Lecture 22: Locomotion

Question 1

Locomotion

Answer 1

an activity leading to a change in the location of the body in external space.

Question 2

Examples of locomotion

Answer 2

walking, running, hopping, swimming, flying, crawling, etc.

Question 3

Important characteristics of locomotion

Answer 3

• velocity
• stride length
• relation between the support and swing phases
• relative timing of the extremities (gait)

Question 4

Two different views of Locomotion

Answer 4

1. Motor Programming

2. Dynamic Systems

Question 5

Motor Programming

Answer 5

Central Pattern Generator: hypothetical neural structure that generates a neural activity, activity is transformed into rhythmic muscle activity, leading to rhythmic behavior

Question 6

Dynamic Systems

Answer 6

rhythmicity of locomotion is caused by interaction of neural activity and the periphery

Question 7

Early Views of Locomotion

Answer 7

1. Sherrington

2. Brown

Question 8

Sherrington

Answer 8

• Locomotion was a pattern produced by alternating reflex responses.
• Voluntary movement is a result of modulating reflexes

Question 9

Brown

Answer 9

Rhythmic motor pattern of locomotion was produced by a special neural network(CPG) that could produce activity even in the absence of reflexes

Question 10

A CPG is

Answer 10

a hypothetical structure in the central nervous system that can generate patterned (rhythmical) activity

Question 11

CPG can be driven by _______ as well as by peripheral information

Answer 11

“Higher” centers

-Both sources of information can lead to gait changes

Question 12

CPG involves ______ types of cells.

Answer 12

three

Question 13

CPG: Cells of two types act on each other and ________.

Answer 13

suppress each other’s activity.

Question 14

CPG: Cells either fatigue quickly or turn off after a brief period of activity, allowing _____.

Answer 14

the other group to be released from inhibition and take over.

Cycle continues until an external influence turns off both groups of cells.

Question 15

Neurons of the 3rd group provide ___________.

Answer 15

input that can both excite and suppress the cells of the 1st two groups

Question 16

Problems w/CPG: ______ higher center

Answer 16

Undefined

Question 17

Problems w/CPG: ______ input could change the pattern of gait activity

Answer 17

Peripheral

Question 18

Problems w/CPG: Difficult to determine if changes in ____ are produced by higher center or peripheral input.

Answer 18

gait

Question 19

Problems w/CPG: Many important variable lack _____.

Answer 19

a good definition

Question 20

Problems w/CPG: This drove the development of _____.

Answer 20

dynamic systems approach

Question 21

Stimulating _____ of cats led to rhythmic moments of the cat’s limbs

Answer 21

reticular formation

Question 22

Different levels of stimulation could _________ locomotion.

Answer 22

slow down or speed up

Question 23

Locomotor Strip is in the ____.

Answer 23

upper cervical region of the spinal cord

Question 24

________ of certain brain areas can induce locomotion

Answer 24

Electrical Stimulation

Question 25

______ changes with the strength of the stimulation.

Answer 25

Gait

Question 26

Locomotion and gait changed can also be induced by ______.

Answer 26

treadmill motion and by intraspinal drugs

Question 27

________ locomotion can be see.

Answer 27

Fictive

Question 28

Graham Brown v. Sherrington: The spinal is likely to contain one, two, to even four _________.

Answer 28

Central Pattern Generators

Question 29

Graham Brown v. Sherrington: A CPG can be driven by _____.

Answer 29

descending and ascending signals.

Question 30

Graham Brown v. Sherrington: It does not necessarily require _____.

Answer 30

either signal

Question 31

Graham Brown v. Sherrington: It can produce ____.

Answer 31

different gaits

Question 32

Dynamic Systems Approach is a system for:

Answer 32

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.

Question 33

______ better explains issues of stability (particularly in M/L direction)

Answer 33

Dynamic Systems Approach

Question 34

Dynamic Systems Approach succeeds in describing ______.

Answer 34

inter-limb and inter-joint coordination

Question 35

DSA: The equations developed by this approach can describe these rather ____.

Answer 35

complex changes in behavior.

Question 36

Motor Programming lacks ___.

Answer 36

coordination, all details of coordination are delegated by the ultimate controller

Question 37

Dynamic Systems: coordination can emerge without supreme problem solved, but it lacks_____.

Answer 37

control

Question 38

What happen when there is a combination of motor programming and dynamic systems?

Answer 38

All elements are linked and there is an upper neural structure that can send descending signals.

Question 39

In M/L direction, COP shifts _______.

Answer 39

towards the stepping foot and then shifts back toward supporting foot.

Question 40

In A/P direction, COP shifts ______.

Answer 40

backward

Question 41

Corrective stumbling reaction occurs during _______.

Answer 41

locomotion

Question 42

Corrective stumbling reaction can be induced by _____.

Answer 42

a mechanical stimulus to the foot.

Question 43

Corrective stumbling reaction represents a _______.

Answer 43

complex pattern of EMG changes

Question 44

Corrective stumbling leads to _____.

Answer 44

a quick step over the obstacle.