10-18c Changes to Pediatric Bone & Muscle Flashcards
What factors affect skeletal growth, size, volume, structure, and function of the skeleton?
Growth, size, vol., structure, and function depend upon: Hormones Metabolic factors Nutrition Mechanical Forces over time Genetics Disease or Pathologic processes
growth: m. activation and activity
development and function: bone growth
What are the biochemical components of bone growth? What do they contribute to?
Growth Hormone, Insulin-like growth factor: longitudinal bone growth and mass
GH deficiencies: ^BMD
IGF also important for maitenance of BMC in adulthood
puberty and sex hormones: bone growth and development
TH: direct impact on bone metabolism (hypothyroidism = decreased bone lengthening
What do sex hormones (estrogens and androgens) lead to at puberty?
rapid longitudinal bone growth, fusion of physis, increased lean body mass, and contribute to significant variability
What are the growth factors in the bone? What do they do?
FGF: continually regulate skeletal patterning and bone growth throughout the skeletal growth period
What do vitamin D and calcium do?
Vitamin D becomes 125D, which is critical for intestinal absorption of Ca and ionic phosphate
What is limiting about Ca?
only 500 mg can be absorbed at one time
What measurements are key factors in age, growth, and development?
height, weight, BMI, skeletal maturity and sexual maturity
What are the typical growth scales based on?
height, weight, BMI
growth timing and velocity
What technique determines skeletal maturity/bone age?
All use left hand and wrist
Atlas technique of Greulich and Pyle: modal maturity indicators described for a specific age
What determines bone growth?
stature, growth velocity, timing, mass, and density
When do females reach peak height?
15 YO
When do females see an increase in growth velocity (height)?
from 9.5 to 10 YO
velocity is ~3.5 in/yr
When do males reach peak growth height?
18 YO
When do males increase in growth velocity (height)?
11.5 to 13 YO
velocity is ~3.7 in/year
When do females see closure of physis?
12.5 to 18 YO
When do males see closure of physis?
15-=> 18 YO
When do females reach peak bone growth velocity and completion of fusion?
11.5 YO
When do males reach peak bone growth velocity?
13.5 YO
How does age impact differential diagnosis?
fracture around growth plate differs depending on age due to fusion
onset for fusion is earlier in females
How many years after longitudinal growth do females have after first period?
two years
What is bone mineral content (mass)?
total bone tissue in an area
measured in grams
what is bone mineral density?
amount of bone tissue per volume
measured as g/cm squared or cubed
Peak bone mass?
maximal amount of bone tissue following skeletal maturation
What measures areal bone mineral density? Units?
DXA (g/cm squared)
What measures volumetric density of axial bone?
QCT (g/cm cubed)
What measures the bone density and mass for peripheral extremeties?
Peripheral QC
What does greater bone mass and density affect?
less likely for fragility fracture
What does a Z score act as?
percentile/standard deviation
In children 3 to 13 of equivalent weight, what is the diff b/w females and males?
females have greater quad muscles than males
What do males have more of at Tanner stage 5?
greater extremity lean soft tissue and total body skeleton m. mass
How does muscle strength correlate to factors in males and females aged 4-16? What does this suggest?
males: weight
females: weight and age
weight related m. reference data
at what phase ar females heavier, taller, and stronger?
11-13 yo
What ethnicity factors relate to bone density/longitudinal growth?
black children have longer legs and greater cross sectional area
What is true about US born children?
heavier and taller
How many SD are african american children than caucasian children in bone age? What may this represent?
0.5 SD
delayed bone age for african american children
advanced bone age for caucasian child
What is unique about pediatric skeletons?
preosseus cartilage, growth plates, periosteum (thicker, stronger), more shock absorption (lower BMC)
What are pediatric orthopedic concerns?
growth plate injuries (apophysitis), LE deformities, growing pains, pediatric fracture remodeling (better than adults)
Why are kids more likely to injure a growth plate than a ligament?
ligaments are attached to the epiphysis and hold on tight, so the force translates down towards the growth plates (less continuous fiber type: multi-segmental)
What are the four apophysitis diseases?
Osgood-Schlatter Syndrome:Traction injury due to tendon pulling periostenum away from bone at tibial tuberosity
Sinding-larsen-johansonn is the pull on the inferior patella
Sever’s Disease: Traction apophysitis of the posterior calcaneus
Iliac Apophysitis: Traction apophysitis along the iliac crest and/or spine
What are growing pains associated with? treatment?
hormonal factors that cause muscle strain during growth; instability at growing junctions
massage, hot or cold pack, analgesics
What are the major factors for bone remodeling following fracture?
age (younger the better they do), proximity to a joint (physis) the better it remodels, joint axis (deformity in the plane of primary osteokinematic motion)
problems: overgrowth, boyonet apposition to compensate
What are the requirements for youth resistance training programs?
specifically designed program, supervised setting, proper technique, safety guidelines
What are the results to youth training?
significant strength gains, decrease in skinfold measurements, changes in strength likely due to neural components
What factors contribute to injury in youth resistance training?
poorly designed programs, poorly supervised programs, excessive load, unqualified supervision, poorly designed equipment, free access to equipment
