This paper relates classic research on motor control and
learning (Kugler, Kelso, & Turvey, 1980, 1982; Newell,
1985) to the needs of practitioners in the field of physical
education. Both theoretical and experimental research on motor
learning has found that the human neuromuscular system is
organized in a particular way so as to meet the difficult
biomechanical, task, and environmental challenges in performing
sport and exercise activities such as are commonly taught
in physical education classes.
Research has shown that the human neuromuscular system meets
these demands by using the separate processes of coordination
and control to produce skilled action. One important goal
of physical education teachers is to facilitate the process
of learning skilled movement in their students. To accomplish
this, some knowledge about coordination, control, and skill
can be helpful.
In motor tasks that involve relatively few segments of the
body there are relatively few demands for coordinating the
many degrees of freedom of the body. However, in whole-body
tasks (i.e., playing basketball, baseball, soccer, etc.),
such as are typically learned in physical education classes,
the human nervous system is faced with the challenge of how
to coordinate the many segments of the human body in a way
to optimally meet what can be challenging task demands.
When a basketball player gracefully fakes out an opponent,
spins and hits a jump shot, there are precise demands for
the coordination of the body in such a way as to pass the
defensive player and shoot the ball so as to pass through
the hoop. Learning abilities such as this require the ability
to coordinate and control the body so as to produce skillful
action that will achieve the objective (i.e., making a basket).
Degrees-of-Freedom Problem
A central problem in the control of human movement is how
the nervous system can control the many joints, muscles, neurons
etc. For example, it can be difficult to simultaneously rub
your stomach and pat your head at the same time. Or, performing
a polyrhythm of tapping twice with one hand while tapping
three times with the other (such as in drumming) is generally
difficult to perform without practice.
These examples show the difficulty that can exist in controlling
only a couple of small segments of the body. It is an even more
challenging proposition to control the human body in sports
that involve the entire body and have strong timing and positioning
demands. Even with the level of computer technology existing
today the movement abilities of which robots are capable is
nowhere near the level of skill in movement that humans display.
Coordination
The process of human motor learning essentially consists in
learning how to master the many redundant degrees of freedom
in the human neuromuscular system so as to optimally meet
the task demands in a given set of environmental conditions.
The first aspect of this process is that of organizing the
coordination between body segments. The nervous system simplifies
the control of the neuromuscular system by constraining different
parts of the body to work together. This constraining of body
segments to act together is performed by coordinative structures,
also known as synergies,
and is called coordination. This simplification of
control is similar to the way the two front wheels of your
automobile are constrained to act together. Because of this,
you only need control one steering while, rather than two.
Because coordinative structures simplify control the result
is that coordination pattern are highly consistent. For example,
when throwing a baseball, each person has learned a pattern
of relative timing between shifting their body weight over
his or her legs, which is timed with respect to rotary,
flexion
and extension
movements of the trunk, shoulder, elbow, etc. The relative
timing of each of these parts of the body is quite consistent.
Learning how to produce such consistent movement patterns
is the process of coordination.
Control In order to meet task demands these coordination
patterns may need to be scaled up or down (such as when throwing
a ball closer or farther away). It can also be important to
throw a ball accurately with respect to time and location.
For example, a catcher in baseball may need to throw the ball
to first base while hitting a relatively small target (around
the first baseman's glove) within a very short time window.
The process of adapting coordination patterns to all these
types of task and environmental demands is called control.
Skill
When athletes produce coordination patterns that they can
adapt to meet the demands of the task and environment that
they have to perform in, this is called skill. Skill
may also involve elements such as producing movements that
are efficient; that is, producing a high work:energy ratio.
Skill may also involve elements such as the ability to produce
smooth movements (e.g., 'minimum jerk'). However, in the end,
skill is generally defined by the ability to meet some external
demands (i.e., being able to beat an opponent).
Physical Education
Understanding the processes of coordination and control to
produce skilled action can be important to physical education
teachers because this knowledge can help them better assist
students. Different types of help and information may be needed
to facilitate coordination as opposed to control. Also, during
different stages of the learning process either coordination
or control may be of more importance. Additionally, the ability
to retain and transfer motor learning can be different with
respect to coordination and control. Knowing this can enable
physical education teachers to better facilitate learning
in their students.
In sporting events that involve multiple degrees of freedom,
feedback from an instructor regarding performance (kinematic
and/or kinetic)
will likely be necessary in addition to feedback regarding
the results of his or her performance (Newell & Walter,
1981; Newell & McGinnis, 1985; Newell et al., 1985). Different
types of augmented information are likely necessary during
different stages of the learning process. Information regarding
knowledge of performance (KP) is more likely to be beneficial
in the early stages of learning (coordination), while knowledge
of results (KR) is more beneficial in later stages.
