Exam 2: stuff

Question 1

What requires more postural stability; sitting slouched with a post tilt or upright with an ant tilt?

Answer 1

anterior tilt.

• inc stability = dec mobility.

Question 2

2 tasks/parts/things of postural control?

Answer 2

Stability and Orientation

Question 3

Stability definition

Answer 3

• control of COM over BOS

Question 4

Orientation dfinition

Answer 4

• Relationship btwn body segments and environment

Question 5

Postural orientation stuff

Answer 5

• biomechanical alignment

- orientation of body and segements and the environment for the task

Question 6

Stability limits (LOS) definition

Answer 6

Boundaries of space in which body can maintain control without changing BOS

Question 7

Postural sway. cone of stability in Anterior, posterior, and lateral directions

Answer 7

• anterior = 15-20 degrees
• posterior = 3-5 degrees
• lateral = 5-8 degrees

Question 8

What effects one’s LOS?

Answer 8

• BOS
• velocity of COM
• task: actual and perceptual limits
• environment

Question 9

Postural control an impairment or funct. lim?

Answer 9

multisystem impairment??

Question 10

What is muscle synergies?

Answer 10

• coupling of groups of mm that are synchronized to act as a unit.

Question 11

Ankle strategy.

Answer 11

• small perturbation.
• move ant = activates gastroc, hammy, paraspinal
• move post = activates tib ant, quads, abs.

-distal to prox activation

Question 12

Hip strategy.

Answer 12

• large or fast perturbations
• narrow or compliant surfaces
• head and hips travel in opposite directions
• moving backward = will activate abs, quads
• moving forward = activates paraspinals and hammy

Question 13

Which has a more narrow limit of stability? hip or ankle?

Answer 13

Hip. COM does not move much.

Question 14

What is responsible for medial lateral stability?

Answer 14

Hips do most of movement.
-abductors and adductors

-Prox to distal. (hip muscles fire before ankle mm)

Question 15

What is required for multi-directional stability?

Answer 15

• combination of synergies. Practice difference patterns with patient (ankle, hip, stepping.)

Question 16

What are the 2 feed forward thing?

Answer 16

• postural prep

- postural accompaniments

Question 17

What is the feedback thing?

Answer 17

• postural feedback.

- i.e., after perturbations

Question 18

What are the 3 sensory strategies?

Answer 18

• vision, somatosensory, vestibular

Question 19

Anticipatory postural control

Answer 19

• postural adjustments are mvmts or muscle activation that occurs before voluntary movement to minimize potential disturbances in the body/limb etc.

*** lifting book example. Doing it yourself = anticipatory control.

Question 20

What role does vision have on anticipatory control?

Answer 20

• decreases latency period.

Question 21

Primary aging theory

Answer 21

• genetically determined.

- pessimistic view

Question 22

Secondary aging theory

Answer 22

• aging due to external insults

- optimistic view

Question 23

Factors for fall risk

Answer 23

• multiple contributing factors
• psychosocial
• environmental
• physiological

Question 24

Aging and influence on muscle

Answer 24

• sarcopenia, atrophy, dec type II fibers (lost at faster rate), dec motor units

Question 25

other changes with aging

Answer 25

- inc sway - change motor strategies - coactivation, timing, prox first then distal activation

Question 26

influence of aging on receptor concentration, afferent nerve fibers, internodal length, vibration threshold in big toe

Answer 26

decreases all. - vibration threshold increases in big toe. = 30% loss of peripheral receptors

Question 27

What is the absolute reference for balance system

Answer 27

- vestibular system | - 40% dec in vestibular hair and nerve cells by age 70

Question 28

aging does what to movement and reaction times

Answer 28

- increases both (makes slower)

Question 29

What 3 areas in brain atrophy

Answer 29

- prefrontal areas - temporal lobes - hippocampus ** also see dec in NT

Question 30

signal to noise ratio

Answer 30

- decreases with age Noise = background neuronal activity (HR,RR ect.)

Question 31

What is a fall?

Answer 31

unplanned descent to the floor

Question 32

how many people over 65 fall each year?

Answer 32

>1/3

Question 33

Adults in institutions fall more or less

Answer 33

fall more

Question 34

>50% falls happen at home. where most? and most injury falls where?

Answer 34

- most in bedroom | - most injuries = bathroom

Question 35

Do falls follow seasonal pattern?

Answer 35

- no. climate pattern.

Question 36

Single intervention that lowered risk of falling 12-20% =

Answer 36

exercise

Question 37

Sequencing problems

Answer 37

- coactivation | - lack or reverse of distal-to-prox activation

Question 38

Timely activation problems

Answer 38

- delayed onset latencies

Question 39

Adaptability problems to changing environment

Answer 39

- cant adapt | - scaling of forces ( too much or too little)

Question 40

Consequences of abnormal sequencing

Answer 40

- dec torque produced - large lateral shifts of COM due to imbalances - excessive movements of hip and knee when should be doing ankle

Question 41

What effect does AFO have on using ankle strategies?

Answer 41

- dec use of ankle strategy.

Question 42

2 parts of brain for "central set" stuff

Answer 42

- Basal ganglia and supplementary motor cortex

Question 43

What is a hypermetric response?

Answer 43

producing too much torque.

Question 44

2 key sensory input on postural control

Answer 44

- availability of senses to detect the position of the body in space - availability of accurate orientation and cues from environment

Question 45

What is a sensory selection problem?

Answer 45

when one or more orientation cues inaccurately report the body's position in space.