredible system which, before now, I too had taken for granted. It is important that we get to know our bodily systems and understand who, why and how we are – I for one feel more balanced just knowing how I achieve it!
References: the Vestibular Disorders Association, with contributions by Mary Ann Watson, MA, and F. Owen Black, MD, FACS, and Matthew Crowson, MD. William A. Morrison MD for Healthline.
This content was originally published here.