Chapter 7: Postural Control

Question 1

def - movement of the COM outside of the BOS

Answer 1

research definition of a fall

Question 2

def - an event that results in a person coming to rest inadvertently on the ground

Answer 2

clinical definition of a fall

Question 3

def - controlling the body’s position in space for the dual purposes of stability and orientation

Answer 3

postural control

Question 4

def - often used to describe both biomechanical alignment of the body and the orientation of the body to the environment

Answer 4

posture

Question 5

what orientation do we use for most postural tasks?

Answer 5

vertical orientation

Question 6

what sensory references do we use to establish a vertical orientation?

Answer 6

vestibular, somatosensory and visual systems

Question 7

def - modifying sensory and motor systems in response to changing task and environmental demands

Answer 7

adaptive orientation

Question 8

def - pretune sensory and motor systems for postural demands based on previous experience and learning

Answer 8

anticipatory aspects

Question 9

def - the ability to maintain an appropriate relationship between the body segments, and between the body and the environment for a task

Answer 9

postural orientation

Question 10

def - the ability to control the COM in relationship to the BOS

Answer 10

postural stability / balance

Question 11

def - a point that is at the center of the total body mass

Answer 11

center of mass

Question 12

def - vertical projection of the COM

Answer 12

center of gravity

Question 13

def - the area of the body that is in contact with the support surface

Answer 13

base of support

Question 14

____ and ____ can be used interchangeably

Answer 14

COM and COG

Question 15

def - center of the distribution of the total force applied to the supporting surface

Answer 15

center of pressure

Question 16

the ____ moves continuously around the COM to keep the COM within the support base

Answer 16

COP

Question 17

def - the scalar distance between the COP and the COM at any given point in time

Answer 17

stability

Question 18

def - the boundaries within which the body can maintain stability without changing the BOS

Answer 18

stability limits

Question 19

what are the components of motor control in quiet stance?

Answer 19

body alignments
muscle tone
postural tone

Question 20

plumb line (postural alignment)

Answer 20

mastoid process
just in front of the shoulder joints
the hip joints (or just behind)
just in front of the center of the knee joints
just in front of the ankle joints

Question 21

def - activation of antigravity muscles during quiet stance

Answer 21

postural tone

Question 22

def - the force with which a muscle resists being lengthened, that is, its stiffness

Answer 22

muscle tone

Question 23

components of the movement strategies during perturbed stance

Answer 23

body sway, feedback control, feedforward control (anticipatory), AP stability, ML stability, multidirectional stability

Question 24

what does the cerebellum do during postural control?

Answer 24

control of adaptation - ability to modify postural muscle amplitude in response to changing tasks and environmental conditions

Question 25

what does the basal ganglia do during postural control?

Answer 25

control of postural set - ability to quickly change muscle patterns in response to changing tasks and environmental conditions

Question 26

visual inputs

Answer 26

relationship of our body to objects in the environment

Question 27

somatosensory inputs

Answer 27

surface of support - position and movement about the body with reference to the BOS

Question 28

vestibular inputs

Answer 28

gravity - position and movement of the head with respect to gravity and inertial forces

Question 29

asking patients to move (lighter/heavier) objects at (slower/faster) speeds increases the likelihood that anticipatory postural adjustments will accompany movements

Answer 29

heavier and faster