Chapter 1 Notes
Chapter 1 Notes KIN 360
Popular in Physical Growth and Motor Behavior
Popular in Kinesiology
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Chapter One 01292015 What is Motor Development Why Study It Refers to the continuous age related change in movement as well as the interacting constraints of the individual and environmental factors Who Cares About Motor Development 0 Parents 0 Pediatrics PT and medical Teacherinstructor education Manufactures and designers De ning Motor Development Severalcharacteristics A continuous process of change in fundamental capacity Related to but not dependent on age SequenUalchange Involves change in movement behavior Depends on underlying processes 00000 Other Areas of Development 0 Cognitive Social o Etc Motor Development 0 Development of movement abilities Related Areas of Study 0 Motor learning permanent gains in motor skill capability associated with practice or exposure Motor Control 0 Look on power point 0 The nervous system s control of the muscles to permit skills and coordinated movements 0 Very closely related to motor development a lot overlap Related Terms 0 Physical growth quantitative increase in size of body mass 0 Physical maturation qualitative advance in biological makeup cell organ or system advancement in biochemical composition 0 Aging process occurring with passage of time leading to loss of adaptability or full function and eventually to death Physical Growth 0 Quantitative increase in size or magnitude 0 For humans from conception and to late adolescence Therefore growth and motor development refer to size and funcUonalcapac y Not referring to weight gain or mass gain due to strength training later in life Maturation Progress toward physical maturity the state of optimal functional integration of an individual s body systems and the ability to reproduce Development continues long after maturity is reached Continues and will always be changing until we die Aging Growing older Changes that lead to the loss of adaptability or function and eventually lead to death Constraints Can be viewed as both good or bad Limit or discourage certain movements Permit or encourage other movements Shape movement EX playing soccer in the winter on a pond The ice and weather is acting as the constraint and shaping the movement You will be sliding more and encouraged to pass more It will limit how fast you move up and down the ice BOOK DIAGRAM Newell s Model of Constraints Individual Constraints 0 Inside the body internal 0 Structural constraints related to body s structure 0 Height 0 Muscle Mass 0 Functional constraints related to behavioral function 0 Attention 0 Motivation Environmental Constraints 0 Outside the body properties of the world around us 0 Global not task speci c 0 Physical o Gravity o Surfaces Sociocultural 0 Gender roles EX boys football girls dance 0 Cultural norms EX Canada kids learn to skate before they can walk Task Constraints External to the body Related speci cally to tasks or skills 0 Goal of task 0 Rules guiding task performance 0 Equipment EX dribbling and passing in basketball boundary lines and point values 3 second rule and back court violations Why We Like This Model The interaction of individual task and environment constraints changes the movement over time patters of interaction lead to changes in motor development It emphasizes the in uence of where the individual moves what the individual does task on individual movements as well as the individual structural and functional age related changes Constraints Summary May limit or discourage some movements but at the same time many encouragepermit other movements Individual physical and mental characteristics Structural related to individual s body structure often they change Functional relate to behavioral functions motivation fear experience attention span etc They change more rapidly Try to tell what is effecting movement Environmental exist outside the body as a property of the world around us Newell s Model 0 More global than other models previously used in the study of motor development 0 Accounts for the complexity of the interaction of individual environmental and task oriented How do know it is Change 0 What if the person just got lucky 0 Error in measuring system 0 Picture change by 0 Graphing over time and seeing if a trend is emerging Picturing Change 0 Age on horizontal x axis days weeks months years 0 Measurement of interest on vertical y axis A Paradox in Development Universality individual in a species show great similarity in development Variability individual differences exist Paradox of Universality versus Variability If you had a gym full of preschool aged children what would we see 0 In general many of the same movements but individually many speci c differences 0 Children can arrive at the same point developmentally using different pathways with some above below or exactly average 0 Goal is to take available research to make insightful conclusions and decisions about motor development or individuals and to learn how to obtain and analyze further research information Typical Research Study Designs 0 Longitudinal 0 An individual or group is observed over time 0 Study can require