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KIN 225 > Neural control > Flashcards

Neural control Flashcards

1
Q

major components of Neural system
central nervous system (CNS)

A

brain (integrative control centres) and spinal cord
-cerebellum is the motor control centre

analyze and organize information
motor system planning and commands

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2
Q

major components of Neural system
peripheral nervous system (PNS)

A

outputs CNS commands and sends sensory information to CNS
primarily motto movements (movement and motor control)

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3
Q

afferent neurons

A

-relay sensory information from peripheral to the CNS (brain) along posterior column

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4
Q

efferent neurons

A

-relay information from the CNS (brain) to the peripheral or away from the brain along the pyramidal tract
-somatic nerves
-autonomic nerves

20:1 ratio afferent to efferent nerves

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5
Q

efferent neurons
two types
somatic neurons

A

motor neurons
-make up somatic nervous system
-innervate skeletal muscle

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6
Q

efferent neurons
two types
autonomic neurons

A

visceral or involuntary neurons
-make up autonomic nervous system
-activate smooth muscle, cardiac muscle, sweat and salivary glands, and some endocrine glands
sympathetic (fight or flight) and parasympathetic

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7
Q

which brain region is associated with processing of sensory signals?

A

parietal lobe

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8
Q

which part of the brain is primary motor cortex

A

pre-central gyrus

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9
Q

which part of the brain connects each hemisphere via commissural fibres ?

A

corpus callosum

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10
Q

which part of the brain is known as the motor control centre?

A

cerebellum

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11
Q

the ____ roots of the spinal cord contain _______ neurons, and relay information back to the CNS

A

dorsal
afferent

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12
Q

control of movement: voluntary

A

-require integration at the cerebral cortex
-learned movements may become “reflexive” (for example walking)
-muscle memory
ex. throwing a javelin

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13
Q

control of movement: reflexive

A

-sensor input (vision, vestibular, muscle)
-can be modulated by higher brain centres
-involved in posture
ex. regaining your balance after tripping

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14
Q

control of movement: rhythmic movements

A

-voluntary and reflexive
-initiated by cerebral cortex
-can be sustained without input from the brain
ex. running

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15
Q

previous research for paralysis

A

-focused on stem research to repair damage in individuals with spinal cord damage

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16
Q

new research on paralysis

A

-we know voluntary and rhythmic movements such as walking can actually become reflexive (not requiring input from the brain)

-if stimulus is provided below the level of the injury we may be able to obtain a state of walking

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17
Q

central pattern generator (CPG)

A

the CPG is a neural network in the lower part of the spinal cord that is thought to control locomotion

it does not require input from higher brain centres or reflexes , but the CPG output can be modified by input from the brain or reflexes

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18
Q

reflex arc (order)

A

-basic mechanism to process “autonomic muscle action-involuntary
-peripheral stimulus causes afferent neuron impulses to enter spinal cord
-transmit sensory input from peripheral receptors
-afferent neurons interconnect (synapse) with interneurons in the spinal cord to relay info to CNS
-Efferent signals return via anterior motor neuron to the muscles
-muscle responses

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19
Q

the central pattern generator can control walking without input form the brain or reflexes…

A

however the activity of the central pattern generator can be modified by input from senses, reflexes and the brain

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20
Q

touching a hot iron
reflex

A

pain receptors in the fingers transmit sensory info to spinal cord (via afferent neurons)

Efferent neurons activate the appropriate muscular response reflex action and muscular response occurs can reach the brain and tell the body to feel pain

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21
Q

motor unit represents an

A

alpha-motor neuron and the fibers it innervates

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22
Q

motor neurons pool represents a

A

Collection of alpha-motor neurons that innervate one muscle

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23
Q

nerve supply to muscle

A

single nerve or motor neuron supplies multiple individual muscle fibres (each muscles function)

-the number of muscle fibers per motor neuron (motor unit size ) is related to a muscles function
-simple movements
-complex movements

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24
Q

small motor unit

A

-only have a few fibres/motor neuron (those involved in fine movements like finger actions, eye action)
-complex precise movement

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25
Q

large motor unit

A

-may have hundreds of muscle fibers/motor neuron (those involved in gross movements like walking)
-simple movement

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26
Q

all muscle fibers within a given motor unit are the same __________

A

Type (I, IIa,IIx)

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27
Q

if a motor unit is activated (by higher brain centres) __________ in that unit contract

A

all the muscle fibers

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28
Q

motor neurons may receive input from other neurons originating higher up in the ________

