Lecture 10: Bones, Falls and Fractures Flashcards
What is the outer layer of bone?
What is the inner layer of bone?
Outer = Compact bone Inner = Spongy or Cancellous
What is Spongy/Trabecular/Cancellous bone
It is one of the two types of bone tissue found in the body. It is very porous and contains red bone marrow, where blood cells are made. It is weaker and easier to fracture than cortical bone.
What are the 3 factors affecting bone strength
- Bone density
- Bone quality
- Bone geometry
What is bone density?
Accounts for what percentage of bones resistance to fracture
What is the estimated rate of bone loss after menopause?
- Bone density is the mass of bone per unit of volume
- 50-80%
- 1% and 2% per year for the first 10 years and later a decline in less than .3-.5%/year
What is bone quality
Structural material from which bone is constructed
What are the 2 major components that increase the structural integrity of bone
- Collagen
2. Minerals
What are the major mineral in order of quantity and what do they provide
- Calcium
- Magnesium
- Sodium
- Potassium
Provide rigidity and strength
With aging collagen and minerals in our bones becomes __________ to mechanical loading
With aging collagen and minerals in our bones becomes less resistance to mechanical loading
What is bone geometry
As we age the diameter of our bones changes and this affects out bones strength
In OA the loss of BMD is compensated by a process called __________ which is_______?
In OA the loss of BMD is compensated by a process called periosteal deposition which is the addition of tissue along the outer surface of the bone
True or False: For the same bone thickness, the bone with the greater diameter is more solid vs. smaller diameter
True
What is the roof trusses and bone
A comparison of normal, osteoporotic and trained bone matrix
What is normal bone analogous to
A standard roof truss - healthy trabecular bone
What is osteoporosis bone analogous to
Roof truss with structural bracing missing. reduction in the number and size of bridges and the increase in resorption cavities which reduce bone strength.
Inc space in cavities
Dec size
Dec in # of bridges
What is trained bone matrix analogous to
Roof truss with added bracing for greater strength
Inc in size
Inc # of bridges
Dec space in cavities
The strength of bone is affected by more than its density. It is also affected by the ______ and ______ of the bones framework. Training can affect all 3 factors
The strength of bone is affected by more than its density. It is also affected by the Geometry and Integrity of the bones framework. Training can affect all 3 factors
What is osteopenia
A condition characterized by lower than normal bone density; may be the precursor for osteoporosis
-1 - -2.5 SD below the mean
What is osteoporosis
A disease where bone mass and structure decline to a point where there is significant increase in fragility and susceptibility to fracture
less than or equal to -2.5 SD below the mean
What is established osteoporosis
Those with osteoporosis and one or more fragility fractures
OA suffering hip fractures often experience a loss of independence; less than _______ of those who fracture their hips recover sufficiently to perform basic ADLs
OA suffering hip fractures often experience a loss of independence; less than 1/3 of those who fracture their hips recover sufficiently to perform basic ADLs
What percentage of woman sustain a fracture during their life time
40%
What are the 3 most common sites for fractures
- Hip
- Wrist
- Spine (compression)
What is a fragility fracture
any fall from a standing height or less that results in a fracture
The body should be able to sustain a fall from this height without a fracture unless there is an underlying cause that makes the bones fragile
What are the 7 principles for maximizing the influence of exercise on bone?
- Bone adapts best to dynamic rather than static mechanical stimulation
- If a bone is to respond to training, the stimulus must be at a suprathreshold level
- The response of bone to exercise is improved by brief but intermittent exercise
- Bone responds best when the exercise employs a pattern that differs from the usual loading pattern
- The response that any bone has to a mechanical stimulus such as exercise is proportional to the loading cycle
- For bone to adapt, it must have sufficient energy to rebuild itself
- For exercise to work there should be abundant calcium and vitamin d availability
- Bone adapts best to dynamic rather than static mechanical stimulation
The message that tells bone to grow in response to mechanical loading is most likely fluid flow through the __________ and around the ___________
The message that tells bone to grow in response to mechanical loading is most likely fluid flow through the canalicular channels and around the bone trabeculae
- Bone adapts best to dynamic rather than static mechanical stimulation
Hormonal responses promoting bone growth are amplified by _______ and by _____ in exercise patterning
Hormonal responses promoting bone growth are amplified by intensity and by differences in exercise patterning
What is a synonym for bone growth
osteogenesis
- If a bone is to respond to training, the stimulus must be at a suprathreshold level
Does High intensity RT = greater effects on bone density vs high impact aerobic training?
Are effects site specific?
What should the intensity be and how many reps?
