The inner ear is composed of the semicircular canals, the utricle and the saccule, cochlea, and the vestibulocochlear nerve.  There are three semicircular canals, which function to relay information to the brain and cerebellum about the speed of head movements.  The semicircular canals are filled with fluid, called endolymph.  When the head turns, endolymph flows, which causes tiny hairs in the canal to bend in different directions.  The direction in which the hairs bend, determines how the vestibular nerve is stimulated and consequently what message is sent to the brain about how the head is turning. The brain uses this information to help coordinate the movement of your eyes and head.  If this is not functioning properly, you can develop Cookie Monster googly eyes, or vertigo, and the eyes will not be able to appropriately move with the head.

The utricle and saccule, like the semicircular canals, sense where the head is in space.  They also orient us in relation to gravity.  The saccule senses vertical movement of the head, as in bouncing.  The utricle senses tilting of the head side to side and forwards and backwards.

The vestibulocochlear nerve, the 8th cranial nerve, relays information from the inner ear about our body’s position in space to the brain for interpretation and action.  It takes all information about our head’s position and movement and hearing to the brain and its related structures for interpretation and action.  It helps keep our eyes stabilized and moving in a coordinated manner while our head moves.

The coolest thing about our inner ear is that we have two and they both report back to the nerve about the same head movement.  This is called redundancy and another method in which our nervous system is flexible and adaptable.  So, if one is late to work or out sick, the other one is there to pick up the slack, and we can maintain our sense of equilibrium.

©2012 Geaux to Physical Therapy. All Rights Reserved.

One of the reasons that our risk of falling increases as we age is that our balance declines.  This decline is partly due to age-related changes within the body and partly due to changes in lifestyle.  The best way to avoid the complications associated with falls is prevention.  The good news is you can improve your balance and decrease your risk of falling by performing a few simple exercises.  In physical therapy I use a variety of activities to reduce someone’s falls risk including stretching, aerobic conditioning, strengthening, and balance tasks.  The company I work for, HealthReach Rehab, offers specialized programs including falls evaluations and safe home evaluations.

Our balance and ability to stay upright is generally controlled by three things: vision, the inner ear, and the musculoskeletal system.  If there are problems with any of these systems, our balance can decline.  Some people rely heavily on their vision to maintain their balance and as vision becomes impaired, balance can be significantly affected.  You can try a simple test (if safely able): try to stand on one foot then close your eyes.  The task gets harder.  For those who really rely on their vision for balance, staying upright when their eyes are closed is not possible.  How does this relate to everyday life?  Ever get up in the middle of the night for the bathroom?  Had to walk in a dimly lit movie theatre?  Walk outside at night?  Our inner ear and musculoskeletal system need to be strong to compensate in these conditions.

Risk Factors for Balance Impairments and Falls
•    Impaired vision
•    Muscle weakness
•    Inflexibility
•    Decreased endurance
•    Inner ear dysfunction or history of inner ear dysfunction
•    Dizziness or lightheadedness
•    Certain medications

Tips to prevent falls
1.    Stay physically active and include balance exercises in your routine.
2.    Have your vision checked yearly and update your prescription as needed.
3.    Discuss your medication list with your doctor or pharmacist for interactions that may cause balance impairments.
4.    Make your home safer by clearing clutter, loose wires, and ensuring adequate lighting throughout your living spaces.

A good website to check out is the Fall Prevention Center of Excellence’s.  There are lots of resources on identifying whether you or a loved one is at risk for falling and information on options for lowering that risk including fall-proofing the home.

Even if you feel like you have relatively good balance and your vision and inner ear are functioning normally, you can still be at risk for losing your balance if your muscles are weak, tire easily, or have lost flexibility.  If you are experiencing a feeling of unsteadiness, loss of balance, or have fallen recently, talk to your doctor and ask about treatment options including physical therapy.

Resources

Fall Prevention Center of Excellence http://www.stopfalls.org/

©2012 Geaux to Physical Therapy. All Rights Reserved.