A

central nervous system (closer to the brain) or the brain itself (motor cortex)
they may also receive input form reflexes, originating in the limbs (periphery)

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29
Q

dendrites

A

recipes impulses and direct toward cell body

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30
Q

cell body

A

control center

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31
Q

axon

A

delivers impulse to body

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32
Q

Schwann cell

A

covers bare axon

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33
Q

myelin sheath

A

electrical insulator of the axon

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34
Q

neurilemma

A

membrane covering the myelin sheath

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35
Q

nodes of ranvier

A

permit depolarization of axon

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36
Q

action potential is ______ along the axon of the motor neuron

A

propagated

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37
Q

axon is covered by

A

myelin (lipid sheath)

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38
Q

at certain points along the axon, there is a space in the myelin _____________

A

nodes of ranvier

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39
Q

nodes of ranvier allow

A

reinforcement of the current strength, but the current flows slower in these sections
without myelin, current leaks out and the action potential becomes weaker

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40
Q

nerve fiber conduction speed ______ in direct proportion to fibers __________

A

increases
diameter. and myelin thickness

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41
Q

the more myelin or thicker the axon the faster the conduction velocity of the axon
____ motor neurons have thicker axons

A

fast

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42
Q

neuromuscular junction-NMJ (motor endplate)
interface/junction between the ______

A

end of a motor neuron and a muscle fiber
-transmits nerve impulses to imitate muscle action

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43
Q

anatomical features of NMJ

A

-presynaptic terminals
-synaptic cleft
-postsynaptic membrane

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44
Q

T/F
a motor neuron pool is 1 motor neuron and many muscle fibers

A

false

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45
Q

T/F
a motor unit innervates a variety of fiber types

A

false

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46
Q

T/F
small motor units are typically involved in complex movements

A

true

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47
Q

T/F
alpha motor neurons are afferent neurons

A

true

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48
Q

at rest inside the muscle fiber (cell)
sodium is ____ on the inside as compared to the cell (ie more Na+ ________)

A

low
outside

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49
Q

at rest inside the muscle fiber (cell)
potassium is _____ on inside compared to outside the cell (ie more K+________)

A

high
inside

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50
Q

at rest inside the muscle fiber (cell)
sodium and potassium controlled by

A

Membrane permeability (wether or not a stimulus changes this)

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51
Q
A
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52
Q

at rest inside the muscle fiber (cell)
although Na+ and K+ are both positively charged there are more Na+ ions outside compared to K+ ions inside
thus the fibre cell is

A

more negatively charged on the inside

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53
Q

resting membrane potential (RMP)

A

-70mV
-inside negative relative to outside the membrane

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54
Q

relative to the RMP (-70mV)
depolarization: membrane potential becomes more _______ (>-70mV, closer to 0 or above)

A

positive
need to increase positive charge inside

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55
Q

relative to the RMP (-70mV)
repolarization: membrane potential becomes more _______ (back towards _ ___)

A

negative
RMP

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56
Q

relative to the RMP (-70mV)
hyper-polarization: membrane potential becomes more_______ than resting membrane potential (________)

A

negative
less than -70mV

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57
Q

changes in membrane polarization are ____________

A

signals used to receive, transmit, and integrate info within or between cells

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58
Q

types of signals:
endpoint signal

A

Depolarization OR hyper-polarization of MP, but won’t cause AP

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59
Q

types of signals
action potential:

A

substantial depolarization of MP

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60
Q

voltage changes
changing from -70 to -50 is

A

depolarization

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61
Q

voltage changes
changing from -70 to -90 is

A

hyper-polarization

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62
Q

voltage changes
changing from -50 to -60

A

repolarization

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63
Q

end point potential vs. action potential

A

wether or not it is an endpoint potential or an action potential generated in a motor neuron (thus wether the muscle reacts) depends on the of sum excitatory and inhibitory post-synaptic potentials (EPSP or IPSP)

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64
Q

excitatory input

A

known as excitatory postsynaptic potential
EPSP

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65
Q

inhibitory

A

known as inhibitory postsynaptic potential
IPSP

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66
Q

EPSP

A

depolarization of postsynaptic membrane
- facilitates (may lead to) AP

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67
Q

IPSP

A

hyper-polarizations of post synaptic membrane
- inhibits AP (are endpoint potentials)
- hyper polarizations are EPPs

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68
Q

facilitation
threshold/ all or none
if EPSP reaches threshold for ______ then the action potential transmits to muscle fibre