lengthy observation 0 Cross Sectional 0 Individuals or groups of different ages are observed 0 Change is inferred implied not actually observed Cohort o A group whose members share a common characteristic such as age or experience Sequential or mixed longitudinal mini longitudinal studies with overlapping ages 0 Several age groups are observed at one time or over a short time span permitting observation of an age span that is longer than the observation period Chapter Two 01202015 What Was Our System for Understanding Motor Development Newell s model Constraints Type 0 Using a ping pong paddle to play tennis 0 Task 0 Playing poorly because of distractions associated with a recent death in the family 0 Individual functional 0 Riding a bike over mountains terrain in the snow 0 Environmental 0 Riding a unicycle over mountain terrain in the snow 0 Task Theories of Motor Development Maturational perspective 0 Information processing perspective Ecological perspective Maturational Perspective 0 Motor development driven by maturation of systems neural system is important 0 Minimal in uence of environment 0 Characteristics of Motor Development 0 Qualitative o Discontinuous Up and down pattern History of Maturational Perspective 0 1930 s Gesell McGraw Suggested invariable genetically determined sequence of development individuals can have unique timing 0 Research Cotwin control strategy 0 Identical twins Maturationistis Interest in Process McGraw 1935 associated motor behavior changes with development of nervous system Posited that advancement in the central nervous system triggers the appearance of a new skill Long Lasting Beliefs from Maturation Theory 0 Basic motor skills emerge automatically 0 There is no need for special training Mild deprivation does not arrest development The nervous system is most important Descriptive Methodology in Motor Development 0 Characteristics of maturationists o Normative descriptions 0 Practice can skew results 0 Numerical values 0 Use of quantitative scores to describe children s average performance 0 Biomechanical descriptions of movement patters in fundamental skills 0 Halverson gripping How Would a Maturations Explain the Following 0 Toddler learning to walk 0 Basic nervous system function that will develop automatically 0 Timing and motor system development is different 0 Child riding a bike 0 Coordination has or has not developed in order to help a child ride a bike successfully Teenager having difficulty swimming 0 Nervous system development and progression problems 0 Recessive gene Information Processing 0 Also Bandura s social learning 1986 Skinner s behaviorism 1974 0 Basic tenet brain is like a complex computer 0 The passive human responds to stimuli in the environment 0 Research investigates stimulus response links feedback and knowledge of results 0 Young adults often studied rst as basis of comparison for performance of children and older adults Perceptual Motor Development 0 Sub eld exists within the framework of information processing 0 Early work 1960 s tried to link learning disabilities to delayed perceptualmotor development How Would Information Processing Theorist Explain the Following 0 Toddler learning to walk 0 More efficient and quicker way of moving 0 Easier on the wrists and knees than crawling 0 Seeing other people do it 0 Child riding a bike 0 Seeing other people ride a bike 0 Use trial and error as a process to gure it out Teenager having difficulty swimming 0 Someone who has never been around swimming or observed swimming is quite sure what the movements should be 0 Childhood trauma experienced with swimming 0 Not getting the right feedback or processing properly Ecological Perspective Development driven by interrelationship of individual environment and task importance of multiple systems Sound familiar Neural system one of many responsible for action Two branches in the book we cover 3 0 Dynamic systems 0 Perception action 0 MMD Dynamic Systems Theory was advocated in early 1980 s by Kugler Kelso and Turvey among others Body systems spontaneously self organize not driven solely by the CNS Body systems performer s environment and task demands interact Some systems may develop more slowly in the young or degrade faster in the old thus controlling the rate of development or change Development is characterized by qualitative and discontinuous change Change occurs across the lifespan Dynamic Systems Graphing Change Slide look in notebook Dynamical Systems Theory 0 Many systems work together to in uence a human movement task 0 Systems nerves hormones muscles skeleton levers motivation fear gravity oor surface etc o No one system is quotin chargequot 0 An interaction model of these systems 0 Our body the individual the environment and our tasks are constantly changing and interacting o Softly assembled Flexible adaptable Near in nite numbers of possible combinations and resulting movements 0 What combinations of systems do we need to walk Skeletal system Muscular system Safe environment to walk in Coordination a Move in a synchronized pattern a Balance 0 To skip Need more powerful muscle contractions More muscular strength Rhythm change step hop step hop 0 Organization of systems constrains