Physical Development of Children Chapter 13 Physical Development of Children © Gallahue, D.L., Ozmun, J.C., & Goodway, J.D. (2012). Understanding Motor Development. Boston: McGraw-Hill. © 2012 McGraw-Hill Companies. All Rights Reserved. McGraw-Hill/Irwin

Key Concept The Physical Fitness of Children Has Been Assessed Through a Variety of Laboratory and Field-based Measures, and May Be Improved Through the Application of Appropriate Training Techniques

“Fitness” Defined Physical Fitness Is a Positive State of Well-being Influenced by Regular Physical Activity, Genetic Make-up, and Nutritional Adequacy

Components of Health-related Fitness (Table 13.2) Cardiovascular/Aerobic endurance Muscular strength Muscular endurance Joint flexibility Body composition

Cardiovascular/Aerobic Endurance (con’t) Definition: the ability to perform numerous repetitions of a stressful activity requiring considerable use of the circulatory and respiratory systems VO2 Max – the largest quantity of oxygen an individual can consume during physical work while breathing air at sea level Measures of physical activity (activity self-reports, heart rate monitors, accelerometers)

Muscular Strength and Endurance (Table 13.1) Muscular strength: the ability of the body to exert force Muscular endurance: the ability of a muscle or a group of muscles to perform work repeatedly against moderate resistance The Strength – Endurance continuum

Muscular Strength and Endurance (con’t) Types Isotonic Isometric Isokinetic Measures of Strength/Endurance Laboratory: dynamometers Field: sit-ups, push-ups, pull-ups

Muscular Strength and Endurance (cont.) Developmental factors Throughout childhood both boys and girls tend to make steady year-to-year improvements on most measures of muscular endurance with boys only slightly outperforming girls prior to puberty

Muscular Strength and Endurance (cont.) Trainability (resistance training vs. weight lifting) Training results positive: strength enhancement, performance injury reduction, improved performance negative: epiphyseal growth plate injuries

Joint Flexibility Definition: the ability of the various joints of the body to move through their full range of motion Static/Dynamic flexibility (static vs. ballistic stretching) Joint specific

Joint Flexibility (con’t) Developmental factors Girls outperform boys Preadolescent growth spurt (bone growth precedes muscle & tendon growth) Trainability (“use it or loose it”)

Body Composition Definition: proportion of lean body mass to fat body mass Field measures Skin-fold calipers Body Mass Index (BMI) Sedentary lifestyles and obesity

Components of Motor Fitness (Table 13.3) Movement control factors: -balance (static & dynamic) -coordination (gross motor & eye-hand) Force production factors: -movement speed -agility/quickness -power

Coordination Definition: the ability to integrate separate motor systems with varying sensory modalities into efficient patterns of movement Gross motor examples: hopping, skipping, vertical & horizontal jumping Eye-hand & eye-foot examples: bouncing, catching, throwing, kicking Developmentally, gross body coordination and eye-hand and eye-foot coordination appear to improve with age in a roughly linear fashion

Balance Definition: the ability to maintain the equilibrium of one’s body when it is placed in various positions Vestibular apparatus (semicircular canals, otolith, macula) Measures Static: one foot balances, Dynamic: walking board Developmental factors Linear improvements from 2-12 Girls more proficient up to age 7-8

Movement Speed Definition: the ability to cover a short distance in as brief a time as possible Reaction time & movement time Measures: various short distance sprints Developmental factors Improvements occur linearly throughout childhood No gender differences to age 6-7, boys faster at all later ages

Agility/Quickness Definition: the ability to change the direction of the body rapidly and accurately Measures: shuttle runs of various distances Developmental factors Improvements occur linearly throughout childhood boys perform faster at all ages agility performance of the most recent generation declined in almost every age group and for both boys and girls when compared to the scores recorded decades earlier

Power Definition: the ability to perform a maximum effort in as short a period as possible Explosive strength (strength x speed) Measures: vertical jump, long jump, distance throw, velocity throw Developmental factors Linear improvements - early childhood through adolescence in boys, to 13-14 in girls

Concluding Concept Although the Components of Childhood Fitness Can Be Modified Through Training, We Need To Find Ways to Help Children Sustain Increased Physical Activity That Are Both Purposeful and Meaningful