- yes
- yes
- greater than 75% on 10 RM
- The response of bone to exercise is improved by brief but intermittent exercise
Dividing the total volume of work performed/week across 5 days has a greater __________ effect than doing the same volume of work in fewer days
Short intense exercise bouts build bone more __________ than longer sessions do. The goal is to reduce exercise time, it is better to shorten each exercise session than to reduce the number of sessions performed
Dividing the total volume of work performed/week across 5 days has a greater osteogenic effect than doing the same volume of work in fewer days
Short intense exercise bouts build bone more effectively than longer sessions do. The goal is to reduce exercise time, it is better to shorten each exercise session than to reduce the number of sessions performed
What are the goals, contraction and variations of the box drill
Goal: Balance training in ADL situations
Contractions: dynamic (concentric and eccentric)
Variations: directions in which the force is applied. you can control the intensity by changing the distance between the books, making them higher or lower, changing their size or weight
What are the goals, contraction, variation of the ladder drill
Goal: agility training
Contractions: Dynamic (concentric and eccentric)
Variations: Intensity (walking vs jumping and patterns of movement)
- The response that any bone has to a mechanical stimulus such as exercise is proportional to the loading cycle i.e how frequently the stimulus is applied
Is there a limit in the number of repetitions?
Based in the scientific literature, the number of loading cycles appears to have a positive effect up to approximately ______ cycles per day, after that adding more cycles has little or no additional effect
Yes there is a limit
40 cycles
As the number of cycles increases up to 40, there is a positive relationship btw # of cycles and bone density
- For bone to adapt, it must have sufficient energy to rebuild itself
Development of new bone = ______?
What are the 2 major dietary problems that OA may face?
-Development of bone = metabolic process requiring energy
- Low energy intake (especially low protein)
- Low calcium intake
What is the relationship between calcium and exercise on BMD in post-menopausal women?
There is only a positive change in BMD with the combination of exercise and Calcium
- For exercise to work there should be abundant calcium and vitamin d availability
What is the major role of calcium and vitamin d?
- Calcium: major raw material used to build bone, along with phosphate and magnesium. these raw materials need to be delivered from the digestive system to the building sites in the bones
- Vitamin D: Facilitates the absorption of calcium, phosphate and magnesium ions through the intestinal wall and into the blood stream
According to the ACSM guidelines for PRESERVING health in adult hood what is the mode, intensity, frequency and duration?
Mode: weight bearing endurance activities (jogging) activities that involve jumping and resistance exercise
Intensity: mod to high
Frequency: weight bearing endurance activities 3-5 times per week resistance training 2-3 times per week
Duration: 30-60 min of a combo of weight bearing endurance (jumping and resistance) that targets all major muscle groups
According to the ACSM guidelines for ELDERLY women and men DIAGNOSED w OSTEOPOROSIS what are the recommendations
- 1-3 sets with 5-8 reps of 4-6 weight bearing lower body strength exercises using BODY WEIGHT as resistance
- activities performed 2-3 days/week
- additional resistance may be applied gradually and conservatively with weighted vest
- Theraband and rubber tubing may be used to facilitate range of motion exercises
- avoid impact exercises, spinal flexion, extension, high compression and quick rotation
Are compression fractures likely to cause nerve or spinal cord damage in OA with osteoporosis? why?
For most fractures damages are limited to the front of the vertebral column so they are rarely associated with spinal cord damage
What is the leading cause of injuries among Canadians 65+
falls
Falls are the direct cause of ___% of all hip fractures leading to death in _____% of the cases
Falls are the direct cause of 95% of all hip fractures leading to death in 20% of the cases
Falls account for ____% of seniors injury related hospitalizations making this the _________ of injury related admissions for seniors. Falls are associated with over _______ of admissions to long-term care facilities after being released form the hospital
Falls account for 85% of seniors injury related hospitalizations making this the leading cause of injury related admissions for seniors. Falls are associated with over 1/3 of admissions to long-term care facilities after being released form the hospital
What is the direct cost of injury of seniors
2 billion
Where do injuries occur +/- half of all falls that lead to hospitalization in OA occur at home what are the 2 common areas
- Bathroom
2. Stairs
What is the viscous cycle that fear of falling can increase the risk of falls in OA
fall–>fear of falling–>reduced PA–> loss of muscle strength and mass–>increase risk of all
Age related changes in Sensory and Motor function cause OA to make more errors when they are required to move ______ than their ability to move _________
Age related changes in Sensory and Motor function cause OA to make more errors when they are required to move faster than their ability to move accurately
There is a continuous and progressive decrease in (3)
- nerve conduction velocity
- Proprioception at the foot and ankle
- Vestibular function (dizziness)
How much does nerve conduction velocity decrease by
10-15%
What are the 2 factors affecting the incidence of falls in OA
- impaired position sense
2. foot position awareness
What type of footwear maximizes proprioception
low heel and thin hard soles
What happens to visual acuity with age
decreases
What is the loss of vision mainly due to
anatomic changes in visual system (cornea, lense, iris, vitreous humor, visual cortex)
What are the 4 types of vision loss
- peripheral vision
- glare sensitivity
- dark adaptation
- depth perception
Interpretation of sounds depends on what 3 things
- acuity
- localization of sound
- ability to mask extraneous sound
Hearing impairment can be complicated by what 2 tings
- tinnitus (ringing)
2. speaking too fast
What are 4 functional implications of vision and hearing impairments
- exercise should be well lighted to compensate for vision impairments of OA
- Instructions should be spoken clearly and slowly
- Instructor should face participants and observe their comprehension
- For participants with a history of frequent falls or postural instability an external support can be useful
