Test 1 Flashcards
(90 cards)
1
Q
What is the main point of this course?
A
Constraints-based approach to understanding the development and regression of motor skills across the
lifespan
2
Q
What is the point of studying motor control?
A
Motor Control
– Understanding how the nervous system controls muscles to permit skilled and coordinated movements
3
Q
What is the definition of coordination?
What is the problem with understanding coordination?
A
Coordination involves bringing body
parts into a functional relationship in
order to achieve a task goal
* The problem of understanding
coordination is that redundant
biomechanical degrees of freedom
create an infinite number of possible
movements
4
Q
What is the difference between motor control and motor learning?
A
- Motor Control
– Understanding how the nervous system controls muscles to permit skilled and coordinated movements - Motor Learning
– Changes in skilled and coordinated movements that are related to experience and practice
5
Q
What kind of process is motor development?
What is the definition of functional capacity and what kind of process is it?
A
- Development is a continuous process of change in functional capacity
– Functional capacity is the ability to successfully interact with the world
Represents a cumulative process
– development is always occurring, but the amount of change may be more or less noticeable at various points in the lifespan
6
Q
How is motor development related to age?
What kind of change is involved in motor development?
How does motor development occur?
A
- Development is related to, but not dependent on age
- Development involves sequential change
- Development occurs through maturation and growth of all body systems AND its interactions with environment and task
7
Q
What is the difference between physical growth and physical maturation?
What is the definition of aging?
A
- Physical growth: quantitative
increase in size or body mass (Timiras,
1972) - Physical maturation: qualitative
advance in biological makeup (Teeple,
1978) - Aging: process occurring with
passage of time, leading to loss of
adaptability or full function and
eventually to death (Spirduso, 1995)
8
Q
How does motor progress change through life?
A
Looks like a bell curve
(participant throws a ball slow as a child, throws it fast as a young adult and throws it slow again as an older adult)
9
Q
What is the difference between universality and versatility?
A
Universality vs Variability
– Individuals show a great deal of similarity in the course of development
* Common developmental stages based on shared characteristics
* Typical or average behaviours can be useful for tracking developmental change
* BUT, variations from the average
* Individuals can also skip ‘milestones’ (i.e., follow different pathways in development).
10
Q
What is the debate between nature and nurture?
A
- Nature vs Nurture
– Contributions of genetics and environmental factors - Nature = genetics
- Nurture = environment
11
Q
How does walking progress through the first year of life?
A
starting at 2 months-prone, chest up, use arms for support, roll over
starting at 3 months-support some weight with legs
starting at 5 months-sitting and standing without support
starting at 6 months-pull self to stand
starting at 7 months-stand using furniture for support
starting at 10 months-standing alone easily
starting at 11 months-walk alone easily
12
Q
What is an example of evidence for both the nature and nurture argument?
A
nature-young child who was a musical prodigy
nurture-10,000 hours of deliberate practice rule
13
Q
What are 2 things that motor development affects?
Are the terms growth, maturation and aging synonymous?
A
- Development is an ongoing process that occurs throughout the lifespan
– Motor Development affects motor control - Bernstein’s degree of freedom problem
– Motor Development affects motor learning
– No, the terms growth, maturation, and aging each have their own meaning
14
Q
What is the difference between longitudinal and cross-sectional research?
A
Longitudinal research
– Same individuals are observed over a long period of time (e.g., at 5, 10, 15 and 20 years old)
Cross-sectional research
– Different individuals of various ages are observed at the same point in time (e.g., in 2010 groups of children born in 1990, 1995, 2000, 2005 are observed)
15
Q
What is a cohort?
What is the cohort effect?
A
- Cohort: a group whose members share a common characteristic, such as age or experience
- Cohort Effect: motor differences that can be explained by a common characteristic other than developmental change
16
Q
How have researchers attempted to
classify and explain patterns of
developmental change?