behavior the body s systems do no develop at the same rate 0 Like an assembly line 0 Human system is constantly searching for stability 0 Within that search the system self organizes 0 New movement patterns emerge as the result of interaction between multiple systems 0 Treadmill example walk to run 0 Disturbance within the system Attractor States Perturbation disturbance of motion course arrangement or state 0 Adjusting the speed on the treadmill o Attractor states quotrutsquot where a movement pattern is stable 0 The deeper the well the more attractive the state is o Attractor states can only be reached as a function of all three constraints Control Parameters 0 In uence the characteristics of the behavior 0 Act as an agent for reorganization o Expressed as temp force speed temperature frequency 0 When the behavior loses stability the control parameter is altered and a new behavior emerges o What is the control parameter in the treadmill example 0 Speed and incline Rate Limiters Factor or system that has the most control over development at a given point in time Individual constraint or system that restrains or delays the emergence of a skill What is the rate limiter in the treadmill example 0 Power and speed at which it is set 0 Individual rate limiters Stride length Way an individual pumps their arms for power Stride frequency The body s systems muscular neurological skeletal do not develop at the same thus they sometimes act as restraints o EX ve year old trying to make a basked on a 10 ft goal What is the rate limiter n Muscle strength a Accuracy and precision Development or emergence of a certain skill is only as advanced as the least developed system 0 quotA team is only as good as its weakest playerquot Perception Action Theory is based on the work ofJJ Gibson 1960 s and 1970 s Affordance is the function an environmental object provides to an individual Characteristics de ne objects meanings 0 Object functions are based on individuals intrinsic dimensions ie are body scaled rather than an object s extrinsic objective dimensions 0 Ecological Perspective 0 Both branches reject CNS as executive controller of nearly limitless opportunities for movement 0 Control is distributed throughout the body at both global and local levels Why Do We Need a Metaphor for MD 0 Our ultimate goal in this class is to understand movement 0 What kind of movement l skillful movement 0 What is the ultimate goal of the movement l to be skillful A Few De nitions 0 Fundamental motor skill skill needed to perform a daily task 0 EX walking throwing catching kicking etc 0 Motor skill development start to having no ability in a motor skill to mastering the skill o EX a newborn learning how to walk 0 Motor skill pro ciency being able to perform a movement and repeat is successfully over and over 0 EX free throws in basketball Advantages of the MMD 0 Integrated o Focuses on the developmental product and the process 0 Why is this important 0 Explains not only what behaviors occur in a certain order but also why they occur Prenatal Period 0 A mount s structure begins before the climber arrives at its foot 0 What does that mean 0 The child s parents have their own mountainsgood or bad those mountains contribute to the child s future mountain Smoking radiation excessive caffeine stress OR Excellent nutrition and mental health physically active physically t Re exive Period Re exive re exes Goal facilitate survival and quotopen a dialogue with the environment Goes from roughly the 3rd fetal month to about 2 weeks post birth 0 Divided into two periods prenatal re exive and postnatal re exive 0 Where is the divide for the two periods Birth 0 Prenatal movements are in an effort to prepare for delivery and recovery from birth 0 Two types of movements during the re exive period 0 Spontaneous random kicking ailing mouthing o Re exive motor responses to a speci c stimuli Preadapted Period 0 Goal Achievement of independent function Roughly goes from 2 weeks to 1 year 0 Two basic requirements for independent function 0 The ability to feed oneself and the ability to move through the environment to seek nourishment o Marked by the onset of voluntary movements 0 Reaching grasping etc Fundamental Patterns Period 0 Goal build a sufficiently diverse FMS repertoire that will allow for later learning of adaptive skilled actions that can be exibly tailored to different and speci c movement contexts Context Speci c Period 0 Goal learn how to adaptively apply FMS to a variety of constrained s ua ons 0 Child begins to apply FMS toward a variety of task and environmental contexts o EX child no longer runs for the sake of running but begins to impose different task constraints on how where and why he is running 0 Look at the mountain 0 This stage is shown as multiple and speci c peaks of varying heights 0 Sometimes seen as the quottopquot or end of the mountain Skillful Period 0 Goal achievement of skillful behavior 0 Motor skills are characterized as being voluntary efficient and adavae o If a performer can reach the level of a skill being all three of those things he or she has reached the skillful period 0 One key to this stage performer must be able to apply the behavior to a variety of