Early Motor Development

1
chapter 5

• Early Motor Development

2
Early Motor Behavior

• Can be reflexive or spontaneous (Clark, 1995)
• Reflexive stereotypical response elicited by a
  specific external stimuli
• Spontaneous movements not caused by known
  external stimuli

3
Spontaneous Behaviors

• Assumed to be extraneous movements with no
  purpose
• Similar to mature movements
• Examples
• Spontaneous arm movements and reaching
• Spontaneous kicking and adult walking

4
Infant Kicks
Click image to view video
5
Reflexes

• Reflexes occur quickly after onset of stimuli.
• They involve a single or specific group of
  muscles (not the whole body).
• They resist habituation (at any one time).
• Persistence may indicate neurological problems.

6
Purpose of Reflexes

• Built-in responses facilitate survival.
• They enable open dialogue with the environment.
• Reflexive movements result in sensory
  consequences (adaptation).
• Reflexes provide building blocks for future
  movement.

7
Asymmetrical Tonic Neck Reflex

• Infant starts in supine position.
• Stimulus turn head to one side.
• Response same-side arm and leg extend.

8
Symmetrical Tonic Neck Reflex

• Infant starts in supported sitting.
• Stimulus extend head and neck or flex head and
  neck.
• Response arms extend and legs flex, or arms flex
  and legs extend.

9
Palmar Grasp Reflex

• Stimulus touch palm with finger or object.
• Response hand closes tightly around object.

10
Moro Reflex

• Infant starts in supine position.
• Stimulus shake head (e.g., by tapping pillow).
• Response arms, legs, and fingers extend then
  arms and legs flex.

11
Stepping Reflex

• Stimulus place soles of feet on flat surface.
• Response walking pattern of legs.

12
More Reflexes

• Sucking reflex
• Stimulus touch face above or below the lips.
• Response sucking motion begins.

• Babinski reflex
• Stimulus stroke sole of foot from heel to toe.
• Response toes extend.

13
Constraints

• What constraints exist during the reflexive
  period?
• Structural
• Functional
• Environmental physical
• Environmental sociocultural
• Task goals, rules, equipment

14
Later Infancy

• Gain voluntary control of movements
• Understanding of environment, objects in the
  environment
• Meaningful interactions with others
• Postural reactions

15
Postural Reactions

• Begin at around 4 months
• Help to maintain posture in a changing
  environment
• Initially, similar to reflexes later,
  incorporated into general repertoire

16
Labyrinthine Righting Reflex

• Infant is supported upright.
• Stimulus tilt infant.
• Response head moves to stay upright.

17
More Postural Reactions

• Derotative righting
• Infant starts in supine position.
• Stimulus turn head to one side, or turn legs and
  pelvis to other side.
• Response body follows head in rotation, or trunk
  and head follow in rotation.

• Parachute
• Infant held upright.
• Stimulus lower infant toward ground rapidly.
• Response legs and arms extend.

18
Motor Milestones

• Fundamental motor skills
• Building blocks
• Cumulative, sequential
• Lead to future complex motor skills
• Specific movements that lead to general actions

19
Locomotor and Posture Motor Milestones An Example
Emily at 2 months
(continued)
20
Locomotor and Posture Motor Milestones
(continued)

• 2 months lifts head in prone
• 3 months lifts shoulders (turns head)

(continued)
21
Locomotor and Posture Motor Milestones (continued)

• 5 months rolls over sits unsupported

(continued)
22
Locomotor and Posture Motor Milestones (continued)

• 7 months gets on hands and knees
• 8 months creeps on hands and knees

(continued)
23
Locomotor and Posture Motor Milestones (continued)

• 9 months
• pulls to stand cruises furniture

(continued)
24
Locomotor and Posture Motor Milestones (continued)

• 10 months stands alone
• 12 months walks alone

25
Rate Limiters, or Controllers

• Individual constraints that inhibit or slow the
  attainment of a motor skill
• Rapidly changing during early childhood periods