(6 theories)
A
– Maturation of the CNS
– Normative Descriptive
– Biomechanical Descriptive
– Information Processing
– Dynamic Systems
– Perception/Action
17
Q
Who was the maturational perspective strongly influenced by?
What did it primarily focus on?
What did Gesell believe about individual variation?
A
- Strongly influenced by the works of
Gesell and McGraw. - Focused primarily on the individual – biological and genetic factors
- Gesell – individual variation has more to do with genetic heritage than environment
18
Q
What body system did proponents of the maturational perspective think was primary attributed to?
How did they believe growth and maturation occurred?
A
- Motor development is primarily attributed to growth and maturation of the central nervous system (CNS)
– Other body systems are relatively unimportant
– Growth and maturation of the CNS triggers the emergence of new skills
19
Q
What experiment did Myrtle Mcgraw complete and what were the results?
A
- Co-twin experiment
- Results – Dependent on type of
motor skills - Researchers have challenged
results
20
Q
The ecological perspective believed that the interrelationship of 3 variables drove development; what are they?
What are the 2 major branches of the ecological perspective?
A
Individual
Environment
Task
- Two major branches
1. Dynamic systems
2. Perception–action
21
Q
Who was the dynamics systems theory proposed by?
How was the concept of constraints relevant to their theory?
A
- Theory was advocated in early 1980s by
Kugler, Kelso, and Turvey (among others) - Body systems spontaneously self-organize (not driven by thought process of CNS)
– Organization is driven by constraints
– Constraints are channels by which movement can occur; they both encourage and discourage certain
movement patterns
22
Q
What is the normative descriptive period?
Which development perspective was this period influenced by?
A
A movement concerned with standardized tests and norms that would describe children’s average performance in terms of quantitative measures on motor performance tests
(ex. they described the average running speed/jumping distance/throwing distance of children at specific times)
They were influenced by the maturational perspective but
they focused on the products
(scores,outcomes) of development rather that on the developmental processes that lead to these outcomes
23
Q
What is the biomechanical descriptive period?
A
They made careful biomechanical descriptions of the movement patterns that children used for fundamental tasks and were able to identify the course of sequential improvement that children followed in attaining biomechanically efficient movement patterns.
24
Q
What is the information processing perspective?
A
Focused on environmental or behavioral causes of development, they believed the brain acts like a computer that takes in information as an input to later process it and output a movement.
This perspective emphasized the formation of stimulus-response bonds, feedback and knowledge of results.
25
What was the progression in motor learning perspectives between information processing, biomechanically normative and normative?
Normative was first
Moved on to biomechanically normative after normative
Information processing is the newest perspective
26
What is the dominant perspective used by motor researchers?
What is involved in this perspective?
What is different between this perspective and the maturation perspective?
Ecological perspective is the most common perspective used now
Focuses on the interrelationship between the individual, the environment and the task and all constraints must be considered in order to understand the emergence of a motor skill
(ex. body type, motivation, temperature, ball size)
The ecological perspective considers motor development to be caused by the development of multiple systems whereas the maturational perspective only considers one system(the CNS)
27
What are the 3 stages of prenatal development?
Germinal
Embryonic
Fetal
28
What are the characteristics of each month of development, from 1-9?
Month 1:
-Vertebral column forms; heart forms; small buds for arms and legs form; other body systems begin
Month 2:
Eyes and nose forms; limbs become longer; fingers and toes begin to form; ossification begins at end of the month
Month 3:
Eyes and nose further develop; ears begin to form; ossification continues
Month 4:
Hair begins to appear on head; continued development of body systems; joints begin to form
Month 5:
Head becomes less disproportionate; lanugo develops; rapid development of body systems continues
Month 6:
Eyelids separate, eyelashes form; nails growing; vernix covers skin
Month 7:
Most body systems fully developed; premature birth possible(age of viability)
Months 8/9:
Subcutaneous fat is shedded; lanugo is shed
29
What are 6 ideal factors for a fetus?
