Impairment: Balance Dysfunction Flashcards
Postural Control: Definition
Controlling the body’s position in space for the purpose of STABILITY and ORIENTATION
Postural Control: Types
- Reactive (compensatory)
- Proactive (anticipatory)
- Adaptive
- Tilting Reactions
Reactive (compensatory)
Reaction to external force
Proactive (anticipatory)
Responses that occur in anticipation (feedforward)
Adaptive
Appropriately modify via sensory and motor
Tilting Reactions
Reposition COM within BOS for changing surface
Postural Orientation (POSTURE) definition
Ability to maintain appropriate relationship between:
- Body segments
- Body and environment for a given task
Balance (Postural Stability) definition
- State of PHYSICAL EQUILIBRIUM involving stabilizing and destabilizing forces
- CONTROLLING COM OVER BOS
COM
- Located at approximately S2
COG
- Vertical Projection of the COM
BOS
Area that is in contact w/ support surface
Static POSTURE/BALANCE:
- COG falls within BOS
- maintains particular posture agains gravity
Postural Fixation Reactions
Stabilize the body against thrust force
Dynamic POSTURE/BALANCE
- COG falls outside BOS
- maintaining stability during movements of body and body segments
- changing surface (walking)
Functional Task Analysis (list)
- Mobility
- Stability
- Controlled Mobility
- Skill
Mobility
Ability to move from one position to another safely
Stability
- (static postural control)
- COM over BOS
Controlled Mobility
- (dynamic postural control)
- maintain postural stability while moving w/ COM over BOS
- WEIGHT SHIFTING
Skill
- Ability to consistently perform “coordinated movement” for purposes of INVESTIGATION/INTERACTION w/ environment
Line of Gravity (LOG): Definition
Ideal posture, where body segment axes should fall
LOG “ideal” position:
- slightly anterior to ankle and knee joints
- slightly posterior to hip joint
- thru midline of trunk
- anterior to shoulder
- thru external auditory meatus
Center of Pressure (COP)
- Both VERTICAL and HORIZONTAL shear forces
- within foot unilaterally
- between foot bilaterally - LOG and COP constantly change b/c postural sway
Center of Force (COF)
Only vertical forces
Postural Sway
- shifts from SIDE to SIDE and HEEL to TOE
- STEADINESS:
- holding given posture w/ least amount of movement
- increased sway = increased unsteadiness
Limits of Stability (LOS)
Maximum angle from vertical that can be tolerated w/o loss of balance
- static standing = 12 degrees of motion in sagittal plane - static standing = 16 degrees of motion in frontal plane
Sensory Processes for Balance Control
- Visual System
- Somatosensory Inputs
- Vestibular System
Visual System w/ Balance:
- Helps perceive movements via VISUAL PROPRIOCEPTION
- Exam:
- Focal Vision: central vision
- Ambient Vision: peripheral vision
CN Visual Deficits:
- CN II: depth perception, visual acuity
- CN III: lid droop, outward eye, dbl vision, decrease depth perception
- CN IV: head tilt, downward dbl vision, trouble w/ stairs (tripping)
- CN VI: inward eye posture, turns head towards affected eye
Somatosensory Inputs:
- Cutaneous and Pressure sensations
- Muscle and Joint Proprioceptors
Sensory Input: Examination
- Romberg Test: assesses DORSAL COLUMN (eyes open/closed)
- Sensory Testing:
Vestibular System:
- vestibulo-ocular reflex (VOR)
- vestibulospinal reflex (VSR) (“no” walking)
- labyrinthine righting reactions (LRR)
Vestibular System: Examination
- Ocular Fixation
- Smooth Pursuits
- Saccadic Eye Movements
- Convergence
- VOR
Vestibular System: Treatment
- Canalith Repositioning Treatment (CRT)
- rapid repositioning of head to move crystals (periph def) - Habituation Exercises
- repeated positioning of pt in positions to elicit symptoms - Gaze Stability Exercises
- Postural Stability
Motor Processes: Automatic Postural Synergies
- Ankle (Romberg)
- Hip
- Stepping (reaching/grasp) (nudge)
- Suspension (crouching down)
3 movement systems CNS uses to regain balance
- Stretch Reflex (ankle, hip, step strategies)
- Automatic Postural Reactions (righting/equilibrium)
- Voluntary Responses (cortical)
Static Tests:
- Single Limb Stance (SLS or OLST)
- Romberg Test
- Tandem Romberg Test
Dynamic Tests
- Functional Reach Test (FR)
- Multidirectional Reach Test
Berg Balance Scale (BBS)
- originally for stroke pts
- static and dynamic tests (14 functional tasks)
- 5-point ordinal scale ; 56 total points
- fall predictor
- 54 to 36, each 1 point = 7% increase fall risk
- <45 = high fall risk. <36=100% fall risk
Berg Balance Scale: functional tests (14)
1: sitting to stand in
2: standing unsupported
3: sitting unsupported feet on floor
4: standing to sitting
5: transfers
6: standing unsupported w/ EC
7: standing unsupported w/ feet together
8: reaching forward w/ outstretched arm
9: pick up object from floor
10: turning to look behind L and R shoulders
11: turn 360 degrees
12: alternating step stool touches
13: standing unsupported, one foot in front
14: standing on one leg
Fullerton Advanced Balance Scale (FAB)
- for higher functioning older adults who pass BBT
- 10 items, scored 0-40 (0-bad, 40-good)
BESTest
- tests multiple aspects of postural control
- 36 items in 6 groups:
Biomechanics constraints
Stability limits
Anticipatory transitions
Postural responses
Sensory orientation
Dynamic gait
