Part 1 - Motivation Balance

Question 1

Name 3 reasons to learn about balance disorders

Answer 1

• they affect 30% of people before age 65
• 40% of those over 70 report a significant fall per year
• 66% of patients with balance disorders will develop a psychiatric disturbance
• half of people seen in primary care receive no diagnosis for their dizziness

Question 2

Is it within our scope to provide assessment, treatment, rehab, and consultation services for vestibular function?

Answer 2

Yes

Question 3

What is balance?

Answer 3

• an even distribution of weight enabling someone or something to remain upright and steady
• the ability to maintain the centre of gravity (COG) within the base of support (BOS)

Question 4

What term can be described as “where the sum of all forces and force movements acting on the body is zero”?

Answer 4

Centre of Gravity (COG)

Question 5

Where is the COG on a human?

Answer 5

Anterior to the 2nd sacral vertebra (~55% of height from the feet)
- can be located outside the body when active

Question 6

Describe the BOS

Answer 6

Base of Support - the area beneath an object or person that includes every point of contact that the object/person makes with the supporting surface
- the area between our feet, including the feet

Question 7

What is the line of gravity?

Answer 7

An imaginary vertical line passing through the COG to a point in the BOS

Question 8

Why do we have a narrowed BOS when walking?

Answer 8

Because the feet come together towards the midline, so the heel-to-heel (H-H) distance will decrease, and the toe-to-midline (TM-R/L) will decrease, leading to a decrease in balance

Question 9

When walking, what moves first: the BOS or COG?

Answer 9

COG

Question 10

A position or attitude of the body is known as:

Answer 10

Posture

Question 11

Why does good posture usually result in the least amount of energy expended?

Answer 11

• maintains upright alignment
• adds efficiency to specific movement patterns
• allows joints to be loaded symmetrically by decreasing or distributing loads on ligaments, muscles, and bones

Question 12

Postural control occurs with strategies which may be either ______ or _______, and may involve a fixed support or change-in-support

Answer 12

predictive or reactive

Question 13

What are “limits of stability” or LOS?

Answer 13

The distance in any direction a subject can lean away from midline without needing to alter the BOS

• depend on firmness of BOS and strength & speed of muscular responses
• approximately 8 degrees to the front and sides, and 4 degrees to the back

Question 14

T/F: Stability is influenced by the goal/task, central set, environmental organization, motor coordination, sensory organization, and sensory/motor integration

Answer 14

True

Question 15

What is a central set?

Answer 15

Our brain, which writes “motor program” to allow us to hold certain postures

Question 16

What are regulatory and non-regulatory features of the environment?

Answer 16

Regulatory features include all aspects necessary for successful performance of the task (e.g. firmness, texture, rail for balance, etc.)

Non-regulatory features are environmental aspects that are present, maybe even distracting, but not integral to the performance of the task (e.g. sound, people, etc)

Question 17

Regarding sensory organization, what 3 types of external inputs do our brains need to maintain stability?

Answer 17

1) Somatosensory
2) Visual
3) Vestibular

Question 18

Give one example of a sensory disconnect that could cause dizziness?

Answer 18

Somatosensory-vestibular disconnect, such as seasickness

Question 19

When another car moving forward makes us think we’re moving, what type of sensory disconnect is this?

Answer 19

Visual-vestibular

Question 20

Which part of the brain “supervises” the somatosensory, vestibular, and visual inputs?

Answer 20

The cerebellum (and it’s the second processor, after the first processors of the sensors, since responses usually have to be within milliseconds)