"Osteoporosis"
Osteoporosis is the most common metabolic bone disease
in adults. (Hertling, 1990). It is characterized by a low
bone mass and loss of bone strength, which leads to fragile
and brittle bones and a high risk to fracture. Although
this loss of bone in itself does not normally cause symptoms,
the associated fracture and collapse of vertebrae can be
extremely painful and limiting. Each year, osteoporosis
leads to 1.5 million fractures in the U.S. That means that
someone suffers a hip fracture approximately every 2 minutes.
(Chrischilles et al, 1994). 1 in 3 Americans over the age
of 50 (mainly women) will suffer a fracture related to
low bone mass. (Cooper et al, 1992). According to the National
Osteoporosis foundation, the associated cost of osteoporotic
fracture is approximately $10 billion per year.
Our bones are constantly going through a remodeling cycle.
Cells called osteoblasts are building up or forming new
bone, along with osteoclasts, which lead the process of
bone resorption (bone removal). When we are kids and teenagers
the rate of bone formation is faster than bone resorption,
this leads to an overall gain in bone mineral. As we reach
adulthood, this process of resorption occurs at a faster
rate than new bone can form. This causes a steady gradual
decline in the density of our bones of about 1% per year.
(Witzke, 99). This rate can be as high as 3-5% in postmenopausal
women. Osteoporosis occurs 9 times more frequently in women
than in men.
The three most common sites for fracture
with osteoporosis are the spine (vertebral fractures,
hip and wrist. Most fractures are the result of a fall,
but in the case of a vertebral fracture, it may be something
as simple as turning over in bed. The most debilitating
of all osteoporotic fractures, is the hip. Which can
lead to a loss in independence and even death from surgery
or prolonged bed rest. “It
is estimated that 50 % of people who sustain a hip fracture
due to a fall never become functional walkers again.” (Witzke,
99).
While the exact causes of osteoporosis are not understood,
there are factors that can help you determine your potential
risk.
1. Genetics: These are things you can’t control,
such as: family history, fair complexion, Northern European
or Asian descent, small thin frame.
2. Estrogen: This hormone helps to slow the rate of bone
resorption. Estrogen deficiency is most commonly seen in
postmenopausal women and young, athletic amenorrheic women.
Amenorrhea is the loss of a menstrual cycle due to excessive
exercise & physical training. Studies have shown that
young amenorrheic but otherwise healthy aerobic instructors,
have been shown to have the bone density equal to that
of a 50 year old women. (Drinkwater et al, 1994). This
loss in bone mass has been shown to be irreversible in
young women who have gone without their menstrual cycle
for as little as 12 months. This puts them at a much higher
risk of osteoporosis.
3. Dietary Calcium intake: Calcium is essential for proper
bone formation. If you are not getting enough calcium from
your diet, then the calcium is pulled from your bones in
order to maintain the proper blood levels.
4. Lifestyle factors: All tissues in the body atrophy when
they are not used and bone is no exception. The pressure
of weight bearing and the stress through our bones from
the pull of the muscles actually stimulate new bone formation.
(Salter, 1983). If someone is confined to a bed or severely
limited in their activities, their bone formation capabilities
slow and can’t keep up with the bone resorption rate.
This leads to disuse atrophy. The only way to actually
increase new bone formation (after maturity) is through
skeletal loading.
According to the American College
of Sports Medicine, which published a Position Stand on
Osteoporosis in 1995, they determined that:
- Weight bearing
physical activity is essential for the normal development
and maintenance of a healthy skeleton. Activities that
focus on increasing muscle strength also may be beneficial,
particularly for non-weight bearing bones.
- Sedentary
women may increase bone mass slightly by becoming more
active, but the primary benefit of the increased activity
may be in avoiding the further loss of bone that occurs
with inactivity.
- Exercise cannot be recommended as a
substitute for hormone-replacement therapy at the time
of menopause.
- The optimal program for older women includes
activities that improve strength, flexibility and coordination
that may indirectly, but effectively, decrease the
incidence of osteoporotic fractures by lessening the
likeliness of falling. (Whitzky, 1999. ACSM, 1995)
So, in conclusion, there is something
that we can do to keep our bones from getting more fragile
and reduce the risk of osteoporosis and fractures. Stress
our bones…Forceful
muscular contractions…Direct impact activities…Jumping…Weight
lifting. These activities put force or stress through the
bone. Activities such as walking or swimming may be good
for balance, endurance and cardiovascular conditioning,
they do not sufficiently overload the bone in order to
increase bone formation or slow bone loss.
If you suffer
from osteoporosis, or are unsure how to safely get started
on an exercise program, you may want to see a physical
therapist. After you have been given clearance from your
doctor, a physical therapist can evaluate your specific
needs and start you on an individualized program. Remember,
it’s never too
late to make a difference.
Bibliography
1. Whitzky, K. (1999). Osteoporosis. Clinical Exercise
Specialist Manual. P360-377. San Diego, Calif.
2. Salter, R. (1983). Textbook of Disorders
and Injuries of the Musculoskeletal System. Williams & Wilkins.
Baltimore.
3. Hertling & Kessler. (1990).
Management of Common Musculoskeletal Disorders. JB Lippincott.
Philadelphia.
5. American College of Sports Medicine. (1995). ACSM position
stand on osteoporosis and exercise. Medicine and Science
in Sports and Exercise, 27, 4, I-vii.
6. Chrischilles, Sherman & Wallace. (1994). Cost and
Health Effects of Osteoporotic Fractures. Bone, 15, 377-386.
7. Drinkwater, Nilson & Chesnut. (1994). Bone Mineral
Content of Amenorrhea and Eumenorrheic Athletes. New England
Journal of Medicine, 311, 277-281.
8. Cooper, Campion & Melton. (1992). Hip Fractures
in the Elderly; A Worldwide Projection. Osteoporosis International,
2, 285-289.
