Trip. Fall. Boom

What is Balance?

According to Neurological Rehabilitation¹, “balance is a complex process involving the reception and integration of sensory inputs and the planning and execution of movement to achieve a goal requiring upright posture.  It is the ability to control the center of gravity (COG) over the base of support in a given sensory environment.”

The short answer: Balance is the body’s attempt to keep us upright. 

What goes into balance?

Balance is made up of three primary components: vision, vestibular system and somatosensation/proprioception.  The figure below is a pictorial representation of the components of balance. 

These are some the variables affection balance:

•         Location of the COG
•         Base of Support
•         Limit of stability – strength of key balance muscles – back, calf, gluteals
•         Surface conditions – standing on smooth floor, grass, rocks, foam
•        Visual environment – stationary, moving environment, in dark,
•        Intentions and task choices – what you want to do

1.  The Vestibular System:  Complex mechanism in the inner ear that controls balance by monitoring the position of your head.

2.  The Visual System:  Uses input from your eyes to detect the changes in the floor surface and where your body is in space.

3.  The Somatosensory/Proprioception System:  Uses sensory input from your extremities to give your brain feedback about the surface you are standing on and where your body is in space.

How do these systems affect your balance? 

An inner ear disturbance, such as an infection, causes your body to react incorrectly when your head position changes.  This can present as dizziness or a feeling of feeling “wobbly” during movement.

A visual impairment might cause difficulty detecting changes in the ground surfaces, especially during low light situations, such as going to the bathroom in the middle of the night or walking in a dark area such as a movie theater.

Sensation problems in the feet and lower body, such as neuropathy or abnormal tone, can inhibit accurate feedback to your brain about the ground surface and your body in space.

Why is this important and can physical therapy help?

Knowing which of these 3 systems might be impaired can help physical therapists set up the plan of care.  For example, a patient who has diabetic neuropathy or abnormal tone in his/her feet or lower body relies heavily on the vestibular and vision systems to maintain balance.  It would be important for this patient to know that he/she needs well-lit areas to be safe.  This will reduce the risk for falling.

Understanding the 3 systems also helps physical therapists improve balance.  One way to improve balance is to improve the function of the impaired system.  There are specific techniques to improve vestibular function and proprioception/balance training can improve lower extremity feedback.  

Another way to improve balance is by compensating to enhance the function of the systems already working well.  For example, proprioception activities, such as standing on one leg or standing with eyes closed, can teach the body to rely more on sensory feedback from the legs.  This can be very helpful in a patient who has difficulty with vision.

Training Ideas

•             Body Position: Though we often think of standing when it comes to balance a growing child utilizes many more positions than standing aone. Incorporate those developmental positions into your balance program such as laying (on back, side, or belly), quadruped/crawling, sitting, kneeling/half kneeling, as well as standing. Practice working in and transitioning to/from these positions. This is also great functional mobility work.
•          Points of Contact: The more points of contact or the greater the surface area touching the floor the more stable you will be and as you decrease points of contact the greater the challenge to your balance. When practicing consider decreasing the points of contact as the child progresses (start with 2 hand held assist, move to 1 hand then 1 finger for support, then no external support).
•        Degrees of Freedom: Similar to “points of contact” the more degrees of freedom, or places the body can move, the great the challenge for balancing.  Some children, especially the child with considerable hypotonia (low muscle tone) may need external help from orthoses to limit the degrees of freedom.  PT’s may recommend foot orthoses (FOs) or supramalleolar orthoses (SMOs) to help with development and progression of balance and gross motor development.
•         Head Position: Looking straight ahead is the easiest for your balance but once you change head position by looking up/down, turning left/right, or tilting left/right you increase the balance challenge as your body works to maintain its sense of upright
•        Sight: When eyes are open in a well-lit environment balancing is at it’s easiest but if the lights are dimmed, the area is dark, or you close your eyes balance becomes significantly more challenging as your body loses a key tool in reacting to the environment around it as well as maintaining upright.  To help train balance, PTs can and will often change the lighting or have a child close their eyes during a task to help train the other components of balance. 
•         Surface: A solid, smooth surface poses the least amount of challenge to balance but by making surfaces soft, slanted, un-level, rough, asymmetrical, or mobile the degree of difficulty increases exponentially. Foam pads, bubble wrap, grass, standing on a wedge, and wobble boards are great tools to help train balance and strengthen important muscles required for good balance (extensors, gluteals, hip stabilizers, gastroc/soleus)
•        Stance: A normal or wider base of support is much easier on balance than a narrow base of support.  You can also change position by doing a split/staggered stance or having your points of contact be in a turned in or turned out position which modify your balance reactions. Single leg stance and tandem stance are great ways to train static balance.  For children, another important dynamic stance would be kicking a ball which requires brief, mobile single leg stance. 
•         Movement: There is a level of simplicity with staying stationary or immobile but when you add in movement, especially tri-planar or diagonal/PNF, your balance is stimulated by the dynamic and unpredictable inputs you give the body. Changing from static balance to dynamic balance is a good way to progress the training.  Adding mobility could be kicking a ball, hopping on 1 leg, moving upper body while standing on 1 leg (playing basketball while standing on 1 leg or standing on wedge/foam)