1.Absence of abnormal genes
2.Adequate supply of oxygen
3.Adequate supply of nutrients
(vitamins/minerals)
4.Absence of disease
5.Absence of chemical substances
6.Absence of maternal stress
30
What body system is most important in the maturation perspective?
What are the 2 branches of ecological perspective?
– Maturation perspective
* CNS
– Ecological perspective
* Dynamic systems + Perception-action
31
What is the major theory behind the dynamic systems perspective?
How do body systems develop according to the dynamic systems perspective?
* Body systems spontaneously self-organize
(not driven by thought process of CNS)
– Organization is driven by constraints
– Constraints are channels by which
movement can occur; they both
encourage and discourage certain
movement patterns
* Body systems develop at different rates.
– Movement only emerges when all systems are at necessary point of development
– Slowest system is called the rate limiting system
32
Who is the leader behind the perception-action perspective?
What is an affordance in this theory?
How does this effect motor development?
* Based on the work of J.J. Gibson (1960s and 1970s)
– Direct perception
* An affordance is the function an environmental object/terrain provides to an individual (as perceived within their individual constraints)
* The characteristics of an object/setting define its meaning to the individual and how they can act with(in) it
– Graspability, catchability, climbability,
“snowboardability”
33
How do objects function according to the perception-action perspective?
Object functions are perceived based on the individuals’ dimensions (i.e., are body scaled) rather than the object’s actual properties
34
What are the 3 types of constraints according to newell's model of constraints?
1. Individual constraints
(structural/functional)
2. Task constraints
3. Environmental constraints
35
What is the definition of a structural constraint and what are 2 examples of structural constraints?
How do these change with time?
(subtype of individual constraint)
Structural Constraints
* Related to the body’s physical structure
– ex. hinge structure of the
elbow constrains movement to one plane
– Ex. Cardiorespiratory system development
* Structural constraints may change with growth and aging
36
What is the definition of a functional constraint and what are 4 examples of functional constraints?
How do these vary between individuals?
(subtype of individual constraint)
Functional Constraints
* Related to behavioural function.
Examples are
– motivation, attention, previous experience, knowledge
* Functional constraints may vary widely between individuals
37
Are environmental constraints task-specific?
What is the definition of an environmental constraint?
What are 3 examples of environmental constraints?
How do these affect our performance?
What is another type of environment besides the physical environment?
* External to the individual and global rather than task-specific
* Properties of the world around us
– Examples: Gravity, floor surface/ terrain, weather conditions
– Affect how an individual is able
to perform (interact with structural and functional constraints of the individual)
* Sociocultural environment
– Cultural and societal values/conditions
– Affects opportunities and experiences
38
What are two examples of task constraints?
In baggo, you assume that you have to throw the bean bag underhand to be more accurate
In the "crash the can" game, you assume you throw the bean bag overhand to hit the most cans down
39
What kind of landscape does the interaction of the 3 constraints create?
* Interaction of individual, environmental and task-related constraints
* Creates an “attractor landscape” in which certain behaviour is more
or less likely to occur
40
How does the leboyer technique of birthing relate to traditional hospital birthing?
Alternative birthing styles
– Leboyer technique
* Dim room, no noises, warm bath for baby, placement of baby with Mom asap, massage to incite first breath
– Traditional hospital
* Bright lights, loud, cold air, test baby first, smack on the butt to induce first breath
41
How was the gentle birth hypothesis tested?
* Nelson, et al (1980)
– 28 women traditional hospital
– 28 women Leboyer technique
– Measures:
* Amount of crying at birth
* Assessment tests at
– 24 hours
– 72 hours
– 8 months
42
It takes only 9 weeks after conception for the developing fetus to resemble a human.
T or F?
True
43
Premature births are typically due to poor prenatal care.
T or F?
False
44
The respiratory system is the last to develop.
T or F?
False
45
Boys are more affected than girls with x-linked recessive disorders.
T or F?
True
46
The mother’s placenta serves to protect the fetus from harmful viruses/drugs while in the womb.
