Vibration therapy lacks cardiovascular benefit of exercise
for senior citizens, but it can improve muscle strength and weight loss
- See video in story on how it works
Oct. 25, 2010 -
A daily dose of whole body vibration may help reduce the usual bone
density loss that occurs with age, Medical College of Georgia
researchers report. The study supports the growing use of this technique
by trainers and rehab specialists.
Twelve weeks of
daily, 30-minute sessions in 18-month old male mice which equate to
55- to 65-year-old humans appear to forestall the expected annual loss
that can result in fractures, disability and death.
Dr. Karl H. Wenger,
biomedical engineer in the MCG Schools of Graduate Studies and Medicine,
reported the findings with his colleagues in the journal Bone.
Researchers
found vibration improved density around the hip joint with a shift
toward higher density in the femur, the long bone of the leg, as well.
Hip fractures are a major cause of disability and death among the
elderly.
They also found
a reduction in a biomarker that indicates bone breakdown and an increase
in the surface area involved in bone formation in the vibrating group.
Dr.
Karl H. Wenger is a biomedical engineer in the MCG Schools
of Graduate Studies and Medicine.
Phil Jones, Campus
Photographer
The findings
provide more scientific evidence that the technique, which dates back to
the 1800s and is now showing up in homes, gyms and rehabilitation
clinics, has bone benefit, particularly as a low-risk option for injured
individuals with limited mobility, Wenger said.
The scientists
theorize that the rhythmic movement, which produces a sensation similar
to that of a vibrating cell phone but on a larger scale, exercises cells
so they work better. Vibration prompts movement of the cell nucleus,
which is suspended by numerous threadlike fibers called filaments.
"The filaments
get all deformed like springs and then they spring back," Wenger said.
All the movement
releases transcription factors that spur new osteoblasts, the cells that
make bone. With age, the balance of bone production and destruction by
osteoclasts tips to the loss side.
In the case of
an injury, vibration acts on stem cells, the master controllers of the
healing process.
"We think that in fracture healing, you get a more
dramatic response. We don't know exactly why it affects the biology
differently but it's likely because of the extent to which stem cells
invade the injured area," Wenger said.
Watch video explaining how
vibration training and therapy work.
They have found
that vibration slows stem cell proliferation, which may sound
counterintuitive, but likely means more stem cells differentiate into
bone cells rather than continuing to just make more generic stem cells.
With age, stem cells have difficulty differentiating.
To see if their
findings translate to the trauma clinic, they are evaluating vibration
tolerance in patients with lower-limb fractures and finding,
surprisingly, that even two weeks after injury the subtle vibration is
soothing, rather than painful, to most.
The bone group,
based in the MCG Department of Orthopaedic Surgery, also is working with
Georgia Prevention Institute scientists to explore vibration's potential
to improve glucose uptake to see if vibration results in more insulin
production or aids glucose clearance in some other way and whether,
like exercise, it can reduce fatty liver disease in chunky, pre-diabetic
children.
Postmenopausal
women
In related
studies, postmenopausal women at the peak age of bone decline,
experienced results similar to those of Wenger's aging mice. Wenger's
studies used only male mice to mitigate the impact of fluctuating
hormones and focus on aging. In the human study, led by Dr. Clinton T.
Rubin at the State University of New York at Stony Brook, the women
receiving daily whole body vibration didn't gain appreciable bone but
they did not lose it either.
While vibration
lacks the same cardiovascular benefit of exercise, animal and human
studies also have shown it can improve muscle strength and weight loss.
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