Development of motor control 7215 - Tagged

Development of Motor Control

• Course Code: HRBP 7205

Child Development

Learning Outcomes

By the end of this session, you should be able to:

• Explain early gross motor development in biomechanical terms.

• Discuss key theories of motor development.

• Identify key motor milestones which will assist with assessing neurological development in atypically developing children.

Theories of Motor Development

Maturational Theory

• Development follows a set invariant sequence tightly linked to CNS development.

• Motor development progresses in a cephalocaudal (head to tail) manner and proximal to distal (center of body outward).

• Recent modifications acknowledge variations in the sequence (Adolph et al., 1998) and the contributions of all systems (BLY, 1994).

• Development perceived as a spiral rather than linear process (Effgen, 2005).

Dynamic Systems Theory

• Replaces the maturational view; not a single cohesive theory, but integrates work from many contributors.

• Movement emerges through interactions of internal conditions, the external environment, and specific tasks.

• No single system directs movement; instead, many dynamic, interacting systems contribute.

• Universal milestones (e.g., crawling, walking) learned through adaptation, where movement patterns adjust based on new tasks by exploring various options.

Phases of Development

• Prenatal: From conception to birth

• Neonatal: From birth to 4 weeks

• Infancy: Until the child can exist independently of a caregiver

• Childhood: Until puberty

• Adolescence

• Adulthood

• Old Age

Development Periods

• Weeks From Conception

  • Embryonic (0-8 Weeks):

    • Differentiation of excitable muscle fibers.

    • Innervation from alpha motor neurons.

  • Fetal (9-36 Weeks):

    • Mass "spontaneous" movements (9-10 weeks)

    • Elicitable Moro reflex (9-10 weeks)

    • Respiratory muscle movements (16 weeks)

  • Birth (Around 40 Weeks):

    • Assistive role in the birthing process.

  • Neonatal (First Month):

    • Elicit reflex walking, crawling, swimming movements, and ocular pursuit movements.

    • Onset of voluntary control.

  • Infancy (4 Weeks to 2 Years):

    • Development of voluntary control, culminating in standing and walking.

Influences on Child Development

• Genetic Influences

• Environmental Factors:

  • Perinatal factors

  • Postnatal factors

Nature versus Nurture?

• Concept of the "feral child" demonstrates the importance of specific experiences in normal development (critical period).

Postural Control and Motor Development

• Simultaneous development of postural, locomotor, and manipulative skills essential for emergence and refinement of motor skills.

• Immature postural systems may act as constraints on the development of other behaviors (As seen in work by Amiel-Tyszkiewicz & Grenier, 1980).

Principles of Development

• Development is a continuous process that depends on the maturation of the nervous system.

• Sequence of development typically follows a similar pattern for all children but exhibits individual variability.

• Development progresses from repetitive and stereotyped behaviors to individual and volitional actions.

• Transition from mass activity to specific responses.

Gross Motor Skill Development

• Involves biomechanical factors, achievement of milestones, and patterns of movement.

• Some relevant reflexes need consideration.

Chailey Biomechanical Approach

• Biomechanics: The science of the mechanics of living organisms, focusing on levers and arches of the skeleton and muscle/gravitational forces.

• Considerations:

  • Load bearing/base of support

  • Shoulder girdle position

  • Pelvic tilt

Observational Analysis

• Assess picture relative to:

  • Shoulder girdle position (protraction/retraction/neutral)

  • Pelvic girdle posture (protraction/retraction/neutral)

  • Ability to move in/out of posture independently.

  • Approximate estimate of infant's age in months.

Motor Development Milestones

0-3 Months

• Transition from physiological flexion to increased extension.

• Achievement of midline head control/Head righting.

• Forearm propping begins.

• Early asymmetry noted (ATNR) and posterior pelvic tilt to neutral.

3-6 Months

• Development of weight bearing through extended arms when prone.

• Increased stability of trunk, evident in swimming motion.

• Disassociation of head and trunk noted.

• Anterior prop in sitting (5 months) and lateral propping (6 months).

• Weight-bearing through legs is initiated.

6-9 Months

• Achievements:

  • Sits independently from prone

  • Engages in mobile weight bearing

  • Displays object permanence

  • Achieves four-point kneeling and pull-to-stand movement.

  • Engages in exploration of environment with hand release in sitting.

9-12 Months

• Milestones include:

  • Reciprocal crawling

  • Cruising while standing

  • Reduced base of support when sitting

  • Refined movement sequences

  • Protective extension backwards (10 months)

  • Variation in movement patterns introduced.

Righting and Protective Reactions

Righting Reactions

• Optical Righting

• Labyrinthine righting

• Body on Head righting

• Neck on Body righting

• Body on Body righting

Tilting and Protective Reactions

• Further exploration of postural control through integrated movement patterns.