Motor learning and development

Topics 1-4

Degrees of freedom problem

The brain must control and coordinate aspects of movement to create motion

Degrees of freedom problem refers to…

the number of independent variables or ways a system can move

Degrees of freedom problem includes what aspects of the body?

Joints, muscles, and body segments

How many degrees of freedom does the wrist have?

Two

Degrees of freedom problem example

Cartwheel

Certain joints/muscles are constrained and released throughout movement

Serial order problem

To produce movement, sequence and timing must be correct

Serial order problem: mistakes in order can lead to…

error in action

Serial order problem example

Playing the piano

Example of error in serial order

Accidently throwing socks into a trash can

Perceptual-motor integration problem

Movement is dependent on perception

Perception of the environment allows…

proper movement

Perceptual-motor integration problem example

Writing on lined paper - hand-eye coordination

Mirror neurons

Neurons that fire when observing someone doing something or when doing something yourself.

Where are mirror neurons located?

Motor and premotor areas of the frontal lobe

How are mirror neurons involved in motor learning and motor control?

They create a mental copy of what we see, letting us “practice” the action in our mind.

The brain stores the steps needed to perform the action later.

Motor skill

Function that involves specific movements of the body’s muscles to perform a certain task

Action goal, voluntary, learned or relearned

Motor skills

Motor skill performance

Individual + Environment + Task/Skill

Gross-Fine

Continuous-Serial-Discrete

Open-Closed

Self-paced vs Externally paced

One dimensional classifications of motor skills

Gross and fine motor skills are based on…

size of the muscle

Gross motor skills

Large muscle groups

Basic movements

Gross motor skill example

Walking

Fine motor skills

Smaller muscle groups

Refined/precise movements

Fine motor skill example

Playing an instrument

Which one-dimensional classifications of motor skills are on a continuum?

Gross-Fine

Continuous-Serial-Discrete

Continuous, Serial, and Discrete motor skills are based on…

task organization and specificity of where movements start and end

Continuous motor skills

No defined beginning or end

Sustained over a longer period

Continuous motor skill example

Cycling

Serial motor skills

Group of discrete movements strung together

Order is crucial

Serial motor skill example

Figure skating routine

Discrete motor skills

Defined beginning and end

Often quick and deliberate

Discrete motor skill example

back walkover in gymnastics

Open-Closed motor skills

Based on the stability of environmental context

Whether features in the environment influence how you move

Supporting surface, objects, other people

Examples of environmental context in open-closed motor skills

Open motor skills

Unstable/changing relevant environmental context features, adaptations to external cues

Open motor skill example

Practicing ice skating in a rink with others

Closed motor skills

Stable relevant environmental contexts features, internally paced

Closed motor skill example

Running on an empty track

Self-paced (internally paced) motor skills

Mover initiates and controls timing and speed of movement

Self-paced motor skill example

Golfer deciding when to swing

Externally paced motor skills

Mover is responding to something, timing in dictated by external factors such as the environment or other people

Externally paced motor skill example

Shooting a basketball during a game

Dimensions in Gentiles two-dimensional taxonomy

Environmental context

Action function

Environmental context includes…

Regulatory conditions and intertrial variability

Regulatory conditions

Environmental features that determine how the skill must be performed

Regulatory conditions include…

Stationary and In-motion

Stationary regulatory conditions

The environment does not change during the skills execution

Stationary regulatory condition example

A still target

In-motion regulatory conditions

The environment is changing, requires constant adjustment from performer.

In-motion regulatory condition example

Moving ball

Inter-trial variability

Indicates whether the requirements of the task change from one attempt to the next

Absent inter-trial variability

A skill is performed the same way each time

Absent inter-trial variability example

Free throw

Present inter-trial variability

The skill requirements vary between trials

Present inter-trial variability example

Returning a serve in tennis

Action function includes

Body orientation and object manipulation

Body orientation includes

Body stability

body transport

Object manipulation includes

No object manipulation

Object manipulation

Body orientation

Refers to whether the performer moves from one location to another during the skill

Body stability

The body remains in one place

Body stability example

Hitting a baseball

Body transport

The body changes location

Body transport example

Running between bases

Object manipulation

Addresses whether the performer controls an object as part of the skill

No object manipulation

The skill does not involve manipulating an object

No object manipulation example

Jumping

Object manipulation

The skill requires controlling an object

Object manipulation example

Jumping rope

Motor ability

Innate, genetically determined traits that influence and individuals potential for movement

Motor ability example(s)

Agility

Coordination

Strength

How are motor abilities related to motor performance?

Set the upper limits for a persons performance, provide foundation for skills.

Three stages of prenatal development

Germinal period

Embryonic period

Fetal period

Germinal period timeline

Conception to second week

Germinal period physiological changes

Formation of zygote and rapid cell development

What does the zygote do during the germinal period?

Travels down fallopian tube and embeds in uterine wall

During the germinal period about 50% of fertilized eggs…

are spontaneously aborted

Embryonic period timeline

2nd to 8th week

Embryonic period physiological changes

Zygote becomes an embryo

Cells differentiate into three primary layers

Organogenesis marks the … period of prenatal development

Embryonic

Organogenesis

Differentiation of cells into three primary layers

Three primary layers of organogenesis

Ectoderm

Mesoderm

Endoderm

Ectoderm

Develops into nervous system and sense organs

Mesoderm

Forms muscles, bones, and the circulatory system

Endoderm

Gives rise to the digestive system and glandular systems

In what stage do the placenta and amnion form?

Embryonic period

What is function of the placenta and amnion to the embryo?

Support and protect

By the 4th week of prenatal development…

limb buds appear

By the 8th week of prenatal development…

the embryo begins to resemble a human form

Fetal period timeline

8 weeks to birth

What is the embryo called in the fetal period

Fetus

Two key process of development during the fetal period

Hyperplasia

Hypertrophy

Hyperplasia (prenatal development)

Increase in cell number

Hypertrophy (prenatal development)

Increase in cell size

Prenatal growth follows two directional patterns

Cephalocaudal

Proximodistal

Cephalocaudal growth

From head to toes

Proximodistal growth

From the center of the body outwards

Plasticity (prenatal development)

Cells are influenced by experiences and can adapt their function based on environmental input

Placenta function

Allows for the exchange of oxygen, nutrients, and waste products through diffusion

The placenta prevents

Maternal and fetal blood from mixing

Small molecules that can cross the placental barrier

Drugs, viruses, and toxins