Body Systems of the First Year Flashcards
sway postural response strategies
ankle
hip
stepping
ANKLE STRATEGY
small perturbations
foot fully supported
Muscle activity begins distally
- LOB forward
- LOB backward
HIP STRATEGY
large perturbations
foot not fully supported
Muscle activity begins proximally
- LOB forward
- LOB backward
stepping strategy
perturbation too large to recover without protective step
postural response strategies depend on
Speed of perturbation
Degree of displacement (force)
Developmental stage
-Young children may not use best
4-6 yo: varying strategies
7-10 yo: Consistent ankle strategy, more timely
BALANCE
ability to maintain equilibrium
STABILITY
ability to resist movement disruptions
increase stability
Increase base of support
Lower center of gravity
Keep COG within BOS
↑ stability
↑ balance = ↓ mobility
musculoskeletal system year 1
Rapid bone growth & modeling
Factors affecting bone growth: Genetics Nutrition General health status Hormonal levels Physical activity
muscle year 1
Growth of skeletal fibers
- Increase in number of muscle fibers
- Increase in muscle fiber size
postural (spine) alignment year 1
Cervical lordosis
-More evident with improved head control
Lumbar lordosis
-More pronounced with sitting and anti-gravity skills
hip alignment year 1
Development of the Femur
Newborns: start in retroversion
Children: more anteversion than adults
Adults: Progress to slight anteversion
angle of inclination
Starts out straight then angles with weight bearing
Angle decreases with typical WB
(B) Obesity in childhood → Coxa vara → early onset OA
(C) Decreased WB in childhood → Coxa valga → subluxation/ dislocation
acetabular index
More coverage of femoral head
Larger angle indicates ↓ WB
knee alignment
Femur to Tibia relationship:
Genu varum to neutral
Increased walking & W/B:
Progresses to genu valgus
Typical adults:
Slight genu vagus
foot alignment
Newborn
Calcaneal varus →
slowly progress to neutral
sequence of ossification of the tarsal bones
metatarsals and phalanges: 9-12 weeks calcaneus: 4-7 months talus: 6 months cuboid: around birth lateral cuneiform: during year 1 medial cuneiform: during year 2 intermediate cuneiform: during year 3 navicular: during year 3 after intermediate cuneiform
standing 1-2 years old
When a child begins to stand -Physiologicalflat foot -With hindfoot valgus -Due toflexibilityof thejoints Increased subcutaneous fat -Fat pad Pediatric feet -Generally flexible -Hypermobile
feet 3-5 years
3 yo: Navicular ossification
3 – 4 yo:
Flexibility decreases
Subcutaneous fatdecreases
Medial longitudinal arch begins to form
4 – 5 yo : Longitudinal arch = adult-like shape
it is normal for young children to have flat feet
nervous system year 1
Brain Growth
- At birth, 25% of its adult -weight
- At one year, 60% of its adult weight
Critical brain growth
-Between 3 months & 2 years of age
Early brain growth coincides:
- Cognitive development
- Language development
myelination year 1
Myelination of CNS
- Continues into young adulthood
- Slows considerably after 2 yo
Myelination of PNS
- Mostly complete at birth
- Immediate access to environmental sensory info
cardiovascular system year 1
Heart size increases
Mature muscle fibers contract with more force
Heart muscle vascularization increases
Arteries & veins increase in size
respiratory system year 1
At birth: fraction of total alveoli present
New alveoli develop until 8-10 yo
Airways increase in length & diameter
Bronchioles & alveoli become stronger/more efficient
Newborns: highest respiratory rates
Infants & young children
Higher energy cost of respiration than adults
Less efficient coordination of respiratory muscles
respiratory system infants and young children
Barrel chest with flared ribs
Abdominals are weaker
Less resistance to pull of diaphragm
Increased risk of infection & atelectasis
hallmark motor milestones
4-6 mo: Rolls prone to supine 4-6 mo: Rolls supine to prone 6-7 mo: Sits alone 8-10 mo: Creeps on hands & knees 12 mo: Walks alone
cephalocaudal development
First quarter of first year of life
Control of head in all positions in space
Second quarter of first year of life
Control of arms and upper trunk
Third quarter of first year of life
Control of lower trunk and pelvis in the upright position
Fourth quarter of first year of life
Control and mobility of the lower parts of the legs in upright stance
functional head control
Birth
Vertical head position only sustainable for 1-2 sec.
Can turn head to clear airway
3 months
Synergistic control of neck flexors and extensors
Stable vertical head position
Able to turn head freely
4 months
Organized eye-head-hand control seen in prone
Lack of/decreased head control
upright trunk control
4 months Prone Extending the head and trunk Legs and pelvis are load-bearing Caudal weight shift
6 months
Independent sitting with object manipulation achieved
lower trunk control in the upright position
Control of lower trunk and pelvis allows for:
7 mo. – Crawling & creeping
8 mo – Pulling to stand
8 mo – Moving in and out of quadruped and sitting
Freedom from midline symmetry
Rotational abilities
fine lower extremity control
Control of trunk and pelvis
Reciprocal lower extremity movement
8-9 mo – Creeping
9-11 mo – Supported walking
11 – 15 mo – Independent walking
developmental sequence
Follows predictable sequence/pattern
Universality
Predictable patterns
Variability
Individual differences
Cultural
e.g. Establishing PT plan of care