T or F?
True
47
The primary cause of spina bifida is a family history of neural tube defects.
T or F?
False
48
How long does conception to birth take?
What are the 3 stages of this process?
38 weeks
1. Germinal
2. Embryonic
3. Fetal
49
How long is the germinal stage?
When does it begin?
How hard is this process?
Where does the zygote travel and what does it transform into?
Germinal Stage (0-14 days)
* Begins at sperm penetration into ovum (zygote).
* Fertilization process is not as easy as one would think!
Zygote travels down fallopian tube and develops into a blastocyst
50
How long is the embryonic stage?
When does this stage start?
How important is this stage?
Embryonic Development (2 – 9 weeks)
* Starts once blastocyst attaches to uterine wall and gastrulation begins.
Most Critical Period
51
What is the term for the development of the major organ systems?
The term for the development of the major organ systems is "organogenesis." Organogenesis refers to the process during embryonic development in which the various organ systems of the body begin to form from the embryonic tissues.
52
What function does the amniotic fluid within the amniotic cavity serve?
The amniotic fluid within the amniotic cavity serves several important functions during pregnancy:
Protection: It acts as a cushion, providing a protective barrier to the developing fetus, preventing physical trauma from external forces.
Temperature Regulation: Amniotic fluid helps regulate the temperature around the fetus, maintaining a stable and warm environment.
Buoyancy: It allows the fetus to move and exercise its developing muscles without the constraints of gravity.
Nutrient Transport: Amniotic fluid contains essential nutrients that can be absorbed by the fetus through swallowing and respiration.
Lung Development: Fetal lungs may secrete and absorb amniotic fluid, which is essential for proper lung development. It helps the lungs grow and expand, practicing for breathing after birth.
Infection Barrier: It serves as a barrier to protect the fetus from infections and harmful substances, as it acts as a physical and immunological barrier, preventing some microorganisms and toxins from reaching the fetus.
53
How long is the fetal stage?
What starts to appear at the beginning of the fetal stage?
What are 2 important characteristics of this stage?
Fetal Development (9 weeks – birth)
* Appearance of bone cells marks beginning of fetal stage
1.At this point, fetus resembles a human
2.Continued growth by hyperplasia (cell number) and hypertrophy (cell size)
54
What are the 2 main principles of growth?
Proximo-distal growth
– Direction of growth proceeds from the core of the body out toward the extremities
Cephalo-caudal growth
– Direction of growth proceeds from the head and extends towards the lower bod
55
Make a list of 5 examples of both proximo-distal growth and cephalo-caudal growth?
Proximal-Distal Growth:
1.Growth of fingers and toes (from the center of the hand or foot outward).
2.Development of the upper arm (proximal) before the forearm (distal).
3.Formation of the hip joint (proximal) before the lower leg (distal).
4.Growth of hair on the scalp (starting near the scalp and extending outward).
5.Elongation of the spinal column (from the neck or upper back downward).
Cephalo-Caudal Growth:
1.Growth of the brain and head (cephalic region) before the rest of the body.
2.Development of facial features (eyes, nose, mouth) before the torso and limbs.
3.Formation of the spinal cord and vertebrae in a head-to-tail sequence.
4.Growth of the arms and legs, starting from the shoulders and hips and extending toward the hands and feet.
5.Progression of motor skills, such as crawling and walking, from the head down to the lower body.
56
What are 4 functions of the vernix?
* moisturizing the infant's skin
* facilitating passage through the
birth canal
* conserve heat and protect the
delicate newborn skin from environmental stress
* antibacterial effect
57
What body system needs to be ready for a viable birth?
For a viable birth, the following body systems in the developing fetus need to be sufficiently developed and functional:
Respiratory System: The lungs of the fetus must be sufficiently developed to allow the baby to breathe independently upon birth. This includes the development of surfactant, a substance that prevents the lung's air sacs from collapsing.
