Posture 0-12mo Flashcards
What forces contribute to final bone shaping?
Longitudinal (compression/tension)
Shear (torsion/twisting)
Acetabulum is ___ at birth, which increases the risk of ___
shallow
hip dislocations
What helps keep the femoral head in the acetabulum at birth?
physiologic hip flexion
Antetorsion
head and neck of the femur are rotated fwd in the transverse plane relative to fem condyles.
More common type of torsional deformity.
Antetorsion is associated with
in-toeing
w-sitting
Retrotorsion
head and neck of the femur are rotated posteriorly in the transverse plane relative to fem condyles.
Torsion at birth vs adult
Birth = 30-40deg ante Adult = 12deg ante
Version
position of the femoral head in the acetabulum (how far off frontal plane)
How is femoral version tested?
Hip rotation ROM
Not accurate for below 3yo bc they have tighter ABD & ER muscles.
What indicates femoral anteversion?
IR is significantly»_space; than ER
If difference is >45deg = abnormally high anteversion.
What indicates femoral retroversion?
ER is signifiantly»_space; than IR
If difference is >50deg = abnormally low anteversion.
Characteristics of persistent antetorsion/anteversion
W sitting
Running w/ legs swinging out
Often trip/fall
In-toe (pigeon-toe) walking - tibial torsion
Knee - newborn
moderate varum
Knee - 6 months
mild varum (due to active movement & gravity)
Knee - 1yr to 18mo
straight (due to WB)
Knee - 2.5yo
slight valgus
Knee - adulthood
Females = slight valgum Males = slight varum
Postural control is achieved by the cooperation of…
sensory system
MSK system
motor control system
An infant begins to use vision to drive muscle activation of the neck in supported sitting at age ____
4-6 days
At age ____, develops the ability to resolve sensory conflict to maintain balance
2-10yr
At age ___, start to use somatosensory info to balance head & trunk
6mo
At age ____, start using somatosensory info to resolve sensory conflict in standing
4-6yr
Reactive Postural Adjustments (RPAs)
closed-loop system
body receives input & responds accordingly
RPA example
flexing neck & hip flexors to prevent from falling backwards
Anticipatory Postural Adjustments (APAs)
open-loop system
minimize potential postural disturbances with movement initiation.
assist in achieving desired movment.
RPA at age 5-6mo
activate agonist muscles in the direction opposite that they are falling
RPA at age 10-12mo
activate muscles in a similar pattern as adults in standing
APA at age 6-8mo
activation of trunk muscles before activation of arms
APA at age 3-5yr
similar to adult-like activity in standing
Righting rxn
moving head to keep eyes on the horizon
maintaining/restoring alignment of body segments in relation to each other
Equilibrium rxn
occurs when COM shifts out of BOS
can occur as an RPA - as a response to external stim such as losing balance.
can occur as an APA - preparing movement, such as going into SL stance.
ex) torso elongates on WB side & lat flex on NWB side during SL stance.
Head righting 0-4mo
when head turns to one side, body log rolls
Head righting 4mo & on
when head turns to one side: roll becomes more segmental, rolling starts with the shoulders & ends with the pelvis
Body righting 4mo - 5yr
stimulus: one leg lifted & pelvis rotates.
response: roll supine to prone with pelvic rotation, then shoulder, then head
Labyrinth righting (any age)
hold infant vertically, tilt to one side.
infant will tilt head to keep eyes level w/ horizon
Landau righting (what is it & what age)
infant held in prone (suspended off floor)
activates trunk/cervical ext to keep eyes on horizon
begins at age 3-4mo & lasts until 1-2yr
how are equilibrium rxns different from righting rxns?
Equilibrium = total body response, more sophisticated than righting.
lateral sitting equilibrium rxn
shift wt to one side in sitting
head & trunk lat flex
arm/leg ABD opposite the side of wt shift
head & trunk rotate toward abducted extremities
Cephalocaudal development: 1st quarter
develop control of head in all positions in space
Cephalocaudal development: 2nd quarter
advanced control of arms & upper trunk
Cephalocaudal development: 3rd quarter
master control of lower trunk
pelvis in upright position
Cephalocaudal development: 4th quarter
develop mobility/control of lower legs in upright stance.
improvements in overall postural ctrl
Hierarchial model
postural reflexes & automatic rxns are inhibited to allow activation of voluntary systems (only focuses on CNS maturation)
Dynamic systems model
rate-lim factors either facilitate or constrain the emergence of motor skills
Order of development of planes of motion
Sagittal (flex/ext) first
Frontal (lat flex) second
Transverse (rotation) last
General Spontaneous Movements
endogenously generated by central pattern generators (CPGs from lecture 1).
assessing spontaneous activity can help identify brain dysfunction & neuro impairments (greater sensitivity than ultrasound)
3-4mo normal movement quality
fidgety movements - continuous stream of tiny, elegant movements occuring irregularly all over the body.
3-4mo abnormal movement quality
absence of fidgety movements.
movements lack fluency, complexity, & variation.
