Motor Control Final Exam with Correct
Answers
How do we modify COM? - correct answer-by lowering the body (torque)
What is postural control? - correct answer-- permanent re-establishment of balance
- COM within BOS
- increase PC w/ reduced distance b/w COM and ground
- stances influence
What strategies can we employ to offset perturbations (anxiety) to the system? - correct
answer-- use mental imagery by setting a routine
- have preparation and practice
What muscles are excited in the ankle and hip strategy? - correct answer-- Ankle
strategy: paraspinal, hamstrings, gastrocnemius
- Hip Strategy: abdominals, quadriceps
What is Reflexive theory? - correct answer-self input= motor output
What is Hierarchical theory? - correct answer-low areas of brain(reflexive)-> brain stem
(subconscious PC)-> high areas of brain (voluntary movement)
What is Motor Program theory? - correct answer-relative, adaptive, motor
programs/memory control actions with commonalities
What is Dynamical Systems theory? - correct answer-self organization of movement to
coordinate DOF w/ consideration of environment and body of the individual
How is feedback used during closed loop movement? - correct answer-feedback is
received intra-trial and it detects errors and update memory and perceptual trace to
continue and terminate movement not needed
How is feedback provided to an open loop system? - correct answer-it does not provide
feedback however the control center provides all the information for effectors to carry
out movement
What is feedforward? - correct answer-anticipatory use of sensory information to
prepare for movement
How does spinal reflexes work? - correct answer-- Stimulate AMN (agonist)
, - Inhibit AMN (antagonist) via reciprocal inhibition
( Extrafusal fibers and intrafusal fibers stretch are detected via alpha and gamma
coactivation)
Stretch Reflex: How does platform tilting/backward movement influence EMG? - correct
answer-- Backward movement of platform: EMG shows from trial 1-4, there is a reduced
amount of time muscle stretch reflex activates (stretch reflex increases)
- Tilting of platform: EMG shows stretch reflex decreases b/c it's not needed due to the
tilting of the platform
- Stretch reflex is adaptive when its needed and when its not needed
What is Hoffman Reflex (H-Reflex)? - correct answer-- electrically induced
monosynaptic reflex.
- stimulate IA sensory (afferent) fibers from muscle spindles which excites AMN and
promote muscle activation
- produces H-wave at low stimulus strength and increases as magnitude increases then
declines so at very high magnitude, only H-wave disappears (only M-wave present)
What is the Flexor Withdrawal reflex? - correct answer-- spinal reflex in which the limb is
quickly withdrawn from painful stimulus, usually by simultaneous contraction of all flexor
muscles in the limb
- activation of pain receptors is sent to the spinal cord via Group III afferents
What is Crossed-extension reflex? - correct answer-- contraction of extensor muscles in
limb opposite of the one that is withdrawn
- a branch of the Group III afferent from the flexion withdrawal reflex innervates an
excitatory interneuron that sends its axons across the midline into the contralateral
spinal cord. There, it excites the alpha motor neuron that innervate the extensor
muscles of the opposite body part
Bernstein's motor learning stages - correct answer-stage 1: freezing of the limbs
stage 2: releasing the limbs
stage 3: exploiting the environment
Gentile's 2 Stage Model of Learning - correct answer-Stage 1: getting the idea of the
movement (learner gains an understanding of the basic coordination pattern that must
be organized to accomplish the motor skill; learner distinguishes the regulatory or
relevant information to the motor skill and non regulatory conditions or non
relevant/distractions to the motor skill)
Stage 2: fixation and diversification (Fixation is closed skill and goal is consistency;
diversification is open sills and goal is adaptable to changing environment)
Answers
How do we modify COM? - correct answer-by lowering the body (torque)
What is postural control? - correct answer-- permanent re-establishment of balance
- COM within BOS
- increase PC w/ reduced distance b/w COM and ground
- stances influence
What strategies can we employ to offset perturbations (anxiety) to the system? - correct
answer-- use mental imagery by setting a routine
- have preparation and practice
What muscles are excited in the ankle and hip strategy? - correct answer-- Ankle
strategy: paraspinal, hamstrings, gastrocnemius
- Hip Strategy: abdominals, quadriceps
What is Reflexive theory? - correct answer-self input= motor output
What is Hierarchical theory? - correct answer-low areas of brain(reflexive)-> brain stem
(subconscious PC)-> high areas of brain (voluntary movement)
What is Motor Program theory? - correct answer-relative, adaptive, motor
programs/memory control actions with commonalities
What is Dynamical Systems theory? - correct answer-self organization of movement to
coordinate DOF w/ consideration of environment and body of the individual
How is feedback used during closed loop movement? - correct answer-feedback is
received intra-trial and it detects errors and update memory and perceptual trace to
continue and terminate movement not needed
How is feedback provided to an open loop system? - correct answer-it does not provide
feedback however the control center provides all the information for effectors to carry
out movement
What is feedforward? - correct answer-anticipatory use of sensory information to
prepare for movement
How does spinal reflexes work? - correct answer-- Stimulate AMN (agonist)
, - Inhibit AMN (antagonist) via reciprocal inhibition
( Extrafusal fibers and intrafusal fibers stretch are detected via alpha and gamma
coactivation)
Stretch Reflex: How does platform tilting/backward movement influence EMG? - correct
answer-- Backward movement of platform: EMG shows from trial 1-4, there is a reduced
amount of time muscle stretch reflex activates (stretch reflex increases)
- Tilting of platform: EMG shows stretch reflex decreases b/c it's not needed due to the
tilting of the platform
- Stretch reflex is adaptive when its needed and when its not needed
What is Hoffman Reflex (H-Reflex)? - correct answer-- electrically induced
monosynaptic reflex.
- stimulate IA sensory (afferent) fibers from muscle spindles which excites AMN and
promote muscle activation
- produces H-wave at low stimulus strength and increases as magnitude increases then
declines so at very high magnitude, only H-wave disappears (only M-wave present)
What is the Flexor Withdrawal reflex? - correct answer-- spinal reflex in which the limb is
quickly withdrawn from painful stimulus, usually by simultaneous contraction of all flexor
muscles in the limb
- activation of pain receptors is sent to the spinal cord via Group III afferents
What is Crossed-extension reflex? - correct answer-- contraction of extensor muscles in
limb opposite of the one that is withdrawn
- a branch of the Group III afferent from the flexion withdrawal reflex innervates an
excitatory interneuron that sends its axons across the midline into the contralateral
spinal cord. There, it excites the alpha motor neuron that innervate the extensor
muscles of the opposite body part
Bernstein's motor learning stages - correct answer-stage 1: freezing of the limbs
stage 2: releasing the limbs
stage 3: exploiting the environment
Gentile's 2 Stage Model of Learning - correct answer-Stage 1: getting the idea of the
movement (learner gains an understanding of the basic coordination pattern that must
be organized to accomplish the motor skill; learner distinguishes the regulatory or
relevant information to the motor skill and non regulatory conditions or non
relevant/distractions to the motor skill)
Stage 2: fixation and diversification (Fixation is closed skill and goal is consistency;
diversification is open sills and goal is adaptable to changing environment)
