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
When does the body use the ankle strategy?
- responses to minor balance displacements
- designed to replace COM over BOS
- If COM offeset backwards anterior tibialis fires, if offset forward, gastroc/soleus fires. will move proximal to quads or hamstrings.
When does the body use hip strategy?
- response to rapid and/or large balance offsets.
- Also designed to replace COM over BOS
When does the body use stepping strategy?
for displacements beyond limits of stability. Designed to move BOS under COM. Can be any direction.
What are the stages of motor learning/stages of motor control?
- mobility- achieve position
- Stability- hold position against gravity, static postural control
- Controlled mobility- hold position during weight shifts, dynamic postural control
- Skill- motor control; coordinated movement characterized by precise timing and direction
How can balance be impaired?
- sensory input impairments
- decreased proprioception
- visual deficits in acuity or contrast
- vestibular loss - Sensorimotor Integration Impairments
- damage to basal ganglia, cerebellum or supplementary motor area impair processing - Motor Output impairments
- changes in musculoskeletal system: loss of ROM, strength, etc
How does aging affect balance?
- decrease strength
- slower response time
- decrease vision
- possible medications
- decreased ROM
- decreased activity tolerance
- comorbidities
- don’t stereotype: older people can have better balance than younger people
What are different modes to improve on balance?
- even/stable surfaces (easiest)
- Uneven/unstable surfaces
- surfaces tat decrease BOS
- pool
- balance master or other sophisticated devices
What are different posture/positions that can progress balance?
- supine/prone
- four point
- tall kneeling
- half kneeling
- modified plantigrade
- standing
- various positions of limbs in relation to body
What are different movements to improve balance?
- Static: still, no movement, isometric contractions
- Dynamic: balance
- Movement of body/limbs while maintaining balance
- Movement within and outside limits of stability, ie reaching
What are the dosage parameters for balance?
- environment
- sequence
- frequency, intensity, and duration
What should the environment be for balance training?
- Dependent on pt’s situation: frail elderly vs athlete
2. safety is the key factor
What should the sequence be for balance training?
- work from simple to complex
2. work from static to dynamic
What should the frequency, intensity, and duration be for balance training?
- increased frequency increases likelihood of progress/change
- Intensity generally not prescribed because no external resistance or load is applied (mostly IP/skilled, may add resistance in an OP setting)
- Duration determined by fatigue
What are the precautions for balance training?
- Patient’s safety!!!!
What are the contraindications for balance training?
- Patient’s who are inherently unsafe in balance-challenged positions (ie cognitive impairments limiting understanding purpose, mechanics, instructions of the activity)
