Class 9 - Bone, Falls, and Resistance Flashcards
What are the two types of bone?
Compact and spongy
What are the three main factors that affect bone strength?
- Bone density
- Bone quality
- Bone geometry
What percent does bone density contribute to a bones resistance to a fracture?
50-80%
What is the estimated rate of bone loss after menopause?
1% and 2% for the first 10 years. Then it decreases 0.3-05% per year
What are the two major components that increase the structural integrity of bone?
Collagen & minerals
What are the 4 major bone minerals (in order of quantity)?
- Calcium
- Magnesium
- Sodium
- Potassium
T/F: for the same bone thickness, a bone with a smaller diameter is more resistant to a fracture.
False, larger diameter
What is the compensation for a loss of BMD called?
Periosteal Apposition
What is the criteria for osteopenia?
Lower than normal BMD (1-2.5 SD below normal)
What are the criteria for osteoporosis?
- Significant increase in fragility and susceptibility to fractures
- BMD more than or equal to 2.5 SD blow norm
What is the criteria for established osteoporosis?
Has osteoporosis and has had one or more fragility fractures
Most common areas for a fragility fracture?
Hip, spine, wrist
T/F: less than 1/3 of those who fracture their hips recover sufficiently to perform BADL and IADLs
True
What is the percent that women will experience a fracture in their lifetime
40%
What are the 7 principles for maximizing the influence of exercise on bone?
- Bone adapts best to dynamic rather than static mechanical stimulation
- For bone to respond, stimulus must be at a suprathreshold level
- Response is improved by brief but intermittent exercise
- Response is best when stimulus employs a pattern that differs from usual loading pattern
- Response is proportionate to loading cycle (frequency)
- Bone must have sufficient energy to rebuild
- Abundant vitamin d and calcium should be available
Where does the fluid flow in bone?
Canilicular channels and bone trabeculae
Which is better for bone density: high impact or high intensity?
High intensity
What should the intensity be for improving BMD?
Greater than 75% of 10 RM
T/F: similar volume but more frequent exercise bouts are more effective?
True, greater osteogenic effect
What are the main variables of RT programming?
- The amount of resistance
- The methodof resistance used
- The directions of the force applied
What is the limit of loading cycles per day for positive effects?
40, after that little effect
What are two major dietary problems that OA face?
Low energy intake (low protein) and low calcium intake
Vitamin D facilitates the absorption of what?
Calcium, phosphate, magnesium
What are the exercise recommendations for OA with diagnosed osteoporosis?
1-3 sets with 5-8 reps of 4-6 WB exercises using body weight.
2 to 3 days per week
What exercises should be avoided with OA with osteoporosis? (5)
- Impact
- Spinal flexion against resistance
- Spinal extension
- High compressive forces on spine
- Quick trunk rotation
What is the leading cause of injuries in Canadians 65+ ?
Falls
What percent of Canadian dwelling seniors experience one fall per year?
20-30%
Research suggests that falls are the direct cause of __ % of all hip fx. Leads to death in __% of cases.
95%, 20%
Falls account for __% of OA injury related hospitalizations.
85%
About half of all falls leading to hospitalization occur in the house. Where are the two most common sites?
Bathroom, stairs
What is the fear of falling cycle?
- Fall
- Fear of falling
- Reduced physical activity
- Loss of muscle mass and strength
What continuous and progressive declines in OAs contribute to falls? (3)
- Decreased nerve conduction velocity (10-15%)
- Decreased proprioception (Decreased response of muscle spindles)
- Poor vestibular function (dizziness)
What two factors affect the incidence of falls?
- Impaired position sense
- Foot position awareness
What 4 factors of vision loss occur in OA?
- Peripheral vision
- Glare sensitivity
- Dark adaptation
- Depth perception
What 3 audible factors decline with age?
- Acuity
- Localization of sound
- Ability to mask extraneous sound
What accommodations can be made for OA with sensory issues? (4)
- Well lit exercise area (unless done on purpose for a challenge)
- Instructions spoke clearly and slowly
- Instructor should face participants and observe their comprehension
- External support can be given during exercise (chair, wall. Etc)
