Motor Development Final: cumulative material

Define motor development

how to develop motor skills

- requires motor learning

define motor learning

adaptions that occur from practicing or performing movement

- movement changes related to experience or practice, not age

define motor behavior

result or consequence of motor development and/or learning

define motor control

control of body systems, especially nervous or skeletal, allowing movement to be precise and well-controlled

define embryology

branch of biology that deals with formation, early growth, and development of living organisms

When does a fetus begin to move

8-10 weeks after conception

*in utero movement is critical for development

How long is a normal gestation

40 weeks

What does the prenatal period begin with

fertilization

How many chromosomes does a healthy baby have

46 pairs (23 from mom and 23 from dad)

What are the 3 stages of prenatal developement

- germinal period

- embryonic period

- fetal period

When is the germinal period

first 2 weeks after conception

What is a zygote

fertilized ovum (ovum is a reproductive cell)

A zygote will develop into a...

blastomere once it has 12-16 identical cells

What are the 2 layers that a blastomere develops

trophoblast and blastocyst

what is a trophoblast

outer layer of a blastocyst that forms the placenta, anion, and amniotic sac

What is a blastocyst?

hollow ball of cells that embeds into the endometrium of the uterus for development

When is the embryonic period

weeks 3-8

What is the embryonic period also known as

organogenesis

what is organogensis

Period in embryonic development where cells develop into body organs and systems

- means that issues during this period can be detrimental

- most congenital defects develop in the first 8 weeks after conception

3 layers of the inner blastocyst

endodermal, mesodermal, ectodermal

The endodermal layer becomes the

digestive and respiratory tracts

The mesodermal layer becomes the

muscles, skeletal system, circulatory system, reproductive system, and dermis

The ectodermal layer becomes the

CNS, PNS< sensory system (eyes/ears), mammary glands, and outer skin layer

T/f the CNS is one of the first organ systems to form

true

When does the neural tube develop

by the 3rd week

When does fusion of the neural tube occur

21-28 days

Describe neural tube development

After implantation, the blastocyst develops into three germ layers: ectoderm, mesoderm, and endoderm. The ectoderm thickens to form the neural plate. As development continues, the neural plate folds inward, forming neural folds that elevate and move toward the midline. These folds fuse to form the neural tube, which is the precursor to the central nervous system. The neural tube initially develops as two separate sides, and fusion (closure) occurs between days 21-28 of embryonic development.

what is primary neuralation

Primary neurulation is the process by which the neural tube forms from the ectoderm, giving rise to the brain and spinal cord down to about the upper sacral level.

Where does primary neuralation begin?

occipital-cervical area and proceeds caudally to cranially

What nutrient is critical for neural tube fusion

folic acid

* must be at optimal level prior to conception. So they added it to bread

The difference between spina bifida and anencephaly

Spina Bifida: failure of closure of the neural tube caudally

Anencephaly: failure of closure of the neural tube cranially

Describe CMV

Cytomegalovirus (CMV) is part of the herpes family

- Toddlers often carry CMV and affect mother. CMV can cross the placenta

- Can lead to brain damage, hearing impairments, visual impairments, Microcephaly, and intracranial calcification

The first muscular activity in the embryo is what and when does it occur?

The heart begins beating at 22 days.

When does the heart complete its development

36-42 days. The heart has 4 chambers by 49 days

Describe myogenic movements

Striate muscle reacts to local stimulation, not nervous or external stimulation

- Muscle contraction is due to direct stimulation because the nervous system is not yet fully developed

Describe limb development

At 26 days, arm buds

At 28 days, leg buds

Forelimbs develop at 29-35 days

Hands and feet develop as webbed mittens initially

When is the fetal period?

9 weeks to birth

What is the fetal period also known for

neurogenesis: a period of cellular and neural development

When does myelination occur?

16wks and continues post-natally

What is migration

neurons travel and spread out to the cortex and other areas to/ form the nervous system

Neurons migrate at 3-5 months

Glial cells migrate at 5-8 months

When do neurogenic movements occur

20wks

When does the cerebellum develop

Last to mature; incubates until 40 wks

Arthrogryposis:

Arthrogryposis: a condition characterized by congenital stiffness and fixed contractures of two or more joints, caused by reduced or absent fetal movement in utero

- often become very creative and bright children

Hypoplasia/ agenesis of corpus callosum or Gyral abnormalities: effects

can result in Ataxia, and or deficits in visuospatial, attention, and language. (corpus callosum/ gyri don't form at all or don't fully form)

Fetal period: Respiratory development

The respiratory system develops from the endoderm layer of the blastocyst

At 17-20 weeks, the air sacs begin to develop, and the capillary beds are forming

By 25-29 weeks, the lung has improved ability for gas exchange

What sensory system develops first? What is last?

