Flashcards in Lecture 22: Locomotion Deck (44)
Loading flashcards...
1
Locomotion
an activity leading to a change in the location of the body in external space.
2
Examples of locomotion
walking, running, hopping, swimming, flying, crawling, etc.
3
Important characteristics of locomotion
-velocity
-stride length
-relation between the support and swing phases
-relative timing of the extremities (gait)
4
Two different views of Locomotion
1. Motor Programming
2. Dynamic Systems
5
Motor Programming
Central Pattern Generator: hypothetical neural structure that generates a neural activity, activity is transformed into rhythmic muscle activity, leading to rhythmic behavior
6
Dynamic Systems
rhythmicity of locomotion is caused by interaction of neural activity and the periphery
7
Early Views of Locomotion
1. Sherrington
2. Brown
8
Sherrington
-Locomotion was a pattern produced by alternating reflex responses.
-Voluntary movement is a result of modulating reflexes
9
Brown
Rhythmic motor pattern of locomotion was produced by a special neural network(CPG) that could produce activity even in the absence of reflexes
10
A CPG is
a hypothetical structure in the central nervous system that can generate patterned (rhythmical) activity
11
CPG can be driven by _______ as well as by peripheral information
"Higher" centers
-Both sources of information can lead to gait changes
12
CPG involves ______ types of cells.
three
13
CPG: Cells of two types act on each other and ________.
suppress each other's activity.
14
CPG: Cells either fatigue quickly or turn off after a brief period of activity, allowing _____.
the other group to be released from inhibition and take over.
Cycle continues until an external influence turns off both groups of cells.
15
Neurons of the 3rd group provide ___________.
input that can both excite and suppress the cells of the 1st two groups
16
Problems w/CPG: ______ higher center
Undefined
17
Problems w/CPG: ______ input could change the pattern of gait activity
Peripheral
18
Problems w/CPG: Difficult to determine if changes in ____ are produced by higher center or peripheral input.
gait
19
Problems w/CPG: Many important variable lack _____.
a good definition
20
Problems w/CPG: This drove the development of _____.
dynamic systems approach
21
Stimulating _____ of cats led to rhythmic moments of the cat's limbs
reticular formation
22
Different levels of stimulation could _________ locomotion.
slow down or speed up
23
Locomotor Strip is in the ____.
upper cervical region of the spinal cord
24
________ of certain brain areas can induce locomotion
Electrical Stimulation
25
______ changes with the strength of the stimulation.
Gait
26
Locomotion and gait changed can also be induced by ______.
treadmill motion and by intraspinal drugs
27
________ locomotion can be see.
Fictive
28
Graham Brown v. Sherrington: The spinal is likely to contain one, two, to even four _________.
Central Pattern Generators
29
Graham Brown v. Sherrington: A CPG can be driven by _____.
descending and ascending signals.
30
Graham Brown v. Sherrington: It does not necessarily require _____.
either signal
31
Graham Brown v. Sherrington: It can produce ____.
different gaits
32
Dynamic Systems Approach is a system for:
movement production, including the central neural structures, effectors and the connections with the CNS, and the environmental forces and sources of sensory information, can be modeled with complex, non-linear equations.
33
______ better explains issues of stability (particularly in M/L direction)
Dynamic Systems Approach
34
Dynamic Systems Approach succeeds in describing ______.
inter-limb and inter-joint coordination
35
DSA: The equations developed by this approach can describe these rather ____.
complex changes in behavior.
36
Motor Programming lacks ___.
coordination, all details of coordination are delegated by the ultimate controller
37
Dynamic Systems: coordination can emerge without supreme problem solved, but it lacks_____.
control
38
What happen when there is a combination of motor programming and dynamic systems?
All elements are linked and there is an upper neural structure that can send descending signals.
39
In M/L direction, COP shifts _______.
towards the stepping foot and then shifts back toward supporting foot.
40
In A/P direction, COP shifts ______.
backward
41
Corrective stumbling reaction occurs during _______.
locomotion
42
Corrective stumbling reaction can be induced by _____.
a mechanical stimulus to the foot.
43
Corrective stumbling reaction represents a _______.
complex pattern of EMG changes
44