Postural Control

Question 1

Postural Control

Answer 1

controlling body’s position in space for stability and orientation

Question 2

Postural Stability

Answer 2

controlling CM in relationship to BOS

Question 3

Postural Orientation

Answer 3

maintaining appropriate relationship between segments and between body and environment for a task

Question 4

T or F : Postural stability and orientation are critical for independence in functional tasks

Answer 4

True!

Question 5

T or F : Stability and orientation requirements vary with task and environment

Answer 5

True!

Question 6

Musculoskeletal Individual Systems for Postural Control

Answer 6

Joint ROM
Spinal Flexibility
Muscle Properties
Biomechanical relationships among linked segments & movement strategies

Question 7

Neural Individual Systems for Postural Control

Answer 7

Motor Synergies
Sensory (Vision, vestibular, somatosensory(
Cognitive

Question 8

Task Requirements for Balance in Postural Control

Answer 8

Steady-State Balance
Proactive/Anticipatory Balance
Reactive Balance

Question 9

Steady State Balance

Answer 9

control CM relative to BOS in predictable, non-changing conditions

ex: standing still, sitting, constant velocity walking

Question 10

Proactive/Anticipatory Balance

Answer 10

activate muscles for balance control in advance of potentially destabilizing voluntary movements

ex: lifting heavy object, stepping onto curb

Question 11

Reactive Balance

Answer 11

recover stable position after unexpected perturbation

ex: tripping or getting bumped into in a crowd

Question 12

T or F : Proactive balance control relies on feedforward / open loop mechanisms

Answer 12

True! Anticipatory postural adjustments are made in advance of a voluntary movement that is potentially destabilizing

Question 13

T or F : Reactive Balance relies on feedback / closed loop mechanisms

Answer 13

True! Corrective postural control strategies occur in response to detected sensory errors after external perturbation

Question 14

Environmental Constraints of Postural Control

Answer 14

Support Surfaces
Sensory Context
Cognitive Load

Question 15

Inverted Pendulum Model of Postural Control

Answer 15

Humans maintain standing balance by maintaining active control of position of their CM relative to fulcrum formed by their feet

For small perturbation, the ankles exert a torque that counteracts gravity and prevents from falling over

Question 16

T or F : The Inverted Pendulum Model suggests that as level of perturbance increases, the following strategies are used in this order: ankle, stepping, hip

Answer 16

False! As perturbance increases, the strategy order is Ankle, Hip, Stepping

Question 17

Ankle Strategy

Answer 17

small perturbations

Forward Sway: posterior mm. active in caudal to rostral
Backward Sway: anterior mm. active in caudal to rostral

Ankle & Trunk IN PHASE for both

Question 18

Hip Strategy

Answer 18

larger perturbations

Forward Sway: anterior mm. active in rostral to caudal w/ ankle pf
Backward Sway: posterior mm. active in rostral to caudal w/ ankle df

Ankle & Trunk OUT OF PHASE in both

Question 19

Stepping Strategy

Answer 19

CM out of BOS, largest perturbance

change in support & need to realign BOS under changing CM

Question 20

Theories of Sensory Integration for Postural Control

Answer 20

Intermodal Theory
Sensory Weighting Hypothesis

Question 21

Intermodal Theory of Sensory Integration in Postural Control

Answer 21

ecological approach
Postural orientation emerges from sensory systems interacting in a Relationship of 3
the senses provide CNS w/ info for postural orientation

Question 22

Sensory Weighting Hypothesis of Sensory Integration in Postural Control

Answer 22

each sense provides unique contribution to postural control

the system can reweight sensory inputs to optimize stability in altered sensory environments

ability to reweight can be tested with CTSIB (Clinical Test of Sensory Integration on Balance)