Movement Production and
Motor Programs
Chapter 4
Objectives
Understand the concept of open-loop
control for movement
Describe the rationale for and
characteristics of motor programs
(continued)
Objectives (continued)
Understand how people might use
generalized motor programs to
produce various versions of a
particular type of movement,
including versions they have never
attempted previously
Apply the principles of motor
programming to practical
performance situations
Preview
How can we explain how skilled
athletes produce so many
movements with correct sequencing
and coordination so quickly that the
movements seem like one fluid
action?
How do athletes control the
individual components and combine
them to form a whole movement?
How does it all happen?
Overview
Concept of open-loop control and
motor programs
Motor programs used with various
reflex pathways
Concept of the generalized motor
program and its flexibility
Open-Loop Control
Executive
Effector
No comparator or feedback
Quick
No error detection
No modifications during movement
Open-Loop Characteristics
Advanced instructions
Advanced sequencing
Can’t modify
Examples of open-loop control
- Quick, forceful movements
- Kicking, throwing, batting
Motor Programs as Open-Loop
Control Systems
The stages of processing are used to
develop the motor program by
determining the action to be
initiated.
With practice, a program is capable
of controlling longer sequences of
action, and movements become
more elaborate.
(continued)
Motor Programs as Open-Loop
Control Systems (continued)
Motor programs are stored in long-term
memory (retrieved when needed) for use
in short-term memory.
Not much attention is needed for
movement once program begins to run.
The better information is learned, the less
time is needed for response programming;
performer can focus on higher-level
cognitive functions.
Support for Motor Programs:
Reaction Time
Reaction time increases when
additional elements are added to the
movement and more limbs are
involved.
When action is more complex,
reaction time is longer and more
time is needed to organize the
system.
Support for Motor Programs:
Deafferentation
After deafferentation (severing the
nerves so CNS no longer receives
sensory information), monkeys could
still respond to lights and carry out
learned motor programs.
Motor program is presumed to be
without sensory information or
feedback.
Support for Motor Programs:
Electromyography
After mechanically blocking a limb
using electromyography, activity is
exactly the same as when limbs are
not blocked.
There is no feedback from the
moving limbs because the limbs can’t
move, yet there seems to be a motor
program.
What Is Necessary
for Motor Programs to Run?
Specific muscles to produce the
action
Order of muscle activation
Force on various muscle
contractions
Timing and sequencing
Duration of contractions
Central Pattern Generator
Centrally located control mechanism
that produces genetic, repetitive
actions; it is triggered by stimulus
Difference between CPG and motor
programs—CPG relates more to
genetically defined; motor program
involves learned activities
Reflex Reversal Phenomenon
Reflex activity produces different
responses to a stimulus, depending on
the phase of the movement.
Role of Motor Programs
Define and issue commands
Organize DF
Make postural adjustments
Adapt reflexes for goal
Dynamical-Systems Perspective
No central program command or selforganization
Motor programs emerge naturally
Problems
With Motor Program Theory?
Novel tasks are not explained.
Storage space is not accounted for.
Solution is generalized motor program
Generalized Motor Program
Suggests that there is a stored
pattern of movement instead of a
specific movement
Allows flexibility to modify the
generalized program to produce
various patterns to meet the
demands of the task