contexts and situations Skill specialization 0 Rare to see someone reach this period across a wide range of behaviors and contexts Compensation Period Compensate to make up for 0 Change in the constraints that produce a behavior to produce a behavioral reorganization Two types of compensation o Injury induced change in constraints associated with injury 0 Ageassociated changes in constraints associated with aging Ecological Perspective and Overview o If you were an ecological perspective theorist how would you explain the following 0 Toddler learning to walk All systems came together and progressed Got to a point where they all have the ability to do so See their parents and other individuals do it Environment will either encourage or discourage the behavior 0 Child riding a bike Systems coming together at the same time including coordination and balance Environmental factors include where the individual lives a Dirt road a Paved bike paths 0 Teenager having dif culty swimming The individual was not exposed to a swimming environment when they were younger Lack of proper coordination of movements Motivation and fear of water Chapter Three 01272015 De ne Biomechanics 0 Physics of body movement 0 Developmental biomechanics 0 There will be development as systems change in the physics of body movement 0 How values changes as someone develops Changes are Predictable Based on optimizing principles of motion and stability 0 Can be seen across variety of motor skills Often produce more force velocity or accuracy Newton s First Law 0 An object at rest stays at rest and an object in motion stays in motion until acted upon by a force Inertia is resistance to motion related to mass Momentum is the product of mass and velocity Newton s First Law Simpli ed We must exert force to 0 Move objects 0 Move ourselves o More inertia means that o It is harder to move 0 More force application is required Newton s First Law Child Learns to Swing a Bat o What must the child learn about inertia 0 Must apply force to the bat to get it to swing o Exert more force to swing a heavier bat o What must the child learn about momentum 0 Has to be able to stop the bat The larger the bat is the harder it will be to stop Moving an Object Farther or Faster Increase force 0 EX swing the bat harder Increase distance over which force is applied 0 EX Wind up to throw a ball by applying more force on the ball in a forward direction Adding Distance to Improve a Kick 0 Increase step length linear distance 0 Allow you to generate more force to be applied to the ball 0 Increase range of motion rotational distance 0 Can be done by bending both the hip and the knee Also by turning the trunk you can rotate the whole body to generate more force when pivoting about the spine Newton s Second Law Objects force is related to mass and acceleration Fma Object s acceleration is related to applied force and inversely related to mass aFm A person can throw only as hard as he or she can throw 0 Given a constant force level how could you increase acceleration when throwing a ball 0 Decrease the mass Newton s Third Law 0 To every action there is an equal and opposite reaction 0 When you push something it pushes back on you Oppositional Movements Walking 0 Running Skipping Force Generated Aided by Planer Movements Use force in the plane of motion where you want to move yourself or an object 0 Avoid rotational movements that reduce force in the desired plane Increasing Velocity Rotating Limbs and Projected Objects Increase rotational velocity swing it faster 0 Increase relative length fully extend it at release or contact Force and Time 0 To make an object move increase force application for a given time o EX karate chop to brick To make an object stop increase time over which a given force is appHed o EX soft landing in gymnastics Open Kinetic Chain Correctly timed sequence of movements that an individual uses to successfully perform a skill o If timing is off the uidity of the movement is off Question 0 What developmental skills involve learning to absorb forces 0 Boxing o Jumping o Catching strictly absorbing Stability and Balance 0 Stability ability to resist movement 0 Not always a good thing EX if you want to run stability will hinder the ability to run 0 Balance ability to maintain equilibrium 0 Stabilitymobility trade off Increasing Stability Increase base of support 0 Lower the center of gravity Increasing Balance 0 Increase stability 0 Improve strength coordination and proprioception TakeHome Messages 0 The principles of motion and stability apply to all actions and objects 0 Be aware of changing individual constraints o Manipulate task and environment to aid in optimal skill performance 0 Not everyone will become pro cient Using these Principles of Motion and Stability to Detect and Correct Errors 0 Observe the complete skills Analyze each phase and its key elements 0 Use your knowledge of mechanics in your analysis 0 Select errors to be corrected one or more than one 0 Do one at a time 0 Decide on appropriate method for the correction of errors Chapter Four 01292015 Growth and Aging Change Individual Constraints 0 Genetic and extrinsic factors combine to in uence growth and aging We observe