bones, falls & fractures Flashcards
2 types of bone tissue
spongy or trabeculae
cortical bone
characteristics of trabeculae bone
porous
contains red bone marrow where blood cells are made
weaker and easier to fx
factors affecting bone strength
- bone density
- bone quality
- bone geometry
what is bone density
mass of bone per unit of volume
% of resistance of fx from bone density
50-80%
estimated rate of bone loss after menopause
1% and 2% per year for the first 10 years (later = dec 0.3 to 0.5%/year)
brittle bone disease
osteogenesis imperfecta
not enough collagen/abnormal
role to support the whole body
2 major components that inc structural integrity of bone
minerals
collagen
major minerals in bone ir order of quantity
1- calcium
2- magnesium
3- sodium
4- potassium
what do minerals provide to bone
rigidity and strength
what happens to collagen and mineral with aging
in our bones become less resistant to mechanical loading
what happens to bon geometry with aging
diameter of bone changes
which affects bone strength
larger diameter for same thickness is stronger then smaller diameter
what compensates for BMD loss in OA
process called peeriosteal apposition
what is periosteal apposition
the addition of tissue along the outer surface of the bone
what 3 factors can e affected by training (bone framework)
density
geometry
integrity
how is the bone strong and lightweight
interior made of bone fibers that crisscross each other in layers
align to carry the forces of tension and compression
osteopenia
condition characterized by lower then normal bone density; may be the precursor for osteoporosis
osteoporosis
a disease where bone mass and structure decline to a point where there is a significant inc in fragility and susceptibility to fx
established osteoporosis
preferred term for those with osteoporosis and having one or more fragility fractures
fragility fx
any fall form a standing height or less, that results in a fx
common areas of fragility fx
hip
spine
wrist
fraction of OA who recover from hip fx
less than 1/3
% of women suffering from hip fx
40%
change in posture with osteoporosis
kyphosis
7 principles for maximizing the influence of exercise on bone
1- bone adapts best to dynamic rather than static mechanical stim
2- if a bone is to respond to training, the stimulus be at a supra threshold level
3- the response of bone to exercise is improved by brief but intermittent exercise
4-bone responds best when the exercise employs a pattern that differs from usual loading pattern
5- the response that any bone has a mechanical stimulus such as exercise is proportional to the loading cycle (freq of stim)
6- for boe to adapt, it must have sufficient energy to rebuild itself
7-for exercise to work there should be abundant calcium and vitamin D availability
the message that tells bone to grow in response to mechanical loading is most likely from…
fluid flow through the canalicular channels and around the bone trabeculae
synonyme of bone growth
osteogenesis
what has greater effect on bone density
resistance training
intensity needed for rt and effect on bone growth
> 75% of 10 rep maximum
numb of days to split work performed for best osteogenic effect
5days/wk
what is imp to vary in RT programming
- amount of resistance
- method used to provide resistance
- directions in which the force is applied
the book drill
_-goal
- contraction
- variations
goal: balance training (ADL situation)
contraction: dynamice
variation: direction in which the force is applied
number of loading cycles with positive effects (max)
40 cycles
2 major dietary problems OA may face
low energy intake (especially low prot)
low calcium intake
role of calcium on bone
major raw mineral used to build bone, along w/ phosphate and mg
role of vitamin D on bone
vit D facilitates the absorption of calcium, phosphate, and magnesium ions through the intestinal wall and into the bloodstream
ACSM guidelines for preserving bone health in adulthood
- mode: weight-bearing endurance activities
- intensity: mod to high
- freq: weight-bearing endurance act 3-5x/wk AND resistance exercise 2-3x per week
- duration: 30-60 min/day
ACSM guidelines for elderly women and men w/ diagnosed osteoporosis
1-3 step 5-8 reps of 4-6 weight bearing exercises
- bw= resistance
- 2/3days /wk
- additional weight can be added w/ vest
- therabands & rubber tubing may be used to facilitate ROM
- avoid impact exercise, spinal flexion vs resistance, spinal ext, compression force, quick trunk rotation
Are compression fractures likely to cause nerve or spinal cord damage in OA with osteoporosis?
no
leading cause of injuries in 65+ canadians
falls
20-30% experience falls each year
cause of 95% of hip fx
20% cause death
falls and hospitalization
falls - 85% of hospitalizations in seniors
l
areas where fall occur most at home
stairs and bathroom
vicious cycle
fall = fear of falling = reduced PA = loss of m. mass and strength
= inc risk of fall
what dec with inc age
- nerve conduction velocity (10-15%)
- proprio @ foot and ankle (
- vestibular func (dizzy)
factors affecting the incidence of falls in OA
- impaired position sense
- foot position awarness
what can maximize foot proprio
footwear with low heals and thin, hard soles
age-related change in vision
- dec visual acuity
- loss of vision mainly due to anatomic changes in visual system
- vision loss
vision loss in OA
dec
- peripheral vision
- glare sensitivity
- dark adaptation
- depth perception
what is responsible for night vision
rods
functional implications of vision and hearing impairments
- well lighted area
- instruction spoken clearly and slowly
- instructior face participant and observe their comprehension
- external support for fall risk pt
