Motor Development

Biological Mechanisms

• maturation of the CNS

  • growth of the brain and spinal cord

• myelination

  • increases the speed and coordination of motor responses

• reflexes

Environmental and Experiential Influences

• practice and learning

  • motor skills improve with use and repetition

• cultural practices

  • infants in some cultures walk earlier due to swaddling or massage routines

• opportunities for movement

  • tummy time encourages strength and coordination

Dynamic Systems Theory (DST)

• motor development is not pre-programmed but comes from interactions between neurological maturity, body movement capacity, environment, and the task itself

Stages of Motor Development — Gross Motor Skills

• gross motor skills - large muscle activities

  1. newborn reflexes

  2. lifting head (1 month)

  3. rolling over (3 - 4 months)

  4. sitting (5 - 7 months)

  5. crawling (6 - 10 months)

  6. standing without support (9 months)

  7. walking independently (10 - 14 months)

Stages of Motor Development — Fine Motor Skills

• fine motor skills involve small muscle coordination

  1. grasping reflex (birth)

  2. voluntary grasp (4 - 5 months)

  3. pincer grasp (8 - 12 months): thumb and finger coordination

  4. hand-eye coordination improves gradually: ex. stacking blocks, feeding with spoon

Maturational Theory of Development

• development unfolds in a fixed sequence determined by genetics

• environment can support but not change the natural timeline

Dynamic Systems

• emphasizes interaction between multiple systems (neurological, muscular, environmental)

• development is nonlinear and driven by self-organization

Ecological Theory of Development

• infants perceive affordances (possibilities for action) in their environment

• perception guides movement; exploration builds motor skill

Primitive reflexes

• means automatic responses to stimuli

  • rooting—touch cheek→baby turns head, opens mouth— disappears at ~3 weeks

  • stepping—feet on surface→stepping motion—disappears at ~2 months

  • grasping—finger in palm→baby grasps tightly—disappears at ~3-4 months

  • sucking—finger/object in mouth→rhythmic sucking—disappears at ~4 months

  • moro—sudden movement/sound→flailing arms— disappears at ~6 months

  • babinski—stroke foot→toes fan out—disappears at ~8-12 months

What is soft assembly?

when infants combine abilities differently depending on the task or context