How can a PT test or assess balance in children?

There are a multitude of balance tests, testing different types of balance : quiet standing (romberg, single leg stance, postural sway), active standing (functional reach), sensory manipulation (sensory organization test, CTSIB), vestibular (oculomotor tests, nystagmus), functional scales (BBS, TUG, DGI), Combination test batteries (Fugl-Meyer), dual task (walkie-talkie, multiple tasks test)

For children, PTs especially need to take into account functional balance – walking on balance beam, single leg stance, kicking a ball, walking on line, etc.  These are critical gross motor activities kids should be doing.  The BOT-2, for example, takes this developmental/functional balance into account

BOT-2:

Author: Robert Bruininks, ----Oseretsky

Purpose: Developmental motor skills

Age Range: 4.5 –14.5 years

Areas Tested: Balance, strength, coordination, running speed and agility, upper limb coordination (ball skills), dexterity, fine motor control, visual-motor

Berg Balance Scale (BBS)²:

Purpose: Measures balance during movement activities

Age Range: 5 years and older

Areas Tested: 14 items including common movement activities such as picking an object up from the floor, walking and turning.

The BBS has begun to be used for children, but true reliability and validity has not been established.  The APTA Section on Pediatrics has included BBS on its official assessment tool list. 

Pediatric Balance Scale³:  This is a modified version of BBS.  PBS has been show to have good test-retest and inter-rater reliability for school-aged children with mild to moderate motor impairment. 

FUNCTIONAL REACH TEST (FRT)

Purpose: Measure of anticipatory standing balance when reaching

Age Range: 4 years and older

Areas Tested: Measurement of the distance that the child can reach forward from a stationary standing position

PEDIATRIC CLINICAL TEST OF SENSORY INTERACTION FOR BALANCE (P-CTSIB)

Authors: Crowe, Luyt, Westcott,

Purpose: Measures sensory system effects on stationary standing postural control (balance)

Age Range: 4-10 years

Areas Tested: Six conditions: Standing on floor with eyes open, eyes closed, and with dome (eyes open, but vision stabilized); Standing on foam with eyes open, eyes closed, and with dome (eyes open, but vision stabilized)

TIMED UP AND GO (TUG)

Purpose: Measure of anticipatory standing balance & gait control, motor function through a typical activity

Age Range: 4 years and older

Purpose: Measurement of the time it takes to rise from a chair, walk 3 meters, turn around and return to a seated position in the chair.

***Please note this is NOT a comprehensive list of assessment tools.  There are many other standardized tests and measures for balance, and there are many tasks that can be timed or measured to use as assessment tools.

         

Resources:

1.  Umphred D. Neurological Rehabilitation. 5^th edition.

2. Kembhari G, et al. “Using Berg Balance Scale to Distinguish Balance Abilities in Children with Cerebral Palsy.” Pediatric Physical Therapy. Vol 14, Issue 2, pp 92-99.

3.  Franjoine M, Gunterh J, and Taylor M. “Pediatric Balance Scale: A Modified Version of Berg Balance Scale for the School-Aged Child with Mild to Moderate Motor Impairments.” Pediatric Physical Therapy.  Vol 15, Issue 2, pp 114-128. 

***More to come later on other balance, vision and exercise options!***