Developmental Biomechanics Flashcards
Wolfs law
mechanical stresses can modulate bone shape and internal architecture
when does skeletal ossification occur
3-25 years
newborns have a anterior/posterior tilt
posterior tilt
what age does the posterior tilt changes to more of an anterior tilt?
3-5 ages
Most adults have a normal anterior til of what
8-13 males
10-22 females
Coxa valga
increased angle of inclination greater than 135
Normal femoral neck angle of inclination
125
coxa vara
decreased angle of inclination less than 125
Do children have coxa valga or coxa vara
Coxa valga at 1 year declines at year 4
greater hip medial rotation compared to lateral rotation is suspect for _______ femoral anteversion
increased
what are the norms for medial rotation at 1 year and 5 years
20-40 degrees (1 year)
30-50 degrees (5 years)
what are the norms for lateral rotation at 1 year and 5 years
50-80 degrees (1 year)
30-50 degrees (5 years)
Do newborns typically have more medial rotation or lateral rotation
lateral rotation
Anteverted hip will lead to what at the foot
toeing in pigeon toes
Retroverted hip will lead to what at the foot
toeing out duck feet
Craigs test is used to measure what
femoral anteversion
If the newborn has a high degree of femoral antetorsion why do they appear laterally rotated at the hip?
soft tissue contracture in hip flexion, lateral rotation
infants have more lateral hip rotation than medial
retroverted and shallow acetabulum
How does the acetabular shelf form and femoral ateversion decrease
muscle tension and weight bearing
Activities that apply hip extension, rotation and abduction force
newborn: kicking, 4 point, crawling, standing
Anteversion improves with time and reaches the peak of improvement possibly around the age of _____
6 years
What activities could you encourage a child to do to promote use of external rotators
scootering
rollerblading
ice skating
3 year olds have typically knee valgus or varus
valgus knock kneed
How do you measure the knee varus/valgus (tibiofemoral angle)
flex and extend both knees in frontal plane and measure the space between the malleoli
the intramalleolar space should increase/decrease from birth to 9 years?
no space varus
3-5 large valgus
5 to adult small moderate varus
What is the foot progression angle
angle between the longitudinal axis of the foot and the line of progression of gait
a negative value on foot progression angle is typical/atypical
not typical
Tibial torsion
is rare the rotation is a problem except in diseases like blounts disease
what is typical transmalleolar axis
with knee in frontal plane, medial malleoli typically rotated more forward than lateral
What is the tibio-femoral rotation
range of movement that occurs in the transverse plane at the knee joint
often confused with tibial torsion
What can we do to de-rotate at the hip/knee
twister straps
theratogs
What is the clinical presentation of someone with a flat foot
decreased arch height in standing
lateral forefoot deviation
often genu valgus
confusion of medial fat pad for collapsed navicular
associated with hypotonia, ligamentous laxity and sensory seekers
When is typical arch development
between 2-6 years of age
Treatment of flat foot
younger patients
-generally not necessary to treat
-shoe inserts generally not beneficial
-shoes with arches and firm counter help decrease number of shoe purchased
-working on improving lower trunk and proximal hip strength
What are 4 possible reasons for in-toing
hip: increased femoral antiversion 5-6 year olds
knee: toddlers
increased tibial torsion - rare
increased axial tibio-femoral rotation- w sitting
Foot: metatarsus adductus: babies
Babies hypothesis for in toeing
metatarsus adductus
toddler/preschooler hypothesis for in toeing
knee increased axial tibiofemoral rotation
school age hypothesis for in toeing
femoral antiversion
From birth to early childhood what decreases
foot progression angle
femoral antivesion
calcaneal eversion standing
birth to adulthood change in sacral angle
posterior to anterior
birth to adulthood change in acetabulum
retroverted to anteverted
birth to adulthood change in coxa vera and valga
valga to vera
birth to adulthood change in ateversion
decreased from 40 to 8-15
hip ER from birth to adulthood
decreased
hip flexion birth to adulthood
contracture to full hip extension
genu varum to valgum
varum to valgum
foot progression angle from birth to adulthood
decreases
axial tibiofemoral rotation birth to adulthood
decreases
Arch development from birth to adulthood
increases