patterns in growth and aging o Universality patterns that hold for all humans 0 Speci city individual variation Educators and therapists can make tasks developmentally appropriate Prenatal Development 0 Early development is controlled by genes 0 Normal development 0 Inherited abnormal development 0 The embryo or fetus is sensitive to extrinsic factors 0 Positive effects Prenatal vitamins folic acid need some fat 2030 within the diet avoid stressful situations and maintain some style of exercise levels walking 0 Negative effects Smoking drinking drug use poor diet caffeine consumption etc Embryonic Development Conception to 8 weeks Differentiation of cells to form speci c tissues and organs Limbs formed at 4 weeks 0 Human form noticeable at 8 weeks Fetal Development 0 8 weeks to birth 0 Continued growth by hyperplasia cell number and hypertrophy cell size Cephalocaudal head to toe and proximodistal near to far 0 Plasticity capability of taking on a new function Fetal Nourishment Oxygen and nutrients diffuse between fetal and maternal blood in placenta Poor maternal health status can affect fetus Abnormal Prenatal Development 0 Source of abnormal development can be genetic or extrinsic Congenital defects present at birth can derive from genetic of extrinsic source Genetic Causes of Abnormal Development 0 Can be dominant disorders defective gene from one parent or recessive disorders defective gene from each parent 0 Direct inheritance Can result from mutation of a gene Effects on growth and maturation are variable What are some genetic disabilities 0 Autism down syndrome cystic brosis color blindness and sickle cell anemia What effects does each have on normal growth and development 0 They are all going to effect normal growth and development differently Extrinsic Causes of Abnormal Development Extrinsic factors can affect fetus through nourishment or physical environment Teratogens delivered through nourishment system act as malformationproducing agents Some teratogenic effects result from too much of a substance some from too little Placenta screen some substances ex large viruses but not all harmful ones Harmful environmental factors include pressure temperature X and gamma rays oxygende cient atmospheres pollutants Tissues undergoing rapid development at time of exposure are most vulnerable Assessment of Prenatal Growth Invasive prenatal assessments o Amniocentesis Needle into the amniotic uid 0 Chorionic villus sampling Noninvasive prenatal assessments 0 Ultra sound most common 0 3D images using new imaging software Postnatal Development 0 Overall growth follows sigmoid Sshaped pattern 0 Timing of spurts and steady periods can vary between individuals 0 Timing differs between the sexes 0 Especially with height and weight Assessment of Extent and Rate of Postnatal Growth 0 Distance curves show extent of growth 0 Velocity curves show rate of growth 0 Peaks on velocity curves show ages at which rate of growth changes from faster to slower 0 Peaks growth spurt Height 0 Follow sigmoid pattern 0 Girls 0 Peak height velocity occurs at 115 to 12 years 0 Growth in height tapers off around 14 ends around 16 0 Boys 0 Peak height velocity occurs at 135 to 14 years 0 Growth in height tapers off around 17 ends around 18 0 Long growth period of males contributes to absolute height differences Growth in Length and Stature 0 Mid growth spurt in height 0 Between 65 and 85 years 0 More common in girls 0 Girls enter adolescent growth spurt 2 years before boys Predicting adult stature o Stature 2x child s height in inches at 2 years of age 0 If child at 2 years of age 36 inches as an adult he will be 72 inchestaH Individual Variation 0 Average ages for peak height velocity and tapering of growth are based on groups 0 Individuals can differ from the averages o In what ways can individuals vary from the average pattern 0 Having a really early or late growth spurt Don t measure maturation o Averages don t take maturation into effect Weight Follows sigmoid pattern ls susceptible to extrinsic factors especially diet and exercise Individuals grow up then ll out peak weight velocity follows peak height velocity by 255 months in boys 35105 in girls BMI for Age In children and adolescents BMI for age is best used as a guide to determine individual nutritional status BMI for age between the 85th and 95th percentile is classi ed as risk for becoming over weight BMI for age greater than the 95th percentile means overweight is a concern Relative Growth Body as a whole follows sigmoid pattern speci c parts tissues and organs have different growth rates Body proportions change from headheavy shortlegged form at birth to adult proportions ln adolescence boys increase in shoulder breadth Body Proportions Are adults all of the same proportions o No Described differences in proportion among your friends and acquaintances o Torso length 0 Leg length 0 Hip width linear pattern Physiological Maturation As children and youth become older they grow in size and mature 0 Children vary in maturation rate o It is difficult to infer maturity from age alone size alone or age and size together Implications of Maturation Rate 0 How should we counsel parents of an early mature and star athlete