Early in the learning process physical education teachers
can provide information to facilitate the process of learning
optimal coordination patterns (KP). This type of information
may regard what is called moving with good 'form.' While some
coordination patterns can be identifiable as being good or
bad form, it is also worthwhile to keep in mind that (due
to different properties of each person's body and nervous
system) what is the optimal coordination pattern for one student
may not be optimal for another.
Later in learning the process of control becomes of greater
importance, as this involves adapting the already-learned
coordination patterns to the task and environmental conditions.
For this reason, providing 'knowledge of results' is more
likely to be beneficial in later stages of learning as these
relate more directly to the process of control.
For example, in the initial stages of learning baseball or
softball pitching the learning of body coordination patterns
may be more beneficial than would be worrying about accuracy.
This represents the learning of coordination, while
later focusing on accuracy reflects the process of control,
which is best done after some learning of proper coordination
patterns has been achieved. Also, the golfer Jack
Nicklaus (1974) has recommended having young golfers practice
the full golf swing and trying to hit the ball a long way
early in the process of learning golf, rather than being concerned
with accuracy early on. While Mr. Nicklaus suggested this
to promote flexibility, this strategy is also consistent with
the need to develop optimal coordination patterns before stressing
the scaling and adaptation of these to develop accuracy.
Another relevant factor is the level of skill that is sought
by each particular student or athlete. If a moderate level
of performance is the goal only a relatively short apprenticeship
in coordination may be necessary before moving on to the process
of improving control. However, to reach a high level of ability,
a more extensive amount of time may need to be spent learning
the optimal coordination patterns necessary before moving
on to hone the ability to control these patterns.
Retention and Transfer of Motor Learning
Retention of motor learning is the degree to which improvements
in performance are kept despite the passage of time, and even
layoffs from practice. Research in motor learning has shown
that the learning of coordination is better retained than
is the scaling of these patterns to meet task demands (i.e.,
control). This fact may also play a role in the teaching strategy
of physical education teachers. For example, if students are
going to be having somewhat long periods of time without practice
it may be desirable to spend more time on the process of coordination,
which will be better retained than practice focusing on control.
It has also been found that the need to warm-up before performing
optimally (such as right before a game) affects control more
than it does coordination. For this reason, warming up before
a competition may better focus on the control and accuracy
of movements while not focusing on the coordination patterns
to be produced.
Transfer of motor learning is the degree to which performing
or learning one task affects performance of another task.
Transfer can be positive, negative or neutral, meaning that
performing one task might either help or hurt (or have no
effect on) one's ability to perform another task.
Research on transfer in motor skills has shown that positive
transfer is most commonly associated with control, while negative
transfer has generally been found to occur when two tasks
involve the use of conflicting coordination patterns. What
this means is that it would not be a good idea to have students
or athletes perform a task involving a different coordination
pattern right before competition (such as playing ping pong
right before competing in tennis). However, over the long
term this type of negative transfer is unlikely to persist
(James & Newell, in press).
Task Constraints
It is important to remember that the processes of coordination
and control operate within the context of the constraints
of the task (sport) to be performed. For this reason physical
educators would be well served to take this into account when
teaching motor skills. In some tasks the definition of skill carefully and specifically considers the coordination pattern to be produced.
For example, in diving, dance, and gymnastics the production
of certain coordination patterns may largely be the objective
of performance, rather than external criteria such as putting
a ball through a hoop. In sports such as these an extensive
amount of time may likely be needed to ensure the development
of the coordination objectives, while there may be much less
need to focus on the control of movements.
Other tasks rely minimally on coordination patterns and depend
much more on control processes. For example, throwing darts
requires the coordination of a relatively small number of
body parts in a highly repetitive fashion. In this type of
task it would likely be more beneficial to focus on control
and accuracy with little concern for coordination.
Summary
The activities and sports taught in physical education classes
generally involve multiple degrees of freedom (i.e., the entire
body). This being the case, students generally will be using
the dual processes of coordination and control to learn skill
in these activities. These distinct processes satisfy different
requirements for the production of skilled physical activity,
and require different types of information for each of these
to be learned.
Knowledge of performance regarding movement coordination
will likely be more beneficial early on in learning. KR facilitates
the control of movements and is likely to be your best bet
later on in learning. However, factors such as the demands
of the activity being learned, the level of skill that the
athlete is seeking to achieve, and how much retention of learning
is needed also need to be kept in mind.
