Motor Development
Introduction to Motor Development
This section introduces the concepts and objectives of motor development as outlined by Dr. Minahan, emphasizing two main objectives:
Describe typical motor development in children up to five years of age.
Discuss the interaction between task, environment, and the individual child in relation to motor development.
The Role of the Neurological System in Motor Development
Motor development is fundamentally reliant on the gradual maturation of the neurological system, but other bodily systems significantly contribute to movement and motor skills. Key points include:
Immature Neuromuscular System: Initially, motor development hinges on reflexive responses where sensory stimuli trigger motor actions.
Active Participation: Children learn motor skills through interaction with their environment; experiences and situational influences facilitate this learning.
Opportunity for Skills: Essential developmental skills, such as walking, require sufficient opportunities and safe environments for practice. For instance, a child's chances to crawl or walk diminish if they are confined to a crib without adequate floor time.
Theories of Motor Development
Motor development theories can be categorized into several schools of thought:
Nature vs. Nurture
Nature Theorists
Propose that the brain is the primary engine of development, operating based on pre-established genetic frameworks.
Stress the importance of central nervous system (CNS) maturation, adhering to a biological time clock, where monitoring growth can involve tracking the emergence and disappearance of reflexes as milestones.
Nurture Theorists
Argue that environmental factors primarily shape motor development.
Emphasize that learning and reinforcement are pivotal, as movements are generated from processed sensory input rather than simply reflexive actions.
Systems Theory
The most contemporary approach posits that behavior is constructed from multiple interacting components.
It views movements as flexible and adaptive, similar to improvisation in acting or music, where various skills and inputs combine based on context and individual developmental history.
This theory introduces the concept of "rate limiters": systems that develop at differing rates, thereby influencing overall motor skill acquisition.
Importance of Exploration in Learning
Child exploration plays a vital role in motor development by generating perceptual information which guides future movements. Types of exploration include:
Visual Exploration: Noticing and tracking objects or targets.
Proprioceptive Exploration: Swaying and stepping movements that inform balance.
Tactile Exploration: Using limbs or mouths to probe surfaces or spaces.
Experimentation: Trying unique methods to achieve specific outcomes using various behavioral methods to solve problems.
Development of Specific Movements
Specific milestones in motor development (sitting, crawling, cruising, walking) involve distinct parameters that define their success. Each posture or position presents unique challenges and muscular demands, highlighting that:
Different muscle groups are engaged for balance and propulsion.
Movements yield varying vantage points influencing visual perception, thus requiring calibration of sensory inputs (visual, vestibular, and proprioceptive) for effective performance.
Patterns and Principles in Motor Development
Several foundational patterns characterize motor development:
Cephalic-Caudal Development
Development progresses from head stabilization and movement control (cephalically) towards limb movement control (caudally).
Example: Getting onto elbows while lying prone develops prior to achieving quadruped stance.
Proximal-Distal Development
Stabilization and movement originate within the body's core before extending outward to fingers and extremities (distal movement).
Example: Shoulder stabilization is necessary before achieving fine grasping abilities.
Gross Motor Before Fine Motor
Fundamental gross motor skills must be established prior to mastering fine motor skills.
Example: A child learns to hold an object with two hands before progressing to a one-handed grasp.
Flexor-Extensor Dynamics
Typically, a child displays flexor movements prior to extensor movements, and extensor (anti-gravity) movements develop before complex flexor movements.
Biological Maturation in Motor Development
The maturation of all related body systems over time plays a significant role in developing motor skills. Specific examples include:
Weight-bearing on flexed joints precedes elbow extension in push-up position, followed later by quadruped movement, which leads to bear walking utilizing extended limbs.
Important Terms and Milestones
Understanding key terminology assists in the discussion of developmental stages.
Full Term: Generally considered within the range of 38 to 42 weeks' gestation, crucial for assessing development in preterm infants.
Various developmental domains exist beyond motor skills, including self-help, problem-solving, social-emotional development, and language.
Gross Motor and Fine Motor Development
Although various developmental aspects are crucial, focus generally leans towards gross and fine motor milestones as they are critical indicators utilized in physical therapy and pediatric assessments.
Motor Milestones and Averages
Rolling (Back to Belly & Belly to Back): Approximately 5 months.
Sitting Independently: Around 7 months.
Creeping on Hands and Knees: About 10 months.
Walking Well: Approx. 14 months.
Running: Starts at around 18 months, although movements may appear clumsy.
Alternating Steps on Stairs: By about 30 months, often with support.
Jumping in Place: Similarly occurs at around 30 months.
Standing on One Foot: Typically develops by age 3.
Hopping on One Foot: Expected by age 4.
Implications of Environmental Context
The realization that environments affect developmental milestones is vital. For example, a child's height relative to the stair's height can significantly limit climbing ability, and stability surfaces influence balance when standing on one foot. Overall, the interconnections between tasks, individual capacities (including perception and cognition), and environmental considerations play crucial roles in shaping movement development.