- tactile/propriception (somatosensory) is the first to develop

- Vestibular

- taste/smell (chemoreceptive)

- Auditory

- Visual: last to develop

What must occur in the uterus for the baby to be normal

baby must be moving for normal development to occur

What are the 5 theories of development

1. maturation

2. learning

3. ecological

4. dynamic systems

5. neuronal group selection

What is the maturation theory

Key concept: Once the brain fully develops, motor development advances

Early motor control is the result of reflexes and the structure/organization of CNS

The neurological anatomic changes having occurred lead to changes in motor behavior

What is the learning theory

Environment/ external forces shape behavior

Response chaining: feedback from one movement activates the next movement

Motor skills are learned through classic and operant conditioning, like pavlovs dogs

Skills are learned through trial and error, as they are repeated

What is the ecological theory

Relationship between the individual, the task, and the environment

Includes culture, economics, and societal influences

Movement shapes perception, and perception guides future movement

What is the dynamic systems theory

Multiple variables initiate and drive movement

Motor behavior is a concert between neural, biomechanical, and environmental factors

Your body, body systems, and environment are actively engageing to complete a task

What is the neuronal group selection theory

Relationship between movement dynamics and brain structure-function: how you move shapes how the brain is organized, and how the brain is organized shapes movement.

- Brain development and changes occur from experience

- Sensory information provides motive

Why do we study motor development

We study infant and baby movement patterns to help treat in pediatrics, but we also study these things because adults or people with neurological disorders often revert back to immature movement patterns

Name the 5 basic principles of motor development

- Neural maturation is important for skill development

- Neural development is stage-like and continuous

- Postural control is essential

- Development is a collaboration of all body systems

- There is alternation between stability and instability towards function with switches between symmetry and asymmetry

the development of normal antigravity posture and movement occurs in an....

orderly and predictable fashion

The development of normal antigravity posture and movement depends on the ability to combine...

combine patterns of movement in the performance of functional activity.

The development of normal antigravity posture and movement requires the ability to

control the body's center of gravity and adjust the point of stability 

define center of gravity

Center of gravity (COG): where gravity is most stabilized

define base of support

Base of support (BOS): Part of the body that stabilizes your COG

define point of stability

Point of stability (POS) is usually a part of the base of support. If you remove it, the baby will fall

The development of normal antigravity posture and movement depends on the development of...

of normal musculoskeletal relationships and alignment.

Example: As the baby begins to walk, the lower extremities change. By 7-8 years of age, hip seating (mature development) occurs.

Normal alignment should be achieved by 1 year of age. Normal weight-bearing and muscle pull realign the femur. Normal movement development drives musculoskeletal changes

The development of normal antigravity posture and movement depends upon normal ______ compliance and the development and maintenance of normal _____ ______

The development of normal antigravity posture and movement depends upon normal tissue compliance and the development and maintenance of normal muscle tone

define muscle tone

Muscle tone: the resting state of the muscle, measured by resistance to passive stretch

Hypertonia

Hypertonia: increased resistance to passive stretch.

Examples: rigidity and spasticity

Spasticity

Spasticity: increased resistance is velocity-dependent stretch. Faster you move, the tighter the muscles get

Rigidity

Rigidity: resistance is constant regardless of the speed of movement. It doesn't matter how quick you move, the muscles are tight

define hypotonia

Hypotonia: decreased resistance to passive stretch. Flaccid or floppy

Premature babies are often hypotonic

The development of normal antigravity posture and movement depends on the development of _____ and _______

mobility and stability

When learning a skill, at first you will be very mobile, but over time you become stable

Stability progresses through 3 stages, which are?

- structural stability

- positional stability

- internal stability

Structural stability

Structural stability: a result of soft tissue shortening due to physiological flexion

positional stability

Something has to help position the baby for them to be stable/ get into that position.

- Use of the body to provide self-support until internal stability is gained

internal stability

Internal stability: Occurs first with sitting. Baby no longer has to prop themselves up and is able to move head/ hands, stable and balanced against gravity

- Internal control mechanisms to maintain posture without the need for positional stability

The development of normal antigravity posture and movement progresses through 4 stages. Once developed, normal activities move back and forth between the stages. What are those stages?

1. Mobility

2. stability

3. controlled mobility: transitions in and out of postures, both static and dynamic work

4. skill

The development of normal antigravity posture and movement requires the ability to affect and manage a

The development of normal antigravity posture and movement requires the ability to affect and manage a weight shift.

