Motor Behavior During Childhood

1. Motor Behavior During Childhood • Laws of motion and stability • Movement governed by principles of motion and stability • Environment influences movement patterns • Growth changes size, proportions • Optimize skill performance based on these laws • Force • Newton’s first law of motion: external force must act on a resting object to cause it to move • Maximize performance: apply force over greatest distance • Optimal Force characterized by: • Preparation • Application of force through full range of motion

2. Action/Reaction • Newton’s 3rd law of motion: For every action there is an equal and opposite reaction • Want to exert as much force as they can • Also applies to parts of the body • Extension of a limb • Ballistic task: limb traces part of circle • Releasing or striking: an object flies away from curved path in a straight line

3. Open Kinetic Chain • Maximal ballistic effort involves several parts in sequence • Sequence must be tied so force of each succeeding movement is applied just after the previous movement to accelerate the object • Force Absorption • Can minimize force by dissipating it over a distance or over area • Increase distance or area to better absorb force

4. Base of support • Larger the base the more stability • Kids start out with wider stance until gain more balance • Skilled: just wide enough to maintain stability • Qualitative changes in motor skills • Skill development:gradual process of refining skills • Many have described development through sets of successive steps • Developmental sequences • Can apply developmental steps in two ways • Describe characteristics for Step 1. • Component model • Sometimes reach transitions

5. Locomotor Skills • Walking • Running • Jumping • Hopping • Galloping • Sliding • Skipping

6. Walking • Acquire near adult walking by age 5 • Walk alone between 9 and 17 months of age • Early walking • Short steps -flat footed • Toes pointed out -knee bent • Wide stance -very little trunk rotation • Hands and arms carried high in bent position • As develop, drop to waist • Later extend arms at sides

7. Proficient Walking • Stride length increase • Heel to forefoot pattern • Decrease in out-toeing, narrow base of support • Double knee lock pattern • Pelvis rotates • Increase in balance • Oppositional arm swing

8. Developmental Changes • Age 2: ingredients for fast walking • Pelvic extension: 14 months • Knee flexion: 16 months • Narrow support: 17 months • Oppositional arm swing: 18 months • Stride length increase through adolescence • Increase velocity: 1-3.5 years • Rhythm and coordination improve up to 5 yrs

9. Observing Walking • Need for practice • Focus on specific body components • One segment at a time • Arm position and opposition • Videotaping from front and side

10. Running • More advanced but similar to walking • Period of flight • Flight phase 6-7 months after learn how to walk • Earliest running attempts are fast walking • Some suffer regression with fear of the new skill

11. Early Running • Rear leg doesn’t extend fully • Arms extend when swing back • Sometimes swing horizontally • Proficient Running • Increase stride length • Fully extend rear leg at push off • Knee bent in forward swing • Eliminate lateral leg movement • Heel-toe landing • Eliminate out toeing and keep narrow base of support • Support leg flexes with weight • Increased trunk rotation • Arms swing forward and back, elbows at right angles

12. Developmental Changes • Above changes with increased size and strength lead to increase speed and time of flight • Most teenagers continue to refine running form • Some adults don't run correctly • May reflect imbalance • Walking and running are symmetrical and involve 50% phasing • Can observe running using same methods as walking