about the child s future in athletics o Other children will start to catch up in a few years Won t always be the biggest fastest or stronger kid 0 Develop good fundamentals in an all around game Good no matter what the size is 0 Have a child play up an age group Secondary Sex Characteristics 0 Characteristics appear as a function of maturation They appear at a younger age in early maturers Have you seen variations among a group of preteens in appearance of secondary sex characteristics Which ones 0 Males facial hair 0 Females breast tissue Extrinsic In uences on Postnatal Growth 0 Individuals are especially sensitive during periods of rapid growth 0 Catchup growth demonstrates extrinsic in uences o What extrinsic factors are most likely to affect growth during infancy During the adolescent growth spurt 0 Nutrition infant 0 Exercise and diet adolescence Adulthood and Aging 0 Height is stable in adulthood but may decrease in older adulthood 0 Compression of cartilage pads o Osteoporosis 0 Average adult starts gaining weight in the 205 0 Diet and exercise 0 Loss of muscle mass Physique Overall body form WH Sheldon 1940 rated physique by three components 0 Endomorphic round 0 Mesomorphic muscle 0 Ectomorphic thin Body Proportion and Motor Performance 0 Balance is superior in women and girl due to shorter legs and wider pelvis 0 Lower center of gravity 0 Wide hips short legs and a low center of gravity make running and jumping tasks dif cult for girls Wider shoulder and longer arms in boys and men is an advantage for throwing events Chronological Age and Physical Maturation How do we measure it 0 Height age 0 Sex maturity o Skeletal maturity Dental Maturity and Menarche 0 Dental Maturity 0 Dental age assessment Count the number of teeth that have emerged Radiographs can be used Menarche o The onset of menstruation 0 Mean age in developed countries is 132 years Often occurs earlier in American girls 0 Signi es uterine maturity not reproductive maturity Age of Menarche To determine the age of menarche ask questions 0 Do you know what menstruation means Have you already menstruated Can you remember the exact date of your rst menstruation What grade were you in Was the event close to your birthday 0000 Growth Maturation and Aging Summary Prenatal development is in uenced by genetic and extrinsic factors Most extrinsic factors are in uential through the nourishment system Growth abnormalities can be caused by genes environment or both Whole body growth follows sigmoid patterns with timing differences between the sexes and between individuals With advancing age extrinsic factors contribute more to individual vadathy Maturation and Motor Performance The level of maturation can affect motor performance Post pubescent boys initially outperform pre pubescent boys Once the late maturing boys reach adolescence the advantage is not longer evident Early maturation is not associated with superior motor performance in girls except in swimming Late maturing girls have superior motor performance Chapter Five 02052015 Body Systems Individual Structural Constraints 0 Body systems are in uenced by extrinsic factors o It is important to know 0 The average pattern of change within each system 0 The range of individual variations for a system Rate Limiting Constraints 0 A system that lags in development can be a developmental rate limiter Give an example of a system acting as a developmental rate limiter o Skeletal muscle adipose neurological and endocrine Skeletal System 0 The embryo has a cartilage model of the skeleton Ossi cation begins at primary centers in the mid portions of long bones Postnatal Growth in the Skeletal System 0 Growth in bone length occurs at secondary centers at the ends of bones These centers are called epiphyseal plates growth plates or pressure epiphyses Increase in bone girth is called appositional growth Traction epiphyses are where muscle tendons attach to bones Assessment of Skeletal Age lndividual s hand wrist Xray is compared with standards for average skeletal development by chronological age lndividual s xray is matched with picture for ossi cation at ends of long bones and in short round bones Cessation of Bone Growth 0 Growth at epiphyseal plates stops at different times for different bones All typically close by age 18 or 19 0 Closure occurs at a younger age in girls What does this re ect about the connection between skeletal growth and maturation 0 Keep adding weight 0 Neurological system is still developing up until the age of about25 Skeletal System in Adults 0 Bone undergoes remodeling through the lifespan Old bone is absorbed new bone is formed In adulthood bone growth slows fails to keep face with reabsorption Bone becomes more brittle Skeletal Structure in Adulthood Structure itself changes little unless one has osteoporosis Osteoporosis leads to rib cage collapse stooped posture and reduced height Extent of bone loss is in uences by hormone levels diet and exercise 0 Estrogen levels 0 Post menopausal women get hormone therapy Muscular System Prenatal growth involves hyperplasia and hypertrophy Postnatal growth mainly involves hypertrophy Muscle growth follows sigmoid pattern Muscles increase in diameter and length by