Exam 3 Motor Development

Balistic Skills

• motor skill you do fast and with a lot of force

• apply a force to an object in order to project it

Ex. kicking, throwing, battting

Implement

equipment or tools used to apply force

Ex. bat, paddle, or hands

Characteristics of Ballistic Skill

acceleration, on target, movement

Gauging Throwing Skills

Product Measures or Process Measures

Product Measures

• quantitative/ based ‘outcome’ of skill performance

• accuracy, distance, velocity

Process Measures

-qualitative/ how the skill is performed

• development sequence/ movement pattern

Forms of Throwing

1. sidearm

2. one-hand underhand

3. two-hand underhand

4. one-hand overarm

5. two-hand overarm

Most Common= one-handed overarm throw

Three Stages of Throwing

1. Preparatory Phase

2. Execution Phase

3. Follow Through

Characteristics of early overarm throwing

• mostly arm action

• elbow pointed up

• no trunk rotation

• no stepping

• executed by only elbow extension

Characteristics of Proficient Throwing

• Use prepartory movement

  weight shifts, trunk rotates back, arm makes circular downward swing

• Opposite leg, long step

• Differentiated trunk rotation (pelvis rotates, then trunk)

• Upper arm and forearm legs

• Movements are sequential

Developmental Changes in Overarm Throwing: Trunk Action

1. None or forward backward movement

2. Block Rotation

3. Differentiated Rotation

Developmental Changes in Overarm Throwing: Backswing of Arm

1. No backswing

2. Shoulder Flexion

3. Circular, Upward back swing

4. Circular, downward

Developmental Changes in Overarm Throwing: Foot Action

1. No step

2. Homolateral step

3. Short Contralateral step

4. long contralateral step

Developmental Changes in Overarm Throwing: Upper Arm

1. Oblique

2. Aligned but Independent

3. Lagging

Developmental Changes in Overarm Throwing: Forearm Action

1. No lag

2. Lag

3. Delayed Lag

Block

simultaneous rotation of pelvis and trunk

Differentiated

lag

Progression in Childhood Throwing

Body Component analysis shows…

• sane developmental step not achieved at same time for each body component

• hit milestones at different milestones

Differences between Sexes Throwing

• Boys are more advanced in their throwing skills than girls as young as age 3

• Boys develop a mature upper arm pattern than girls by 7th grade

Throwing in Adulthood

• moderately advanced steps

• moderate ball velocities

• differences between sexes

  Musculoskeletal constraints might influence movement patterns used

Changes in Older People's Movements Patterns

• decline in performance

• increase variability

• slowing in movement ( related to control)

Throwing for Accuracy

• may use lower developmental steps for accurate throws than forceful throws

• depends on task constraints

Kicking

• Performer strikes ball with foot

• The ball can be stationary or moving

• Must have perceptual abilities and eye-foot coordination to make contact

• Kicking a moving ball= very difficult for children

• Kicking is considered open kinetic chain

Early Characteristics of Kicking

• no step is taken with a nonkicking leg

• kicking leg pushes forward

• no trunk rotation

• arms are stationary

Characteristics of Proficient Kicking

• Preparatory Wind Up

  trunk is rotated back, kicking leg cocked, knee bent

• Forward trunk rotation

• Movement is sequential

• Arm opposition

Punting

a more complex form of kicking when the ball is dropped

punting is more difficult than kicking for children

Characteristics of Early Punting

• The ball is tossed up rather than dropped

• Punter often contacts the ball with toes rather than instep

Characteristics of Proficient Punting

• Arms are extended to drop ball early from chest height

• Arms then drop to sides and move in opposition to legs

• Punter leaps onto supporting leg, swings punting leg up to make contact

• Punting leg is kept straight; toes are pointed

Sidearm Striking

Ex. tennis, pickleball, baseball

• Various body parts or implements are used

• considered difficult for young children

• mechanical principles are similar for all striking tasks

Characteristics of Early Sidearm Striking

• chopping motion

• elbow extension

• little leg or trunk movement

• child faces the object they are striking

Characteristics of Proficient Sidearm Striking

• Sideways preparatory stance/ long step

• Differentiated trunk rotation

  -allows for a larger swing

• Horizontal swing through a large ROM

• Sequential movements

Developmental Changes in Sidearm Striking

• Sequences for foot and trunk in overarm throw can be used

• Trend is toward use of trunk rotation

  NONE then BLOCK then DIFFERENTIATED

• Plane of swing progresses from vertical to horizontal

• Grip changes from power grip to shake-hand grip

• Elbow are now held away from body and extended before contact

Overarm Striking

Ex. tennis or volleyball serve

• Without an implement (volleybal serve)

• With an implement ( tennis serve)

Characteristics of Early Overarm Striking

• Movements look much like early overarm throwing

• Stationary feet (homolateral)

• Limited trunk rotation while striking

• Swing with a collapsed elbow

• Little or no lag with swing forward

Characteristics of Proficient Overarm Striking

• lower and upper trunk rotated more than 90 degrees

• Elbow is held between 90-119 degrees

• Racket lags behind arm in forward swing

• Foot opposite to striking hand steps forward

• Movement is sequential (open kinetic chain)

Old Adult Striking

Study of old and young people golfing

Uses an iron because it does not require maximal force

• The older reached peak force earlier in the swing

• Older golfers had better speed of the shot

• Older golfers need to exert more force than younger golfers for the same shot

• just as accurate as the younger golfers

Manipulative Skills

Skills in which an individual handles an object with the hands, fingers, or other body parts (wrist or arms)

Ex. of objects: pencil, toys, bat, racquet

Ex of skills: reaching, grasping, catching

• Requires control of body and object

• harder for kids

What makes human unique in performing manipulative skills?

Brain (memory and sensory functions)

What structural constraints contribute to this uniqueness?

Thumbs

How might these constraints change over the lifespan?

muscle function and brain memory declines

What environmental and tasks constraints influence manipulation of an object?

Sweat, Rain, Humidity

Prehension

the grasping of an object

Reaching and Grasping Approach

Halverson (1931)

• Filmed infants (16-52 weeks) grasping 1 inch cubes

• Transition from power to precision grips, begins at 20 weeks

• defined 10 phases of prehension

  Limitation: only one task and one environmental condition

Discovery found proximodistal pattern of development and discover the gradual increase in movement speed and efficiency with age

Hohlstein (1982)

Replicated Halverson’s study but used different shapes and sizes of blocks

Discovery: object shape and size influences grasps/ by 9 months infants shape hand to match object

Newell (1989, 1993)

-studied 4-8 month infants

-grasping a cube and 3 cubes of different diameters

Discovery: grip scaled with object size like adults but were more variable

Kuhtz- Buschbeck

• analyzed kinematics of reach to grasp movements in 10 healthy adults and children

• varied distance, object size, and visual feedback

Discovery:

- Children open their hands wider than adults

-Children rely on vision for reaching

-grip formation is not mature by 6-7 years

-children are more variable in their reach-to-grasp

3 Principles of Prehension

1. depends on individual, environmental, and task constraints

2. movements refine overtime as we age

3. grip depends on size and shape of an object and visual information