Flashcards in Lecture 23: Kinesthesia Deck (25)
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1
Kinesthesia is the awareness of :
the position of the body segments in space and in relation to each other
2
Kinesthesia allows us to :
perform movements without continuous visual control, to adjust patterns of control variables, and perform tasks requiring multi-limb coordination.
3
_______ are the source of kinesthetic information.
Proprioceptors
4
Problems with Kinesthesia: Under isometric conditions, an increase in the level of muscle activation leads to _____.
an increase in the activity of the gamma system and an increase in the firing level of muscle spindle sensory endings.
This may be interpreted by the central nervous system as a joint motion corresponding to an increase in muscle length.
5
Problems with Kinesthesia: Under non-isometric conditions, an increase in the level of muscle activation leads to _____
muscle shortening, accompanied by an increase in the activity of the gamma system.
As a result, one may see the same average level of firing of muscle spindle sensory endings at different joint positions.
6
Kinesthetic Perception Problems: Under isometric conditions, an increase in the level of muscle activation leads to _____.
an increase in the stiffness of muscle fibers.
This leads to a relative shortening of muscle fibers and a stretching of the tendon.
7
Kinesthetic Perception Problems: Joint torque is the sum of ____.
products of muscle forces and corresponding lever arms
8
Kinesthetic Perception Problems: Joint movement leads to a change in the lever arm. Therefore, joint torque is dependent on ____.
both muscle force and joint angle.
9
If a system within the human body looks imperfectly designed, we have probably ________.
overlooked or misinterpreted something.
10
Accurate kinesthetic perception is likely to emerge through participation of ______________.
signals from various sensors
11
Kinesthesia has more ______ than _____.
positive features than problems
12
_________ sense is still present with artificial joints.
Position
13
An efferent copy represents _____.
a copy of a voluntary motor command
14
Efferent copy participates in ______.
deciphering the mixed information from peripheral receptors, thus reducing the cognitive load.
15
Spindle activity is dependent on ______.
gamma activity, which is dependent on the current descending motor command.
16
According to the equilibrium point hypothesis, motor command to a muscle can be described as a ______.
fixed force-length characteristic (the tonic stretch reflex characteristic)
17
Motor command to muscle allows only certain combinations of muscle force and length to occur in a static state and solves _____.
half the problem of muscle force and length perception.
18
A motor command may be associated with_______.
two characteristics on the force-angle plane.
19
The first characteristic that the motor command may be associated with corresponds to a ________.
chosen value of the central command (the efferent curve)
20
The second characteristic that the motor command may be associated with corresponds to a ______.
certain level of activity of proprioceptors (the afferent curve)
21
The intersection of the characteristics associated the motor command defines _________.
current values of muscle length and force.
22
Kinesthetic perception is based on ____.
signals from proprioceptors.
23
Each proprioceptor provides information that by itself is ______ to extract values of joint angles or torques.
insufficient
24
the combined information is ______.
sufficient
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