fundamental object-control skills of childhood · 1/13/2011 · fundamental skill ~ object-control...
TRANSCRIPT
Fundamental Object-
Control Skills of
Childhood
Chapter 13
When the child is able to
ambulate freely, the hands
are free to use in a new
fundamental skill ~ object-
control
Overarm Throwing
• One of the most complex fundamental
movements
• Can be divided into 3 phases
– Preparatory phase
• All movements directed away from the intended
line of projection
– Execution phase
• All movements performed in the direction of the
throw
– Follow-through
• All movements following the release of the
projectile
Developmental Stages of Throwing
• Langendorfer (1980)
In Step 2, note how the ball is brought up beside the head with upward humerus flexion and exaggerated elbow flexion
Notice the lack of a preparatory backswing in Step 1
Developmental Stages of Throwing
Option 1 is a circular overhead preparatory Movement with elbow extended
Option 2 is a preparatory phase using a lateral swing backward
Step 3
Developmental Stages of Throwing
By the 2nd grade, boys use Step 4
Option 3 uses a simple vertical lift of the throwing arm
Step 3
Developmental Stages of Throwing
• Throwing motion is posterior-anterior in direction
• Feet do not move
• Little trunk rotation
• Force for projecting the ball comes from hip flexion,
shoulder protraction, and elbow extension
Stage 1
Developmental Stages of Throwing
• More rotation of the body
• Performer may step forward (ipsilateral or contralateral
pattern)
• Arm brought forward in transverse plane
• Form resembles a sling
Stage 2
Developmental Stages of Throwing
• Note the ipsilateral arm-leg action
• Ball is placed into throwing position above the shoulder by a vertical and posterior motion of the arm at the time that the ipsilateral leg is moving forward
• Little or no rotation of the spine and hips
• Follow-through includes flexion at the hips and some trunk rotation
Stage 3
Developmental Stages of Throwing
• Movement is contralateral
• Little or no rotation of the hips and spine during wind-up
– Motion of trunk and arms resembles stages 1 and 3
• Stride forward with contralateral leg provides a wide base
of support and stability
Stage 4
Developmental Stages of Throwing
• Mature movement pattern
Stage 5
Age at which 60% of boys and girls are able to perform at a specific level
Factors that Influence Overarm
Throwing Performance
• Instruction
• Does instruction facilitate development or
is improvement due to the year-to-year
improvement of the fundamental skill?
– Instruction significantly affects changes in
throwing technique, but not greater horizontal
ball velocities
• Velocity should not be used as the sole
index in the evaluation of the over-arm
throw
Factors that Influence Overarm
Throwing Performance
• Knowledge
– Awkward throwers possess significantly less declarative knowledge than more talented throwers
– Awkward throwers lack knowledge in
• Ball size
• Stepping forward with the opposite foot
• Throwing low
• Ability to recognize correct form from a side view
• Knowledge of throwing influences performance
Factors that Influence Overarm
Throwing Performance
• Instructional cues – Identification of critical cues facilitates
throwing performance
• Critical cues – “Take a long step toward the target with the
opposite foot of your throwing arm”
– “Take your arm straight down, then stretch it way back to make an „L‟ with the arm”
– “Watch the target and release the ball when you see your fingers”
Factors that Influence Overarm
Throwing Performance
• Ball size – When ball diameter is scaled up, a
transitional point is reached where the performer resorts to a less mature throwing pattern in the backswing and forearm components
– As diameter increases, there is a transition from one-handed grasping to two-handed grasping
– Ball size and hand width are important in throwing performance
Factors that Influence Overarm
Throwing Performance
• Angle of ball release – In those using an “arm-dominated” throwing
pattern, the ball is released too early resulting in an upward trajectory (49o)
• May be linked to poor grasp, ball weight, and ball size
– A more mature throwing pattern observed at a 15o angle of release
– Older children release the ball at an angle between 25-28o
Accounting for Gender Differences in
Overarm Throwing
• The greatest gender differences for all
fundamental skills is found with throwing
• Success in distance throwing of boys is
associated with
– Heredity
• Arm muscle mass
– Sociocultural factors
• Male adult in the home
Accounting for Gender Differences in Overarm
Throwing
• By age 9, girls throw only 49% as far as
boys due to differences in
– Grip strength
– Height
– Upper-body strength
Accounting for Gender Differences in Overarm
Throwing
• The best predictors of throwing development in
girls are
– Participation in sport
– Presence of an older brother in the household
• TV watching is negatively correlated with
throwing performance
• The best predictors of throwing development in
boys are
– Father’s sport involvement
– Father-son skill play
Accounting for Gender Differences in Overarm
Throwing
• Can gender differences in throwing be accounted for by factors involving human evolution?