addition of sarcomeres Differences between the sexes become marked in adolescence especially in upper body musculature Muscle Fiber Type Adult muscle is composted of type 1 type 2a type 2b bers At birth 15 to 20 of bers are undifferentiated By age 1 distribution of muscle ber type is similar to adult distributions Exact proportions vary between individuals Muscular System in Adults Loss of muscle mass is minimal until age 50 o Sarcopenia By 80 average 30 of muscle mass is lost Loss occurs in number and size of muscle bers the latter usually after age 70 Whether type 2 bers undergo greater loss is unclear Cardiac Muscle Prenatally the heart grows by hyperplasia and hypertrophy Postnatal heart follows a sigmoid pattern Heart and blood vessel size is appropriate for body size in childhood and adolescence ln old age heart can lose elasticity and valves can become more brotic depending partly on lifestyle Adipose System Some fat is needed for energy storage insulation and protection Fat increases rapidly until age 6 months then gradually until age 8 years In adolescence girls increase fat more dramatically than boys do Growth is by hyperplasia and hypertrophy the latter more dramatic in adolescence Individual variability is great Fat Distribution Body fat distribution changes with growth Children have more internal than subcutaneous fat Subcutaneous fat increases from age 6 to 7 years until age 12 or 13 in boys and girls Subcutaneous fat then continues to increase in girls Adipose Tissue in Older Adults 0 Both men and women tend to gain fat during adulthood but this is not inevitable Increases in trunk fat are notable but subcutaneous fat on limbs tends to decrease Implications Give examples of excess adipose tissue serving as a rate limiting system 0 Not being able to perform certain exercise movements 0 Decrease mobility 0 Everyday activities such as picking things up off the growth 0 Air travel seating etc Endocrine System 0 Plays role in regulating growth and maturation through chemical substances called hormones Excess of de ciency can alter growth 0 Major hormones involved in growth include o Pituitary growth hormone o Thyroid hormones 0 Two gonadal hormones These hormones stimulate protein anabolism tissue building Endocrine neurological feedback loops regulate hormone levels 0 Each hormone may have a critical role in development at speci c phases in life span Insulin plays indirect role is vital for carbohydrate metabolism Growth Hormone Growth hormone is secreted by the anterior pituitary It is necessary for normal growth De ciency can result in growth abnormality Thyroid Hormones These are secreted by thyroid gland 0 They in uence whole body growth 0 One plays a role in skeletal growth Gonadal Hormones In uence on growth sexual maturation sex organs secondary sex characteristics Androgens o Secreted by testes boys adrenal glands boys and girls 0 Hasten epiphyseal growth plate closure 0 Promote growth of muscle mass Estrogen o Secreted by ovaries girls adrenal cortex girls boys 0 Hastens epiphyseal growth plate closure 0 Promotes accumulation of fat Endocrine System in Older Adults lmbalances may develop between nervous endocrine and immune systems Thyroid disorders are more prevalent Decreasing gonadal hormone levels are associated with loss of bone and muscle tissue Nervous System Genes direct its development Extrinsic factors exert in uence especially in the formation of synaptic connections Prenatal Neural Development Process generally includes neuron formation differentiation into general type and migration Once in place neurons develop an axon to carry signals to neurons glands organs muscles Teratogens might disturb normal migration and branching o Affects this system the most Late in prenatal period neurons start to re electrical impulses 0 Experience might play role in synaptic proliferation strengthening some connections weakening others 0 Neural network becomes more efficient with experience Postnatal Neurological Growth 0 Brain growth increases rapidly after birth 0 Growth involves these factors 0 Increases in size of neurons 0 Proli c branching to form synapses o Increases in glial cells for support and nourishment of neurons 0 Increases in myeIin to insulate axons Stimulation of learning increases number of synaptic connections Brain Structures Spinal cord and lower brain centers are relatively advanced at birth Cerebral cortex gradually becomes more functional after birth Myelination of axons allows faster conduction of neural impulses o Direction of myeIination tends to follow direction of conduction Nervous System in Older Adults 0 Loss of neurons dendrites synapses neurotransmitters and myeIin One theory of aging suggests that breaks in neural network links cause detours and therefore slowing 0 Exercise promotes improved cognitive function Implication What can older adults do to keep their brain functioning well 0 O O O Puzzles Crosswords Reading Card games Learning something new Model of Constraints 0 Which body systems interact with others How and for what funcUon o All of the systems balance off one another to maintain proper 0 body movement and function Endocrine system and circulatory systems help to transport hormones