- skills begin developing at 5m and refine by 5 years

Describe the progression of development

- Begins at the head and finishes at the toes (Cephalocaudal )

- Occurs proximal to distal

- Gain gross motor skills before fine motor skills

- Early movement is random, spontaneous, and non-purposeful

- All babies develop in physiological flexion

Describe a mature, normal loading response

Mature: elongation on the weighted side, and shortening on the unweighted side

Describe an immature loading response

shortening on the weighted side, elongation on the unweighted side

How does random spontaneous movement, like kicking, help the baby develop

Since the muscle is already at its shortest length (physiological flexion), the baby will kick into extension to lengthen the muscle and learn contraction

What are the early movement patterns

- random, spontaneous, non purposeful

- bilateral symmetry

- alternate reciprocal movement

- unilateral symmetry

- diaganol reciprocal

bilateral symmetry

The left and right neck extensors contract to hold up the baby head

alternate reciprocal movement

- Requires CNS maturation and strength

- Baby can do asymmetrical movement

- One side is working, while the other side relaxes. Either right or left, either front or back

- Flexors of the left side fire, then the right side fires

unilateral symmetrical

- Both muscle sets on one side of the body are firing.

- Extensors and flexors of the left side are firing

diagonal reciprocal

most mature response

- Flexors on one side and extensors on the other side are working together

- Mature response, first seen in sitting

- Requires the most CNS coordination

describe APGAR

APGAR: looks at multiple factors, including color, pulse, facial movements, and respiration. Scoring each a 0,1,2, evey minute for 5 minutes to assess the baby's health

OLD reflex theory states that

as the brain begins to assume voluntary control over motor function, reflexes are inhibited or form the basis of functional movement

- Reflexes dominate newborn movement, and motor control comes from inhibiting reflexes and replacing them with voluntary movement

NEW reflex theory states that

reflexes provide a framework for movement, but do not address the dynamic adaptive nature of the newborn

- Reflexes can be modified by the brain to produce the most appropriate and efficient movement for a task

Rooting reflex

Action: stroke the baby's cheek while they are supine

Response: infant turns head toward stimulation

Age: birth to 3m

sucking reflex

Action: stimulates the upper or lower lip with a finger/pacifier

Response: baby opens mouth to suck in finger/pacifier

Age: birth to 3m

Moro reflex

Action: drop the baby back 20-30 degrees

Response: baby will flai arms out then bring them in

Age: birth to 6m

Palmar grasp

Action: while the baby is in supine, put your finger into the baby's hand, coming from the ulnar side

Response: infant's fingers flex around yours

Age: birth to 3-4m

plantar reflex

Action: with the baby in supine, stimulate the lateral and plantar aspects of the foot with an object

Response: baby's toes fan out through dorsiflexion and extension

Age: birth to 12-24m

babinski reflex

Action: stroke the sole of the foot from heel to toe with an object

Response: from birth to 24m, toes should fan out. However, after that, there should be no movement

flexor withdrawal reflex

Action: While the baby is relaxed in supine, pinprick or pinch the sole of the foot

Response: The baby will withdraw the foot

Age: birth to 4 months

crossed extensor reflex

Action: while the baby is relaxed in supine, pinprick or pinch the sole of the foot

Response: flexor withdraw will occur on the effect foot, the opposite foot will extend outward

Age: birth to 4m

Spontaneous stepping reflex

Action: Support the baby in a standing position, then tilt the infant forward and move them forward

Response: baby will weight bear and step alternatively and rhythmically

Age: birth to 1-2m

Asymmetrical Tonic Neck Reflex (ATNR)

Action: while the baby is in supine, slowly rotate the head to the side and hold the position

Response: arm and leg on the side where the head is turned will be extended, while the opposite side will flex (fencing position)

Age: 1-2m to 3-4 m

Symmetrical tonic neck reflex:

Action: place the baby in a prone position over your thigh, then passively move their head from flexion into extension

Response: In flexion, the baby's arms flex and legs extend. In extension, the baby's arms extend, and the legs flex

Age: 5m - 6m

Tonic labyrinthine reflex

Action: While the baby is in supine, push the infant into a sitting position and assess their extension. WIth baby in a prone position and head looking one direction, lift head into extension

Response: if positive, the baby will push head and trunk into extension. In the prone position, the baby's head will push into flexion

Age: premature infants, possibility lasting until 6 months in term infants

Labyrinethine head righting:

Action: While holding the baby, blindfold him, and holding it under their arms, tilt the baby forward, backward, and sideways

Response: Baby will vertically orient their head with their mouth horizontal

Age: birth to 4m (optical righting measures take over after this)