Balance Impairments Flashcards
Fall
-unexpected event where person loses balance to a degree where pt lands on a lower surface
Postural Control
- ability to mntn body in equilibrium, statically and dynamically
- control of COM w/ respect of BOS
Maintenance of Balance affected by:
- body alignment/posture/position
- muscle tone
- postural tone
Anticipatory Control
- prep/proactive adjustments
- counteract disturbance of COM due to self initiated extremity movement
Reactive Control
-strategy or movement pattern to respond to an unexpected perturbation (movement or sensory)
Maintaining Balance Strategies
- Motor (hip, ankle, step)
- Sensory (vision, somatosensation, vestibular)
- Higher level processing (cognitive functioning): allows us to adapt
Ant/Post Balance Strategies
- distal to proximal muscles
- Ankle: small perturbations, quick
- Hip: large perturb, small surface
- Stepping: above strategies fail
Med/Lat balance Strategies
- hip response
- cross-over response
- lateral step response
Sensory Strategies
- visual system
- somatosensory system
- vestibular system
Visual System in Balance
- position of head
- reference to verticality
Somatosensory System in Balance
- position andm ostion of body w/ reference to supporting surface
- main input used by adults
Vestibular System in Balance
-position and movement of head with respect to gravity and inertia
Sensory Strategies in Quiet Stance
- all three sensory systems
- somatosens from all body parts
- increased sway with eyes closed
Sensory Strategies in Perturbed Stance
- somatosens input larger role compared to visual/vestibular
- vestib more active if support surface moves vertically or eyes are closed
Quickest system in balance
- Somatosensory system
- Faster than vision
Cognition & Postural Control
- Attention: requirements depend on task, age, balance capabilities
- may have increased/decreased sway in dual tasking
In pts with neurological problems, most falls occur
In the home
In pts with neurological problems, majority of falls due to:
tripping
Neural Contributions to Postural Control
- Spinal preparation
- Brainstem
- Basal Ganglia/Cerebellum
- Cortex
Medical Causes of Falls
- stroke, PD, dementia
- MSK: OA, Weakness
- Cardiovascular: syncope, impaired BP regs
- Medications
Neuro-Related Motor Abnormalities
- sequencing problems
- impaired adaptation
- impaired timing
- impaired scaling
Sequencing Problems
- prox to distal: Stroke
- co-contractions: PD
Impaired Adaptation
- synergistic movement
- due to cognitive impairment
- inability use right strategy, with the right Mm, with correct force at right time
Ex. PD
Impaired Timing
-delayed recruitment
Ex. Stroke, PD
Impaired Scaling
- hypermetria
- hypometria
Ex. cerebellar lesions
Neuro-Related Sensory Abnormalities
- impact of loss of one or multiple senses
- misinterpretation of stability limits
- inflexible weighting
Inflexible Weighting
- inability to switch from using vestibular, vision or somatosensory to another system when required
- leads to: visual dependency, surface dependency or sensory selection problems
highest population of fallers
-PD