A

excitation
-threshold: minimum change of 15-20mV in MP depolarization ie -70mV to -50mV

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69
Q

action potential can be generated by
temporal summation

A

one or few neutrons can delivers repetitive sub threshold stimulus over a short period of time

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70
Q

action potentials can be generated by
spatial summation

A

a bunch of excitatory post synaptic potentials can be delivered from different presynaptic terminals

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71
Q

what is resting membrane potential

A

-70mV
inside of cell membrane more negative as more Na+ outside than K+ inside

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72
Q

depolarization - influx or reflux of what

A

influx of sodium

73
Q

repolarization - influx or reflux of what

A

efflux of potassium

74
Q

hyper-polarization -influx or reflux of what

A

extra efflux of postman

75
Q

action potential

A

substantial depolarization (threshold level) that will result in muscle contraction

76
Q

end point potential

A

depolarization or hyper polarization that does not porduce AP in muscle

77
Q

inhibitory post synaptic potentials

A

cause hyper polarization; therefore will result in an EPP (no contraction)

78
Q

excitatory post synaptic potentials

A

cause depolarization; therefore will result in an EPP, or AP If at threshold

79
Q

an action potential is

A

a rapid alternation in membrane potential whereby the polarity across the membrane becomes reversed
MP depolarizes from -70mV to +40 mV

80
Q

the concentration of ___- and ____- on the inside and outside of the cell determine polarization of the MP

A

sodium
potassium

81
Q

initiating the AP

A

-impulse travels down axon terminal
-calcium channel open and calcium diffuses into axon
-causes fusion of “synaptic vesicles” containing acetylcholine (ACh) with muscle membrane, excites membrane changing its permeably
-channels open to allow sodium in and potassium out

82
Q

initial opening of sodium (and potassium channels) due to binding of _______- with muscle membrane

A

acetylcholine

83
Q

opening of adjacent channels on the muscle membrane due to spread of electrical charge ________

A

voltage gated

84
Q

in review: muscle fibre stimulation/excitation
1. Impulse (AP)- moves down axon of _______

A

motor neuron

85
Q

in review: muscle fibre stimulation/excitation
2) calcium channels open and calcium _______

A

moves into terminal

86
Q

in review: muscle fibre stimulation/excitation
3) ACh primes for ——

A

release

87
Q

in review: muscle fibre stimulation/excitation
4) ACh transverses the synapse and binds to _____ on postsynaptic terminal (muscle membrane)

A

ACH receptors

88
Q

in review: muscle fibre stimulation/excitation
5) changes permeability of membrane (_____________)

A

influx/efflux of Na+ and K+

89
Q

in review: muscle fibre stimulation/excitation
6) depolarization generates an ______, if at threshold an ________

A

EPP
AP

90
Q

in review: muscle fibre stimulation/excitation
7) AP depolarization wave spreads throughout the ______network into muscle fibre

A

T-tubule

91
Q

ending excitation:
action potential

A

prepares muscle fibre for contraction by travelling down T-tubule

92
Q

ending excitation:
ACh hydrolysis

A

-ACh is broken down by cholinesterase to depolarize postsynaptic membrane
-axon resynthesizes acetic acid to form ACh so that the enter process is ready to go again

93
Q

complete muscle contraction
motor cortex

A

area in the brain where contraction originates

94
Q

complete muscle contraction
motor neuron

A

innervates muscle fibers (“motor unit”)

95
Q

complete muscle contraction
axons

A

branches of motor neuron; innervates muscle fibers

96
Q

complete muscle contraction
Acetyl choline

A

released from axon terminal

97
Q

complete muscle contraction
potassium and sodium

A

leaves
sodium enters muscle fiber

98
Q

complete muscle contraction
action potential travels down

A

transverse tubules

99
Q

complete muscle contraction
sarcoplasmic reticulum

A

releases calcium

100
Q

complete muscle contraction
calcium binds to ________’ troponin lifts ________

A

troponin
tropomyosin

101
Q

complete muscle contraction

_______ and ________ bind

A

actin and myosin

102
Q

motor unit functional characteristics classified by

A

twitch characteristics
tension characteristics
fatiguability

103
Q

twitch characteristics
3 general patterns
Type IIx

A

fast twitch, high force, fast fatigue

104
Q

twitch characteristics
3 general patterns
Type IIa

A

fast twitch, moderate force, fatigue resistance

105
Q

twitch characteristics
3 general patterns
Type IIa

A

slow twitch, low tension, fatigue resistant

106
Q

SAG (titanic depression)