Cardiovascular System: The fetal heart should be able to pump blood effectively, delivering oxygen and nutrients to the body's tissues and removing waste products. The circulatory system should be able to handle the transition from receiving oxygen through the umbilical cord to obtaining it through breathing.
Central Nervous System: The brain and spinal cord should be adequately developed to regulate essential functions such as breathing, heart rate, and body temperature. The baby's nervous system should be capable of responding to stimuli and controlling basic reflexes.
Digestive System: While the digestive system is not immediately required for survival at birth, it should be developed enough to allow the baby to begin digesting milk or formula shortly after delivery.
Renal System: The kidneys should be functional enough to filter waste products and regulate fluid balance, maintaining proper electrolyte levels in the body.
Immune System: While not fully developed at birth, the baby should have some immune system function to provide initial protection against infections. Further development of the immune system occurs after birth.
Musculoskeletal System: The baby's muscles and bones should be developed enough to allow for movement and basic reflexes.
Thermoregulatory System: The baby should have some ability to regulate body temperature to stay warm outside the womb.
Integumentary System: The skin should be fully formed and provide a protective barrier against pathogens and dehydration.
The readiness of these body systems is essential for the newborn's ability to survive and adapt to the extrauterine environment. The exact degree of development required for viability may vary depending on gestational age and individual health factors. Premature infants may require specialized medical care and support to ensure their survival and development.
58
What are some major causes of premature birth?
Premature birth, also known as preterm birth, occurs when a baby is born before 37 weeks of pregnancy have been completed. The exact causes of premature birth can be complex and often involve a combination of factors. Some common causes and risk factors include:
Multiple Pregnancies: Carrying twins, triplets, or more can increase the likelihood of premature birth, as the uterus may stretch more than with a single fetus.
Infections: Infections of the genital or urinary tract, as well as systemic infections, can lead to preterm labor.
Chronic Health Conditions: Conditions such as diabetes, high blood pressure (hypertension), and certain autoimmune disorders can increase the risk of premature birth if not well-managed.
Cervical Insufficiency: A weak or prematurely dilating cervix can result in preterm birth.
Placental Problems: Complications with the placenta, such as placental abruption (detachment) or placenta previa (low-lying placenta), can lead to premature birth.
Uterine Issues: Abnormalities in the structure or function of the uterus can contribute to preterm labor.
History of Preterm Birth: Women who have previously had a preterm birth are at higher risk for subsequent preterm births.
Short Time Between Pregnancies: Getting pregnant again shortly after a previous pregnancy may increase the risk of preterm birth.
Smoking and Substance Abuse: Smoking, drug use, and excessive alcohol consumption during pregnancy can increase the risk of preterm birth.
Inadequate Prenatal Care: A lack of access to or engagement with prenatal healthcare can result in missed opportunities to identify and manage risk factors.
Stress and Psychological Factors: Chronic stress, anxiety, and depression during pregnancy have been associated with an increased risk of premature birth.
Teenage Pregnancy and Advanced Maternal Age: Both very young and older mothers (over 35) have a slightly higher risk of preterm birth.
Fetal Growth Restriction: If the fetus is not growing adequately in the womb (fetal growth restriction), it may be at risk for preterm birth.
Certain Pregnancy Complications: Conditions like gestational diabetes and preeclampsia can sometimes lead to preterm birth if not managed effectively.
Environmental Factors: Exposure to environmental toxins and pollutants may contribute to an increased risk of preterm birth.
59
What are some drawbacks of premature birth?
* Lack of adipose tissue development
* Needs for temperature-controlled
environment
60
How many months of development are required for pre-mature birth to be viable?
7 months
61
can you generate three factors that
you think contribute to normal
prenatal development?
Nutrition: Adequate and balanced nutrition is crucial for the developing fetus. A mother's diet during pregnancy provides essential nutrients such as folic acid, iron, calcium, and protein, which are vital for fetal growth and development. Proper nutrition supports the formation of the baby's organs, bones, and tissues and helps prevent developmental issues.
