Stance and Posture

Question 1

what is posture?

Answer 1

alignment of body segments

Question 2

what tool is commonly used to assess posture?

Answer 2

a plum line

Question 3

what muscles support upright posture?

Answer 3

antigravity muscles

Question 4

what forces are required to maintain stance?

Answer 4

LOG and muscles

Question 5

t/f: the extensors have to work to keep up upright

Answer 5

true

Question 6

postural sway occurs mostly where?

Answer 6

at the ankle

Question 7

why does postural sway occur?

Answer 7

bc of things inside us moving constantly such as blood flow, digestion, and beating heart which affect the ability to stay still

Question 8

how much sagittal plane sway is there normally?

Answer 8

12 deg

Question 9

how much frontal plane sway is there normally?

Answer 9

16 deg

Question 10

what is the COM?

Answer 10

total body mass and the point where the body is in complete equilibrium

Question 11

where is the COM normally located?

Answer 11

anterior to S2

Question 12

what is the LOG?

Answer 12

vertical projection of the COM to the ground

Question 13

what is stance posture?

Answer 13

balance of forces in stance

Question 14

what force creates an external moment arm in stance posture?

Answer 14

gravity

Question 15

t/f: muscles have to contract against the pull of gravity to stay in stance posture

Answer 15

true

Question 16

where is the LOG at the knee?

Answer 16

anterior to the knee jt but posterior to the patella

Question 17

what muscles at the knee have to resist the pull of gravity?

Answer 17

posterior muscles and tissues

Question 18

where is the LOG at the ankle?

Answer 18

4-6 cm anterior to the ankle

Question 19

what muscle resists the pull of gravity at the ankle?

Answer 19

soleus

Question 20

where is the LOG at the hip?

Answer 20

posterior to the axis of the hip

Question 21

what is the normal ASIS-PSIS angle?

Answer 21

12 deg

Question 22

what is the normal angle of inclination at the sacrum?

Answer 22

30-40 deg inclination

Question 23

what forces are required for functional stance at the hip?

Answer 23

LOG posterior to the hip axis

slight illiacus activity to counteract gravity

Question 24

what forces are required for functional stance at the head and trunk?

Answer 24

LOG falls on concavity of spinal curves

thoracic erector spinae active to maintain posture

cervical extensors balance occiput on the atlas

Question 25

what is the ankle strategy?

Answer 25

control of psture initiated at the ankle the 1st place where resistance happens used for small perturbations

Question 26

what is the hip strategy?

Answer 26

the 2nd place where resistance happens used for larger perturbations

Question 27

when are the stepping or reaching strategies used?

Answer 27

perturbations so big that the hip strategy isn't enough to maintain balance large, rapid change in COM

Question 28

what is the BOS?

Answer 28

area of the body in contact w/support surface

Question 29

what is the COP?

Answer 29

distribution of total force on supporting surface

Question 30

balance is a combination of the interactions bw what 3 factors?

Answer 30

1) individual 2) environment 3) postural task

Question 31

what factors are a part of the individual?

Answer 31

muscular and neural systems postural control systems

Question 32

what makes up cognition?

Answer 32

attention, motivation, intent

Question 33

what are factors that make up the environment?

Answer 33

uneven surfaces, ice, moving/changing surfaces, dark/cloudy

Question 34

what is a steady state?

Answer 34

predictable and steady least challenging posture

Question 35

what is proactive state?

Answer 35

activating muscles b4 the action thinking about how much force you will need to use

Question 36

what is reactive state?

Answer 36

able to recover from an unexpected purturbance like tripping, getting pushed, etc.

Question 37

are proactive and reactive actions feedforward or feedback?

Answer 37

both

Question 38

what is feedback?

Answer 38

responses to things around you

Question 39

what is feedforward?

Answer 39

anticipation of what's going to happen

Question 40

what are adaptations?

Answer 40

refining and tuning response to task demands and environment

Question 41

how does postural control develop?

Answer 41

cephalocaudal progression (from head down) head support and vision-->sitting independently-->reaching b4 anticipatory control head support-->sitting-->reaching

Question 42

when does lifting the head occur?

Answer 42

1 month

Question 43

when does sitting w/support occur?

Answer 43

4-7 months

Question 44

when does sitting w/o support occur?

Answer 44

4-7 months

Question 45

when does creeping/crawling occur?

Answer 45

8-10 months

Question 46

what is creeping?

Answer 46

army crawl both arms moving together to crawl

Question 47

how is crawling different from creeping?

Answer 47

uses alternating arm instead of both arms at the same time

Question 48

when does the pull to stand occur?

Answer 48

9-10 months

Question 49

when does independent stance occur?

Answer 49

12-13 months

Question 50

when does walking occur?

Answer 50

14-18 months

Question 51

what tests can be used to evaluate development?

Answer 51

gross motor fxn measure (GMFM) Peabody developmental motor scale (very common) movement assessment of infants

Question 52

what changes in posture occur with aging?

Answer 52

decreased strength, power, activity level increased fear of falling (FOF) impacted by lifestyle and activity very variable