A

phenomenon where under repetitive stimulus a motor unit first increases int tension, but then decreases or sags in response to the same titanic stimulus

107
Q

slow twitch

A

-slow contraction time
-slow relaxation time
- lower force output
-resitant to fatigue

108
Q

fast twitch a

A

-intermediate contraction time
-intermediate relaxation time
- moderate force output
-moderately resistant to fatigue

109
Q

-fats contraction
-fast relaxation time
- high force output
-fatiguable

A

=fast twitch x

110
Q

gradation of force/force of contraction
influenced by:
number of motor units recruited

A

recruitment of more motor units increases force

111
Q

gradation of force/force of contraction
influenced by:
discharge frequency

A

-increasing the rate (frequency) at which individual motor units

112
Q

gradation of force/force of contraction
influenced by:
neuromuscular fatigue decrease

A

-CNS/PNS
-neuromuscular junction
-muscle fiber

113
Q

Recruitment of fibres
recruitment order

A

Henneman’s size principle (small to large)
-ST to FT
- low to high activation

114
Q

Type II fibres are innervated by larger neurons and take to recruit (_______) than their slow fibre (________) counterparts thus, _________ are typically recruited first

A

high threshold
small, low threshold
ST fibers

115
Q

asynchronous and synchronous motor unit firing
skill vs. unskilled

A

-differences in degree of synchronic movement patterning

weightlifter vs. endurance runner

116
Q

estimating motor unit activation

A

electromyography (EMG) measure electrical signals created by muscle
-surface electrodes
-needle electrodes
HD EMG electrode arrays

117
Q

what is the importance of using EMG

A

-allows you to asses which muscles are activated during specific exercises
-allows you to asses the amount muscle are activated
-allows you to asses which muscles are under strain during work situations (important for injury prevention)

118
Q

EMG terms
raw EMG

A

the actual electrical signal

119
Q

EMG terms
rectified EMG

A

“negative” flipped to the “positive”

120
Q

EMG terms
integrated EMG

A

area under the rectified EMG

121
Q

Mean absolute value (MAP)

A

used to determine the amplitude of the signal

122
Q

Median frequency -MDF

A

used to determine the frequency firing
-when frequency of EMG is measured the median frequency is often used instead of the mean frequency
-Median is the middle score in a group of scores. EMG can be quite variable and using the median instead of the mean corrects the extreme scores

123
Q

median frequency of EMG

A

although it is affected by use of different fibre types, it is not accurate enough to determine muscle fibre types
-it is often used to asses fatigue

124
Q

would you expect median frequency to be higher in slow twitch or fast twice muscles? or would there be no difference? why?

A

Fast twitch muscles should have a higher median frequency
FT fire faster, so the frequency content should be higher

125
Q

would you expect median frequency to increase, decrease or stay the same with repeated muscle contractions? why?

A

decrease
they are fatiguing and then stop firing (FT)

126
Q

what is the important of using EMG?

A

-allows you to assess which muscles are activated during specific exercises

-allows you to assess the amount muscles are activated

-allows you to assess which muscles are under strain during work situations(important for injury prevention)

127
Q

force summation:

Before a muscle relaxes from a contraction, if ______ is applied force increases to a higher level
-this is due to _______ from the sarcoplasmic reticulum
-this calcium will bind more troponin, lifting tropomyosin allowing more_________

A

another electrical stimulus

increased release of calcium

myosin-actin cross bridges

128
Q

is it easier to achieve force summation wit slow or fast twitch

A

slow twitch
les likely to fully relax before the next force
-Type I muscle does not have time to completely relax before another stimulus is applied

can still have summation in all fibres

129
Q

tetanus
force will summate up to a maximal with repetitive stimulation
this maximal level is reached once ________________

A

all the sites for calcium on troponin have been occupied

130
Q

definitions of fatigue

A

-any reduction in force producing capacity of the muscle
-a transient decrease in performance capacity of a muscle when they have been activated for a certain time
-failure to maintain the required or expected force leading to a reduced perforce of a given task

131
Q

fatigue resistance
four components impact voluntary muscle action:

