Balance Flashcards
Define balance.
the ability to maintain COG over BOS.
-requires the ability to maintain a position, stabilize during voluntary activities, and react to external perturbations.
Define coordination.
the ability to perform smooth accurate, and controlled motions
Define postural sway.
the normal continuous shifting of the body’s COG over its BOS
Define limits of stability.
The area of space in which a person can maintain balance without changing position.
What are the 3 sensory systems that contribute to maintain an upright posture?
- somatosensory system
- visual system
- vestibular system
What does the somatosensory system do?
- provides information about relative location of body parts
- proprioception- where you are in space
- Kinesthesia- how you are moving in space
- sensory receptors located in the soft tissue structures around the joint (muscle, capsule, ligaments, tendons)
it’s the musculoskeltal part.
What does the visual system do?
- provides information about head position relative to the environment
- orients the head to maintain level gaze (optical righting)
- provides information about movement of surrounding objects
What does the vestibular system do?
- provides information about orientation of the head in space and on acceleration.
- consists of the semicircular canal, utricle, and saccule, and otoliths (small inner ear bones)
What are the types of balance control?
- steady state
- proactive
- reactive
What is the steady state balance control?
maintenance of quiet sitting/standing balance or ongoing gait (on level, familiar surfaces)
-instability = inability to control COM relative to BOS
What is proactive balance control?
postural adjustments used in an anticipatory manner
-having all three systems of balance is key
What is reactive balance control?
the ability to recover from an unexpected perturbation
-cognitive ability is key
What are the factors that influence the selection of balance strategies?
- speed and intensity of displacing forces
- characteristics of the support surface
- Magnitude of the displacement of the COM
- Subject’s awareness of the disturbance
- Subject’s posture at the time of perturbation
- Subject’s prior experiences
What are the movement systems involved in regaining balance?
- reflexes
- stretch reflexes independent of a task - voluntary responses
- dependent on task but results in highly variable outcomes - Automatic postural reactions
- quick, relatively invariant movements; modifiable depending on the task
What are the automatic postural reactions?
- Ankle
- hip
- Stepping strategy