Prenatal Care: Receiving regular prenatal medical care is essential for monitoring the health of both the mother and the developing fetus. Prenatal healthcare includes regular check-ups, screenings, and ultrasounds to ensure that the pregnancy progresses normally and that any potential issues are detected and addressed promptly.
Maternal Health and Lifestyle: The overall health and lifestyle choices of the expectant mother significantly impact prenatal development. Avoiding smoking, alcohol, and recreational drugs, managing chronic health conditions, and minimizing stress are crucial factors in promoting a healthy pregnancy. A mother's well-being directly affects the well-being of the developing baby.
These factors, along with genetics and other environmental influences, play a critical role in supporting normal prenatal development and ensuring a healthy start for the baby.
62
What are 6 ideal factors for a fetus?
* Absence of abnormal genes
* Absence of disease
* Absence of chemical substances
* Absence of maternal stress
* Adequate supply of oxygen
* Adequate supply of nutrients
(vitamins and minerals)
63
What are 4 things that genetic disorders can result from?
Genetic disorders can result from
1. Dominant gene inheritance
2. Recessive gene inheritance
3. Sex-linked recessive gene inheritance
4. Gene mutation (e.g., Down syndrome)
64
What is the definition of a dominant disorder?
What is polydactyly?
What kind of disorder is huntington's chorea?
Mutation on one of the 22 autosomal chromosomes inherited is sufficient to
cause disorder.
* ex. Polydactyly; having 6 or more digits
* Movement disorder
– Huntington’s chorea
65
What is the definition of a recessive disorder?
What is cystic fibrosis?
* Inheritance of mutation on two autosomal chomosomes needed to express gene
* ex. Cystic fibrosis
66
What is the definition of a sex-linked recessive disorder?
Which gender is more affected?
What are 3 common examples?
* X sex chromosome carries the
disorder
* Men tend to be affected whereas
women are typically carriers
* Common examples
– Color blindness
– Hemophilia
– Duchenne muscular dystrophy
67
What are 2 ways that extrinsic factors can affect the fetus?
What are 3 examples from the physical environment?
Extrinsic factors can affect fetus through physical environment or nourishment
– Physical environment
* Internal/external pressure
* Temperature
* Exposure to x-rays or gamma rays
68
How is nourishment an external factor for fetal development?
* Oxygen and nutrients diffuse between fetal and maternal blood in placenta to contribute to growth and maturation of the fetus.
– Competition for resources.
– Importance of maternal health status
69
How are teratogens delivered to the fetus?
What are 4 ways that teratogens cause deviation from normal development?
What are the 3 different categories of teratogens?
* Teratogens can be delivered through the nourishment system.
* Teratogens produce a consistent deviation from normal development, which can include: (1) malformation,
(2) growth retardation, (3) functional defect, and even (4) death.
* Teratogens can be characterized in three different categories: Deficiency, excess, and mere presence
70
What is the definition of a deficiency teratogen and what are 3 examples?
Not getting enough of something that should be in the system;
Examples: general nutritional deficiency, folic acid, Vitamin D
71
What is the definition of an excess teratogen and what is an example?
Getting too much of something that should be in the system
Examples: Too much Vitamin A
72
What is the definition of a mere presence teratogen and what are 2 examples?
What are 5 other examples of drugs that are teratogens?
Something in system that should not be there at all
Examples: virus (e.g. rubella), Drugs (thalidomide)
1.accutane
2.warfarin
3.alcohol
4.nicotine
5.illicit drugs(cocaine,heroine,etc.)
73
What are 2 main principles of teratogens?
* Sensitivity to teratogen-induced malformation varies during different developmental stages and there are
critical periods of sensitivity to agents and organ systems.
* Teratogen-induced malformations occur in a dose-dependent manner, ranging from no observable defects
to total lethality.
74
What months of development are fetus' not affected by teratogens?
months 1 & 2
75
Where does the neural tube develop?
What does the neural tube form?
