Infancy Notes

Infancy: Utero - 2 Years

1. Growth & Development

a. Conception to Birth:

• Rapid cell division leads to embryonic development.
• Organogenesis occurs during weeks 3-8; this is the development of the organs.
• Fetal period: growth in size, weight, and organ function.
• Average birth size: approximately 7.5 lbs, 20 inches.

b. Birth to Age 2:

• Triple birth weight and double height by 2 years.
• Cephalocaudal: Head to toe development (head control before walking).
• Proximodistal: Center to limbs (trunk control before fingers).

c. Factors Impacting Growth:

• Maternal nutrition.
• Exposure to teratogens (e.g., alcohol, smoking, drugs).

2. Phases & Stages Theory

a. Phases During Infancy:

• Reflexive Movement Phase: Basic survival reflexes.
• Rudimentary Movement Phase: Voluntary movements like crawling, grasping.

b. Stages:

• Reflexive:
  • Info encoding (reflexes dominate).
  • Info decoding (voluntary control begins).
• Rudimentary:
  • Precontrol (basic motor control begins).

3. Dynamical Systems Theory (Example: A baby learning to crawl)

• Task: Crawling across the floor.
• Individual: Muscle strength, body size.
• Environment: Carpet vs. hardwood surface.

4. Motor Skill Recommendations

• Provide tummy time for neck/trunk strength.
• Allow safe, open floor space for movement.
• Offer graspable toys to encourage fine motor skills.
• Avoid restrictive devices (e.g., long-term use of walkers).