• Perhaps
• Throwing behaviors were more prevalent among men in our early history – Defense
– Hunting
Developmental Aspects:
Two-handed Catching
2-year-old 5-year-old 15-year-old
•Focuses on the
tosser, not the ball
•Maintains a static
position
•Reacts too late
•Can anticipate some of
the ball’s changing flight
pattern
•Can focus on thrower,
ball, and own hands
• Movements are correct,
but are carried out in
slow motion
•Can predict the ball’s
flight
•Carries out preparatory
sequences to catch the
ball
•Movements are
smooth
(Kay, 1970)
Developmental Aspects:
Two-handed Catching
• This 6-year old child
is showing fear in
reaction to a thrown
ball
• Seefeldt speculates
that fear of a
projectile is learned
from earlier failures
Developmental Sequences for
Two-Handed Catching
• Arms are directly in front with elbows extended;
palms facing upward and inward
• Arms and hands attempt to secure the ball by
holding it against the chest
Stage 1
Developmental Sequences for
Two-Handed Catching
• Elbows are slightly flexed
• Arms encircle the ball against the chest
• Arm action initiated before ball contact
Stage 2
Developmental Sequences for
Two-Handed Catching
• Child prepares to receive ball with arms flexed and
extended
• Substage 1: child uses chest as first contact point
• Substage 2: child attempts to catch ball with hands
Stage 3
Developmental Sequences for
Two-Handed Catching
• Child prepares to receive the ball by flexing the
elbows and presenting the arms ahead of the
frontal plane
• Ball is caught with the hands alone Stage 4
Developmental Sequences for
Two-Handed Catching
• Many children encounter difficulty when they are required
to move toward the object
• Mature catcher “gives” with the catch
Stage 5
Age at which 60% of boys and girls are able to perform at a specific level
Factors That Influence
Catching Performance
• Ball size
• Ball and background color
• Ball velocity
• Trajectory angel
• Vision and viewing time
• Instruction
• Knowledge and experience
• Catching on the run
• Catching with a glove
Striking
• A fundamental movement in which a
designated body part or some implement
is used to project an object
– Bare hand against volleyball
– Baseball ball
– Tennis racquet
Developmental Aspects of
One-and Two-handed Striking
• Inexperienced striker
– No steps taken or step
taken with homolateral
leg
– Up-down striking motion
– Little backswing
– No rotation of trunk or
hip
– Rigid arm; little wrist
snap
• Experienced striker – Forward step with
opposite foot taken
– Full backswing
– Swings implement horizontally
– Trunk and hip rotation
– Coordinated wrist snap
Developmental Aspects of
One-and Two-handed Striking
• Motion is posterior-anterior in direction
• Elbows are fully flexed
• Feet remain stationary
Stage 1
Developmental Aspects of
One-and Two-handed Striking
• Feet are stationary or right or left foot may
receive the weight
• Unitary rotation of hip and trunk
• Bat moves in transverse plane
Stage 2
Developmental Aspects of
One-and Two-handed Striking
• Shift of weight to the front-supporting foot in an
ipsilateral pattern
• Trunk rotation-derotation is decreased
• Bat is swung in an oblique-vertical plane
Stage 3
Developmental Aspects of
One-and Two-handed Striking
• Mature striking pattern Stage 4
Age at which 60% of boys and girls are able to perform at a specific level
Stationary Ball Bouncing
• The inexperienced dribbler slaps at the ball
Stationary Ball Bouncing
• The mature dribbler fully extends the arm
• Retracts the arm when contact is made
• Hand maintains contact with the ball
• Ball is pushed, not slapped
Kicking
• Performer is usually near the ball
• Thigh of kicking leg moves forward
• Knee extension occurs after contact
Stage 1
Kicking
• Hyperextension at hip and flexion at knee
• Kicking leg moves forward with knee flexed
• Arm-leg opposition occurs during kick
• Force of kick usually not sufficient to move the body forward
Stage 2
Kicking
• One or more steps taken on approach
• Kicking foot stays nears surface as it
approaches ball
• Knee begins to extend prior to contact
• Arm-leg opposition
Stage 3
Kicking
• Mature kicking pattern
• Running start
• Last step taken involves a leap step onto the support foot
Stage 4
Age at which 60% of boys and girls are able to perform at a specific level
Punting
• Ball may be held in both hands as the punting foot lifts
forward and upward to push the ball
• Ball may be tossed up; ball may be bounced
• Flexion at the hip and knee from stationary start
Stage 1
Punting
• Stationary start
• Ball held in both hands and dropped or tossed forward
• Nonsupport leg is flexed
• Kicking force is more upward
Stage 2
Punting
• Forward motion
• Ball released forward and downward direction
• Knee flexed at 90 0
• Follow-through will carry punter forward
Stage 3
Punting
• Rapid approach with culminating leap
• Ball contacted at or below knee height
• Momentum of swinging leg carries the punter off the
ground
Stage 4