MOD 8: postural control

Question 1

What is the dynamic process of maintaining the body’s position in equilibrium called?

Answer 1

Balance (or postural stability)

It involves maintaining the center of mass over the base of support.

Question 2

Define center of mass.

Answer 2

The point that represents the center of total body mass

It is determined as a weighted average of the centers of mass of all body segments.

Question 3

What is the base of support?

Answer 3

The contact area between the body and the support surface

A wider base of support generally increases stability.

Question 4

Where does the center of gravity lie in anatomical position?

Answer 4

Slightly anterior to S2

This helps explain changes in postural torque.

Question 5

What is momentum?

Answer 5

The product of mass and velocity

It relates to both linear and angular motion.

Question 6

What are the limits of stability?

Answer 6

The sway boundaries for maintaining equilibrium

It refers to how far a person can move their center of mass without changing the base of support.

Question 7

What does efficient alignment do?

Answer 7

Decreases corrective effort needed to keep the center of mass over the base of support

Ideal alignment helps analyze posture and deviations.

Question 8

What systems influence normal balance?

Answer 8

• Nervous system
• Musculoskeletal system
• Environment

These systems work together to maintain postural control.

Question 9

What does the visual system provide?

Answer 9

Spatial orientation and anticipatory information about the environment

It is crucial for balance assessment.

Question 10

What is static balance?

Answer 10

Maintaining the center of mass within a fixed base of support while not moving

An example is quiet standing.

Question 11

What is dynamic balance?

Answer 11

Stabilizing the body when the support surface is moving or when the body is moving over a stable surface

Examples include walking or reaching.

Question 12

What is anticipatory balance?

Answer 12

Shifting the center of mass in preparation for a voluntary movement

An example is reaching for an object.

Question 13

What is reactive postural control?

Answer 13

Used to recover from unexpected perturbations

Examples include being bumped or slipping.

Question 14

What are the two types of control mechanisms in balance?

Answer 14

• Feed-forward (open loop)
• Feedback (closed loop)

They are used for different types of movements.

Question 15

What is the ankle strategy used for?

Answer 15

Small, slow perturbations on a firm surface with a wide base of support

It is a characteristic strategy for maintaining balance.

Question 16

What can impair sensory input for balance?

Answer 16

• Injury
• Pain
• Disease

These can alter proprioceptive, visual, vestibular, or somatosensory information.

Question 17

What is a common vestibular disorder?

Answer 17

Vestibular neuritis

It can cause dizziness and instability.

Question 18

What happens at the sensory motor integration level?

Answer 18

The brain’s ability to integrate and reweight sensory inputs may be impaired

This can lead to over-reliance on one sense.

Question 19

What are common musculoskeletal limitations that affect balance?

Answer 19

• Strength deficits
• Limited range of motion
• Joint stiffness

These can restrict postural strategies.

Question 20

What increases the risk of falls in older adults?

Answer 20

• Age-related sensory decline
• Slower motor responses
• Comorbidities

These factors interact to increase fall risk.

Question 21

What should be reviewed after any fall?

Answer 21

Medications

Adjustments may be needed to reduce fall risk.

Question 22

What are the three subsystems of balance?

Answer 22

• Sensory input
• Sensory motor integration
• Motor output

These subsystems work together to maintain postural control.