A
  1. central nervous system
  2. peripheral nervous system
  3. neuromuscular junction
  4. muscle fiber
    fatigue occurs from disruption in the chain of events between cns and the muscle fibre
132
Q

central v.s peripheral fatigue

A

central fatigue: failure of the neural drive or the initiation of the AP in the CNS

peripheral fatigue: fatigue occurring in the muscle cell

133
Q

central fatigue

A

bigger factor in endurance exercise

motivational and psychological factors involved

hypoglycaemia impairs CNS function

134
Q

peripheral fatigue

A

may occur due to mechanisms in
sarcolemma:
conductance of AP

T-tubules:
conductance of AP

sarcoplasmic reticulum
-release of calcium

nutriton/ metabolsim

135
Q

kinaesthetic sense

A

is our body awareness

136
Q

vestibular

A

Where our body is in space
-integrates with the visual system to enhance a sense of equilibrium and balance

137
Q

proprioceptive

A

Where the body is relative to other parts of the body
-receptors in muscles, joints and tendons

138
Q

proprioceptors relay information about muscular dynamics and limb movement (_________________)

A

kinaesthetic awareness

139
Q

the proprioceptors: muscles joints and tendons

A

relay info about muscle dynamics and limb movement to conscious and subconscious areas within the CNS

140
Q

proprioceptors monitor movement and allow for modification

A
141
Q

specialized sensory receptors sensitive to stretch, tension and pressure

A

muscles spindles
golgi tendon organ

142
Q

muscle spindles

A

receptor ( intrafusal fibers) in the muscle that is aligned parallel to muscle fibre ( extrafusal fibers)
-detects stretch in the muscle (muscle fiber length and tension)
-responsive to rate and amount of stretch

143
Q

muscle spindle- stretch reflex

A

-MS repsonds to stretch, sends excitatory input to the motor neuron in the spinal cord
-initiate an equal or stronger action to reduce this stretch
- causes muscle contraction
-inhibitory input is sent to the opposite (antagonistic muscle typically counteracts movement)
Ex. Elbow flexor being stretched the spindle is activated, the elbow flexor gets activated. The extensor will be inhibited

144
Q

activation of the muscle spindles relays _______ impulses through to the SC

A

afferent

145
Q

SC sends ________ impulses to cause reflex activation of the motor neurons of the stretched muscle

A

efferent

146
Q

myotatic reflex, aka the stretch reflex

A

stimulus: quadricep stretch
reciprocal inhibition
reaction: contraction of the quadriceps (knee extension)

147
Q

polymeric exercise

A

stretch - shortening cycle
-muscle is stretched, then shortened
the concentric (shortening) contraction is enhanced by the previous stretch

148
Q

how could you use stretch reflex to enhance strength and power performances during the push-up exercise?

A

Making the exercise more explosive, pushing yourself off the ground

149
Q

true or false

A

dynamic stretching (heating up the muscle) training quick response

150
Q

Golgi tendon organ

A

-receptors found at the junction between tendons and muscle fibres
-lie parallel to muscle fibre
-detect difference in tension generated by active muscles

151
Q

Golgi tendon organs: detect difference in tension generated by active muscle
respond to tension (activated) generated by:

A
  • muscle contraction
  • passive stretch
152
Q

Golgi tendon organs
protect muscle from excessive

A

load

153
Q

golgi tendon organs
if activated, GT sends impulses to elicit ______ inhibition

A

reflex
-inhibits muscle contraction causing muscle relaxation (good for PNF stretching)
opposite muscle (antagonist) is excited

154
Q

proprioceptive neuro-muscular facilitation (PNF)

A

-a type of stretching where the Golgi tendon organ is first activated of the Golgi tendon organ
-this causes inhibition of muscle concentration (causes muscle to relax)
-increases ability to stretch

155
Q

muscle spindle vs. Golgi tendon

A

muscle spindle:
-activated by change in muscle length (stretch)
-causes agonist muscle contraction
inhibits agonist muscle

Golgi tendon:
-activated by tension in active muscle
-causes agonist muscle relaxation
-excites antagonist muscle

156
Q

neural adaptation

A

-at the beginning of a training program, strength increases without and increase in muscle mass

-increased excitability of motor neurons (easier to recruit)

-enhanced nerve conduction
-alterations in motor unit recruitment (increased motor unit firing and synchronization)

157
Q

bilateral deficit

A

the sum of unilateral strength is greater than bilateral strength
- sum of the strength of each individual limb is greater than the strength of both limbs put together

158
Q

bilateral deficit
disappears with _______
increases with _______

A

bilateral training
unilateral training

implications for sport specific training:
-If your sport requires more unilateral movement, train unilaterally or the opposite

159
Q

causes of the bilateral deficit

A

-sensory input from one limb causing inhibition on the motor neuron innervating muscle of the opposite limb
-possible inhibition of type II fibers/decreased recruitment
-interfercne between hemisphere (inhibition of one side of the motor cortex on the other) during bilateral contractions
-perceived exertion with bilateral effort
-biomechanical factors (stabilization)

160
Q

how can we non invasively measure activation of the brain in humans?

