In-depth Notes on Locomotion and Motor Skills Development
Chapter 6
Key Differences Between Locomotion and Motor Milestones
Motor Milestones:
Early developmental achievements (e.g., lifting the head, sitting up).
Serve as a foundation for further movement skills.
Locomotion:
Refers to the act of moving from one place to another (e.g., walking, crawling, running).
Emerges after motor milestones are achieved.
Reasons for Preferential Use of Walking
Stability and Balance:
Walking is the most stable and balanced form of locomotion.
Energy Efficiency:
Requires less strength and energy than running or jumping.
Crawling vs. Creeping
Creeping:
Moving on hands and knees with stomach off the ground.
Crawling:
Moving on hands and stomach(chest/stomach touching ground)
Child Development and Movement
Development of Running on All Fours:
Influenced by environmental constraints that make knee support uncomfortable (e.g., rough surfaces).
Reinforcement from caregivers, and above average strength of the infant
Lifespan Changes in Walking:
The timing will not change over the lifespan
50% phasing between legs (left leg is halfway through its movement, the right begins).
But the speed of steps (faster or slower) and the placement (step height or length) can change in relation to structural and environmental constraints.
Age 4: Advanced walking develops (better balance & coordination).
Notable changes post age 60 (e.g., shorter steps, slower speed, increased toe-out).
Comparing Early and Proficient Walkers
Early Walker Characteristics:
Arms in high guard, feet wide and toed-out feet, short steps, and no trunk rotation.
Maximizes stability and balance over mobility (rate controllers: strength & balance).
Proficient Walker Characteristics:
Arm swing in opposition, increased stride length, reduced base of support, pelvic rotation.
Trades off stability for mobility.
Changes in Older Adulthood and Preventive Measures
Changes in Walking:
Shortening of step length, increased toe-outing, decreased speed, reliance on support for balance.
Prevention Strategies:
Regular exercise to enhance strength and balance.
Use of assistive devices when necessary.
Maintenance of joint mobility.
Key Distinction Between Walking and Running
Flight Phase:
Running includes a flight phase where both feet are off the ground, whereas walking maintains contact with the ground.
Look for airborne moments to differentiate between fast walking and running.
Rate Limiters for Walking and Running
Walking Limiters:
Balance and muscle strength.
Running Limiters:
Strength and balance.
Observing Developmental Stages in Running
Intermediate Stage Indicators:
Flight phase present, but arm swing across the chest indicates development still in progress.
Proficient runners have an arm swing in opposition to leg movement.
Hopping vs. Leaping
Hopping Definition:
Taking off from one foot and landing on the same foot.
Leaping Definition:
Taking off from one foot and landing on the opposite foot.
Expected Age for Starting Hopping
Age of Development:
Typically starts after age 3 due to the complexity of balance and strength required.
Rate Limiters for Hopping
Key Factors:
Ability to balance the body on one leg and generate force to facilitate repeated hops.
Development of Skipping
Late Development Reasons:
Involves complex coordination of arms and legs; develops after strength and balance are established.
Limited by coordination rather than strength or balance.
Influential Constraints in Ballistic Skill Learning
Task Constraints:
Most impactful as they dictate the rules, size of objects, and equipment affecting skill learning and performance.
Assessing Throwing Skills
Assessment Methods:
Product Measures:
Evaluate outcomes such as accuracy, distance, and ball velocity.
Process Measures:
Focus on movement patterns and developmental sequence.
Early Throwing vs. Proficient Throwing
Early Thrower Characteristics:
Relies on arm action solely; minimal coordination with trunk or legs.
Proficient Thrower Characteristics:
Incorporates weight shift, trunk rotation, well-timed elbow extension, and follow-through.
Developmental Sequences in Accurate Throws
Choosing Lower Sequences:
More control in lower sequences aids accuracy; throwers may reduce power focusing on precision.
Similarities in Throwing Long Distances
Minimal Differences Among Throws:
Long throws require maximum force, leading individuals to employ their best movement pattern, resulting in similar appearances.
Highest Level of Development for Skills
Variability in Achievement:
Not everyone reaches the highest developmental steps due to differences in physical ability, motivation, opportunity, or environmental support.
Identifying an Early Kicker
Indicators of Early Kicking:
No step taken with the non-kicking leg, forward-kicking leg motion, bent knee at ball contact, no trunk rotation, still arms.
Differences and Similarities Between Kicking and Punting
Similarities:
Striking a ball with the foot requires coordination and timing.
Differences:
Kicking involves a stationary or rolling ball; punting requires dropping the ball from hands before contact.
Proficient Side Arm Striking Movements
Characteristics of a Proficient Striker:
Sideways preparatory stance, long step, differentiated trunk rotation, extended arm before contact, sequential body movements.
Importance of Differentiated Rotation in Trunk
Definition of Differentiated Rotation:
Upper and lower trunk rotate at different times, adding power to movements (e.g., throwing, striking).
Significance of Lag in Ballistic Skills
Lag Mechanism:
Stores energy to be released at the right moment, increasing force and speed in athletic movements.
Skill Execution Before Assessment
Execution Frequency:
Skill should be performed five times for assessment; majority of performances (3 out of 5) must match the developmental level for rating.
Impact of Injury on Bimanual Manipulation Development
Developmental Patterns Post-Injury:
An injury such as a broken arm during critical developmental phases can impact the typical progression of bimanual manipulation skills.