throughout the body Development and Aging of Body Systems Summary 0 Systems interact as they develop and age 0 During periods of rapid change a system might be more sensitive to extrinsic factors Extrinsic factors play a greater role genetic factors lesser role as one moves through life 0 Model of constraints shows that a system can act as a rate limiter during growth or as accelerator of aging Chapter Six 02102015 Early Motor Behavior Re exive or spontaneous o Re exive movements stereotypical responses elicited by speci c external stimuli o Spontaneous movements stereotypies movements not caused by known external stimuli Spontaneous Behaviors Original theory extraneous no purpose 0 Current theory building blocks similar to some voluntary movements 0 Examples 0 Spontaneous arm movements resemble reaching 0 Spontaneous kicking resembles adult walking Re exes Re exive movements occur quickly after onset of stimuli They involve single muscle or speci c group of muscles not whole body 0 They cannot be extinguished at any one time Persistence may indicate neurological problems Purposes of Re exes o Built in responses facilitate survival Re exes allow dialogue with environment Re exive movements result in sensory consequences adaptation Re exes provide building blocks for future movement Role of Re exes in Survival Primitive re exes 0 Protection 0 Nutrition 0 Survival 0 Appear during gestation or at birth 0 Disappear by 6 months of age Postural re exes 0 Basis for future movements 0 Stimulation from higher brain centers Asymmetrical Tonic Neck Re ex 0 Infants starts in supine position Stimulus turn head to one side 0 Response same side arm and leg extend Grasp and STNR Palmar Grasp Re ex o Stimulus touch palm with nger or object 0 Response hand closes tightly around nger or object Symmetrical Tonic Neck Re ex 0 Infants starts in supported sitting position 0 Stimulus extend head and neck or ex head and neck 0 Response Arms extend and legs ex and arms extend Moro Re ex 0 Infant starts in supine position Stimulus shake head 0 Response Arms legs and ngers extend then arm and legs ex Stepping Re ex Stimulus Place soles of feet on a at surface 0 Response Legs move in a walking position Constraints 0 What constraints exist during the re exive period 0 Structural Nervous system 0 Functional Balance and strength 0 Environmental physical 0 Environmental sociocultural 0 Task goals rules equipment lnfantile Re exes Chart 0 Know re exes 0 Know the stimulus Know what happens response Later lnfancy 0 Voluntary control of movements 0 Understanding of environment objects in environment 0 Meaningful interactions with others Postural reactions Postural Reactions 0 Begin around 4 months 0 Help maintain posture in changing environment 0 Initially similar to re exes then incorporated into general repertoire Labyrinthine Righting Re ex Infant is supported upright Stimulus tilt infant Response head moves to stay upright More Postural Reactions Derotative Righting 0 Infants starts in supine position 0 Stimulus turn head to one side or turn legs and pelvis to other side 0 SLIDES Motor Milestones Fundamental motor skills 0 Building blocks leading to complex motor skills 0 Cumulative sequential Speci c movements that lead to general actions Loco motor and Posture Motor Milestones o 2 months lifts head in prone position 0 3 months lifts should turns head 5 months rolls over sits unsupported 7 months gets on hands and knees 8 months creeps on hands and knees 9 months pulls to stand cruises furniture 0 10 months stands alone 0 12 months walks aone Rate Limiters or Controllers 0 Individual constraints that inhibit or slow attainment of a motor skill o Rapidly changing during early childhood 0 What important rate limiters during infancy may control development of the following o Crawling Strength Neurological system 0 Reaching Strength Neurological system 0 Walking Balance Strength Coordination Development of Postural Control and Balance in Infancy Rate limiters for posture and balance appear to involve coupling sensory information and motor response Infants continuously calibrate sensory motor response Researchers Have Cited Three Views on the Role of Re exes The structural explanation re exes re ect the structure of the nervous system The functional explanation re exes help an infant to survive The applied explanation re exes lead up to voluntary skills giving infants an opportunity to practice coordinated movements before they are voluntary Looking Back The perspective that re exes are not related to later voluntary movement is consistent with maturational theory As the cerebral cortex and spinal motor pathways mature the cortex takes control over lower brain and spinal cord centers The perspective that re exes are related to later movements is consistent with the dynamic systems theory Re exive movements can be elicited or dampened by manipulating task and environmental constraints Individual Constraints Maturation of the central nervous system the only individual constraint emphasized by maturationists Development of muscular strength and endurance Development of posture and balance Improvement of sensory processing
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