Fundamental Object-Control Skills of Childhood
Introduction:
Once a child can
ambulate without assistance, the hands become free to explore the environment,
allowing for object-control skills to be developed. Object-control skills
include throwing, catching, kicking, punting, and striking.
Throwing:
Throwing is
considered the most complex of the object-control skills, and displays five
stages of development. The most evident changes are that the movement
progresses from an anterior-posterior plan to a horizontal plane, and the base
of support changes from stationary to shifting position.
Ø
1st stage
o
Feet stationary
o
Arm dominated throw
o
Faces direction of intended throw
o
No trunk/hip rotation
Ø
2nd stage
o
Body moves in horizontal plane, instead
of an anterior-posterior plan
o
Segmented motion
o
Feet remain stationary
Ø
3rd stage
o
Lead step is ipsilateral or unilateral to the
throwing arm
o
Elbow flexion seen
Ø
4th stage
o
Lead step is contralateral to the throwing arm
o
High wind up (Arm horizontally adducted in
forward swing)
Ø
5th stage
o
Contralateral step
o
Follow through observed
Figure 1. Immature thrower.
Catching
Catching
involves bringing an airborne object under control using the hands and arms.
Catching has five stages, which is for the two handed catching. One handed
catching exists as well, but it is less successful.
Ø
1st stage
o
Passive movement
o
Feet stationary
o
Palms face upward
o
Minimal, if any, attempt to adjust body or arms
Ø
2nd stage
o
Palms facing each other
o
Elbows slightly bent
o
Ball is trapped against body or “hugged.”
o
Feet stationary
Ø
3rd stage
o
Initial step towards the ball
o
“Scooping” of the ball is seen
Ø
4th stage
o
Use of the hands to catch the object instead of
the body
o
Hand-eye coordination present
Ø
5th stage
o
Entire body adjusted to control the object with
only the hands
o
The elbows are flexed to absorb the shock
Figure 2. Palms facing each other as infant catches ball.
Kicking
Kicking
is a form of striking but with your foot. Place kicking involves the ball being
stationary during the approach of the kick, and is differentiated by the level
of kicking skills.
Beginner level kicker
Ø
May only push the
ball forward with their feet or not pull their leg back before kicking it
Ø
No follow
through
Intermediate level kicker
Ø
Some flexion of
the knee and
Ø Backswing present
Ø Arms elevated
Ø
Some follow
through but not as complete as an advanced kicker.
Advanced level kicker
Ø
Running start
Ø Leap step onto support foot prior to striking the
ball
Ø Kicking leg flexed at the knee and
hyper-extended at the hip
Ø
Foot thrust
forward to strike the ball
Figure 3. Child runs up to ball and pauses.
Punting
Punting is different from kicking because it a) uses a ball that’s always stationary and b) is a more complex process. Three components of punting include the ball release arm component, ball contact, and leg action component. There are also four stages of punting.
Ø
Stage 1
o Stationary
preparatory position
o Ball
is held with both hands
o Flexion
at the hip and knee of punting legs
Ø
Stage 2
o
Stationary during preparatory phase
o
Ball held in both hands and usually dropped
forward or upward
o
Non support leg flexed at the knee
o
Generally the force created is upward, causing
performer to take step backward after the strike
Ø
Stage 3
o
Performer moves forward for one or more steps in
preparation for the punt
o
Ball generally released in forward and downward
direction
o
Follow through of the punting leg will carry the
punter ahead of the point where the ball was hit
Ø
Stage 4
o
Punters approach is rapid, one or more steps
then usually ends in a leap just prior to contact
o
Ball is contacted at or below knee level
o
Momentum of the swinging leg carries the
performer off the surface in an upward and forward direction
Figure 4. Stage 4 punter.
Striking
Striking
involves some sort of contact with an object with either one of your hands,
both, or a tool such as a racket.
Inexperienced
Striker
Ø
Arms up and flexed
Ø
Upward-downward
swing
Ø
They may take a step
forward once with the same arm they are striking with
Advanced
Striker
Ø Swing becomes more horizontal
Ø Contralateral step
Ø
Trunk rotation
added onto motion.
Figure 5. Use of the hands as the striking implement.
Applied Section
Knowledge
of the object control skills has some important application to our future work
in the medical field. By understanding the normal from the abnormal
development, we can properly intervene and potentially solve the dilemma with
the proper intervention. Although it will be difficult to prescribe treatment
due to the many constraints, knowledge of the object control skill will aid us
to the right diagnosis.
Possible
constraints we may be looking for includes:
Ø
Ball size
Ø
Ball velocity
Ø
Instruction
Ø
Knowledge and experience of the skill
With the
proper diagnosis we could find ways to help a developing child become strong
enough to perform these tasks. Also, in order to test for certain diseases and
disorders, a child could be assessed using some of these skills.
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