A

fMRI
EEG
Trans-cranial magnetic stimulation

161
Q

functional magnetic resonance imaging (fMRI)

A

detects changes in oxygenated hemoglobin
- indicates where there are increases or decreases in oxygen consumption in the brain

gives an indication of what areas of the brain are activated or de-activated

162
Q

exercises that involve movement at more than one joint (leg press, lat pulldown) seem to be affected more by the ________ than exercises involving a single joint
why?

A

bilateral deficit
There is a lot more stabilization of the body than a knee extension (single joint)

163
Q

a greater ______ was produced during leg exercise than hand grip exercise

A

bilateral deficit

164
Q

activation of trunk stabilizers is the ______ for unilateral and bilateral exercises

A

same

165
Q

with unilateral exercise all assistance from the stabilizers is directed to one limb, but with bilateral exercises, the assistance from the stabilizers has to be spread ___________

A

to two limbs

166
Q

handgrip exercise does not involve much recruitment of the stabilizers in the trunk the _________

A

bilateral effect is less evident

167
Q

cross-education

A

a neural phenomenon

def: a neuromuscular transfer effect from unilateral training to the untrained contralateral limb

def: the increase in strength of the untrained contralateral limb after unilateral training

caused by alters nervous system activation

strength gain 52% relative to trained limb

168
Q

cross-education
magnitude related to strength increase of trained muscle
-52% of the strength observed in the trained limb
_________ effects shown with more novel (unfamiliar) tasks

A

greater

169
Q

cross-education
candidate mechanisms

A

-higher order brain mechanisms
-changes brain activation on both sides have been shown
- ipsilateral brain activation during unilateral movements

170
Q

what is the influence of handedness or limb dominance?

experiment: 3 groups- one trained only their right arm, one trained only left arm and one did no training
(measured brain activity before and after strength training)

A

appears to have a stronger effect when dominant limb is trained and transferred to non-dominant limb

theory why:
the dominant limb/hemisphere is more proficient at learning and mastering a task leading to better quality adaptations

-the non dominant limb has a greater capacity to improve (ceiling effect)

171
Q

cross education
candidate mechanisms

A

changes in brain activation on both the trained and untrained side have been shown following unilateral strength training

172
Q

how could you apply cross-education in a particle manner
what settings
with whom?

A

Injury on one side of the body (orthopaedic injury, one limb immobilized, offside the effects by training other limb)
Stroke rehabilitation

173
Q

Brain activation in cross-education

after right handed training there was an increased activation during left hadn’t exercise
left temporal lobe
right sensorimotor

A

left temporal lobe- involved recital motion knowledge

right sensorimotor cortex- involved in motor learning

174
Q

role of ipsilateral activation

A

increased ipsilateral brain activation in motor areas as grip contraction intensity increased

175
Q

cross-education and immobilization
(cast)

A

healthy participants using wires cast
-immobilized for 3 weeks on non-dominant (left) arm
3 groups
cast - train
cast
control
measured strength and muscle size

176
Q

summary of cast study

A
  1. when the left arm is casted, training of the right arm prevents loss of strength and perhaps loos of muslce mass in the left arm
  2. training of the non-broken wrist prevents loss of strength in the broken wrist
177
Q

cross education summary

A
  • magnitude related to strength increased of trained muscle

-effects normal shown in 4-6 week strength training program

-hypertrophy of trained, but not untrained limb

-effect shown for homologous muscle groups (quads on both sides)

-greater effects when task are novel (unknown)

-greater effect when dominant limb is trained and transferred to non-dominant limb

-can offset the effects of disuse during unilateral immobilization

-emerging that it can be useful in stroke rehabilitation (strength training less-affected limb to improve the more-affected)

178
Q

bilateral deficit

A

sum of unilateral strengths greater than bilateral strength.

  • decreases with bilateral training , force obtained using both limbs improves
  • higher in activities that require grater levels of stabilization as same level of stabilization required for one or two limbs; however, unilateral at the advantage
179
Q

cross education (basic def)

A

limb is trained; however opposite (untrained) shows improvement

KIN 225 (10 decks)

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