Balance Flashcards
What is the state of an object when the resultant load actions are zero?
Balance (equilibrium)
This is based on Newton’s First Law.
What is the Centre of Gravity (COG)?
The point about which the mass is evenly distributed
It is also referred to as the Centre of Mass.
What does Base of Support (BOS) refer to?
The area beneath an object or person that includes every point of contact with the supporting surface.
How is balance maintained?
By keeping COG within BOS
This may not necessarily be within the body.
What happens when COG moves forward of BOS?
It is a precursor event to walking.
List some factors affecting balance.
- Age
- Agility
- Anxiety
- Attention
- Body shape
- Brain (control centre)
- Breathing
- Confidence
- Fear
- Insight
- Level of Consciousness
- Motivation
- Musculoskeletal system
- Neuromuscular system
- Pain
- Proprioception
- Sensation
- Speech
- Vestibular system
- Vision
- Visual spatial perception
Define postural control.
An individual’s ability to achieve and maintain balance during a desired posture or activity.
What are the two main purposes of postural control?
- Stability
- Orientation
What is steady state balance?
Maintain stability in conditions.
What is proactive balance?
Ability to generate postural adjustments to maintain stability in advance of goal-directed movement.
Why is normal postural control important?
It is critical for the efficient and effective performance of all goal-directed activities.
What are the main components of sensory input in postural control?
- Visual
- Vestibular
- Somatosensory
What does the vestibular system detect?
Linear acceleration, gravity forces, and tilting motions.
What are the three main afferent sources of peripheral sensory input?
- Somatosensory system
- Vestibular system
- Visual system
Describe the vestibulo-ocular reflex (VOR).
Generates eye movements that enable clear vision while the head is moving.
What happens during a mild perturbation?
Ankle response engages calf muscles.
What is the effect of dual task conditions on postural stability?
The ability to maintain postural stability is reduced.
What are common adaptations for balance?
- Wide base
- Shuffling gait
- Favoring stronger side
- Use of aid
- Avoiding busy environments
What is benign paroxysmal positional vertigo (BPPV)?
Short episodes of intense dizziness when moving the head in certain directions.
What is the lifetime prevalence of BPPV?
2.4%
Based on von Brevern et al, 2007.
What is a common cause of BPPV?
- Idiopathic (50-70%)
- Head Injury (7-17%)
- SCI (14.5%)
- Vestibular Neuritis (15%)
How does Parkinson’s Disease (PD) affect balance?
PWPD fall 5x more than age-matched controls.
What is a symptom of Multiple Sclerosis (MS) related to balance?
Increased sway in quiet stance.
