Development of motor control 7215 - Tagged

Development of Motor Control

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.

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).

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.

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.

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

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).

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.

Involves biomechanical factors, achievement of milestones, and patterns of movement.
Some relevant reflexes need consideration.

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

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.