Balance/Postural Control Flashcards
1
Q
Define postural control
A
- the act of maintaining, achieving, or restoring a state of balance on a support surface during any functional task that involves movement
2
Q
Stages of motor control
A
- movement
- stability
- controlled mobility
- skilled movement
3
Q
Where is the center of mass
A
- at 2nd sacral vertebra in anatomical standing
4
Q
Line of gravity through the body in standing
A
- anterior to ankle
- anterior to knee
- posterior to hips
- anterior to thoracic vertebrae
- anterior to shoulders
5
Q
Describe limits of stability/ cone of stability
A
- max distance one can lean/reach without changing base of support & without loss of balance
6
Q
Steady state balance
A
- quite sitting/standing
7
Q
Reactive balance
A
- balance reactions in response to brief perturbations/movement in COG
- mostly use feedback mechanisms in response to sensory inputs
- use some automated motor control strategies here
8
Q
Proactive balance
A
- postural adjustments in anticipation of voluntary movements that will move COG
- use feedforward mechanisms
9
Q
Postural alignment
A
- perfect alignment when line of gravity passes through structures as expected
- minimal muscle activity required
10
Q
Steadiness/postural sway
A
- ability to maintain COM/LOG at place with minimal movements
- can be measured by center of pressure movements on force plates
- normally exhibit small postural sway during standing
- sway envelope = path of excursion of the center of pressure during quite standing
11
Q
Fixed support strategies
A
- used to control center of mass over fixed base of support, center of mass remains within limits of stability
- ankle, hip, and suspension strategies
12
Q
Ankle strategy
A
- move COM of body as a block about ankle joints
- used when sways are small/slow
- muscles are activated distal to proximal
- during forward sway -> gastroc, hamstrings, & paraspinals
- during backward sway -> tib ant., quads, & abdominals
- used on firm support surface
13
Q
Hip strategy
A
- moves COM by flexing/extending/ABD/ADD hips
- used with larger/faster sway
- muscles activated proximal to distal
- forward sway -> abdominals & quads
- backward sway -> paraspinals & hamstrings
- used when support surface is small/narrow/compliant
14
Q
Suspension strategy
A
- moves COM down by flexing hips/knees & flexing trunk
- may progress to squating
15
Q
Change in support strategies
A
- used to control COM over moving base of support when COM moves out of loss of stability
- stepping & reaching/grasping strategies
16
Q
Stepping strategy
A
- brings COM back within loss of stability by taking a rapid step in the direction of the destabilizing force
- recruited in response to fast large perturbations when ankle/hip strategies are not adequate to recover postural control
- not a strategy of last resort it is recruited quickly ahead of ankle/hip strategies if CNS perceives a big perturbation
17
Q
Reaching/grasping strategy
A
- bring COM within loss of stability by extending base os support by reaching/grasping using UE
18
Q
What sensory systems are involved in balance
A
- visual
- somatosensory
- vestibular
19
Q
Visual system
A
- has roles in both feedforward and feedback balance mechanisms
- Feedforward: focal vision (central vision, to see obstacle ahead of you & react beforehand & needed for proactive/anticipatory postural control
- Feedback: ambient vision (focal & peripheral vision), to regain postural control after perturbations & needed for reactive postural control
20
Q
Somatosensory system
A
- information from touch receptors and proprioceptive sensations from muscles, tendons, and joints
- has roles in both feedforward and feedback mechanisms
- provide info about orientation & movement of body in relation to support surface
21
Q
Vestibular system
A
- provides CNS with info about position.movement of head with respect to gravity/inertial forces
- info about linear/angular acceleration
- functions to stabilize gaze during head movements, regulates tone in postural/antigravity muscles
22
Q
Sensory Organization Test (SOT) scoring
A
- 1 = minimal sway
- 2 = mild sway
- 3 = moderate sway
- 4 = loss of balance
23
Q
Modified Clinical Test for Sensory Integration of Balance (mCTSIB)
A
- performs standing on stable surface eyes open then closed
- performs standing on unstable surface eyes open then closed
- does not test/perform inaccurate visual input
24
Q
Balance tests for steady state balance
A
- single limb stance time (30s)
- Romberg test (feet together 30s)
- CTSIB/mCTSIB
25
Q
Balance tests for anticipatory balance
A
- functional reach test
- multi-directional reach test
- star excursion balance test/Y-balance test
26
Q
Balance tests for reactive balance
A
- retropulsive pull test (pull pt backwards)
- push and release test (0 = recovers with 1 step, 1 = 2-3 small steps, 2 = 4 or more steps, 3 = multiple steps & needs assistance to prevent fall, 4 = falls w/o attempting steps)
27
Q
Balance tests for sitting balance
A
- Static sitting balance: postural symmetry, pelvic tilt, base of support, biomechanical constraints, & sensory orientation
- Dynamic sitting balance: stability limits & verticality, anticipatory postural control, and reactive postural control
28
Q
Assessment of balance at impairment level
A
- Motor systems: ankle, hip, and step strategies
- Sensory systems: stable to unstable surface
- Cognitive systems: dual task testing
29
Q
Seated balance tests
A
- sitting balance assessment
- FIST (function in sitting test)
- SATCo
30
Q
Standing balance tests
A
- FRT/MDRT (functional reach test)
- Romberg/Sharpened Romberg (feet together/tandem)
- SLST (single limb stance time)
31
Q
Combined sitting & standing activities to assess balance
A
- TUG (time up & go; more than 13s is cut off for fall risk)
- 5TSTS (5x sit to stand)
- 30SCST (30s sit to stand)
- PASS (postural assessment seated/standing)
- BESTest (cut off for fall risk is <69%)/miniBESTtest (cut off <23/28)
- DGI (dynamic gait index)
- FGA (functional gait assessment)
32
Q
How do you improve balance
A
- appropriate intensity and volumes
- need to work at the levels where patients experience some loss of balance
33
Q
Interventions for static/steady state balance control
A
- having patient maintain progressively difficult static postures: sitting, quadruped, half kneeling, tall kneeling, standing, lunge, squat positions
34
Q
How to train reactive balance control
A
- requires external perturbations
35
Q
How to train anticipatory balance control
A
- requires change of posture during functional activities
- example: reach in all directions to touch or grasp objects, pick objects from floor, catch ball, tap balloon, or kick ball
36
Q
Combined reactive and anticipatory balance control activities
A
- seated reaching with perturbations
- gait with head turns and perturbations
- sit to stands with perturbations