When is the neural tube at risk and what is the most important micronutrient during this time?
* In the middle of the ectoderm, a thickening of cells develops into the neural tube
* The neural tube forms the central nervous system(spinal cord, brain)
* During this formation, risk for neural tube defects
– Folic acid or folate (B-9) very important in reducing the risk for these defects
76
What happens when the anterior neural pore fails to close?
anencephaly
77
What happens when the posterior neural pore fails to close?
spina bifida
78
What are 3 factors that cause spina bifida?
Spina bifida likely results from a
combination of genetic (e.g. family
history) , nutritional (folate, blood
sugar levels) and environmental
factors (hyperthermia);
79
Can babies learn acoustic cues in the womb?
* Decasper and Spence (1986)
– 16 woman read one of three stories aloud during last 6.5 weeks of pregnancy
– Babies provided a nonnutritive soother
* One sucking pattern would trigger the previously read story
* One would trigger another story
– Story of choice was....
* Previously heard story
* Their conclusion was that babies could learn acoustic cues in the womb
80
What stage of development become more evident?
What type of environment does the fetus develop in?
What do genetics interact with in the postnatal environment?
* Variability becomes more evident
in postnatal development
* Fetus develops in a (relatively)
tightly controlled environment
* Postnatal environment is
increasingly variable →
– course set by genetics interacts
with many other constraints
– Landmark events, timing varies
among individuals
81
What are the 3 major components of the growth distance curve?
How does variability change with age?
* Sigmoid (s-shaped) growth pattern
* Rapid early growth
* Adolescent growth spurt
* Variability widens with age
82
What is weight susceptible to?
When does peak weight velocity follow peak height velocity in both boys and girls?
* Is more susceptible to extrinsic factors, especially diet and exercise.
* Individuals grow up, then fill out: Peak weight velocity follows peak height velocity by 2.5–5 months in boys,
3.5–10.5 months in girls).
83
What is the definition of relative growth?
Body as a whole follows sigmoid pattern; specific parts, tissues, and organs have different growth rates.
* Body proportions change from head-heavy, short-legged proportions at birth to adult proportions.
84
What do changes in body proportion affect?
How do body proportions differ between the genders?
* Changes in body proportions can
affect movement performance
* Example of recommendations by
Salmela and Durand-Bush for
gymnastics
* Differences in body proportions for
males and females:
– Males broader shoulders relative
to hips compared to females
85
What about lower body
relative to upper body; which sex
has more contributions to height
from the lower body (longer legs)
relative to the upper body?
Males
86
What are 3 examples of growth measures?
Is it difficult to infer maturity?
Do early maturer's or late maturer's tend to get taller and why?
* Height, weight, body proportions are
all growth measures
* It is difficult to infer maturity from age
alone, size alone, or age and size together.
* Specific maturational indices should
be used
* Individual variation in maturation
timing:
– Early maturer vs. late maturer
* Late maturers tend to get taller because the skeletal system has more time to contribute to linear growth.
* Early maturers generate a faster ossification process which can affect linear growth of the skeletal system.
87
What are 3 major maturational indices?
1. Tanner stages –classifies maturation in boys and girls into 5 stages based on secondary sex characteristics
– Average individual moves through the 5 stages in about 4 years (w/ individual variation)
– Based on direct assessment of breast, pubic hair, and genital development
– Females have menarche
2. Dental eruption
3. Ossification process
88
When are individuals most susceptible to extrinsic influences?
* Individuals are especially sensitive during periods of rapid growth.
* Catch-up growth
89
When do the peak velocity/peak height curves occur in both girls and boys?
What contributes to the greater height of males?
MINIMAL differences across early ages
Girls
Peak height velocity occurs at 11.5 to
12 years.
Growth in height tapers off around 14,
ends around 16.
Boys
Peak height velocity occurs at 13.5 to 14
years.
Growth in height tapers off around 17,
ends around 18.
Longer growth period of males contributes to their greater height
90
