FOR IMMEDIATE RELEASE
February 4, 2009
Contact: Christine Guilfoy
Office: (301) 634-7253
cguilfoy@the-aps.org
Research Model May One Day “Inoculate”
Elderly Against Slip-Related Falls
BETHESDA, Md. (Feb 4, 2009)
− Training people to avoid falls by repeatedly exposing them to
unstable situations in the laboratory helped them to later maintain their
balance on a slippery floor, according to new research from the Journal
of Neurophysiology.
The study furthered the understanding of how the brain
develops fall prevention strategies that can be generalized to a variety of
conditions. The research could eventually help people, including the
elderly, for whom falling is an important health issue.
The study, “Generalization of gait adaptation for fall
prevention: from moveable platform to slippery floor,” is published
online by The American Physiological Society. Tanvi Bhatt and
Yi-Chung (Clive) Pai, of the University of Illinois at Chicago carried out
the study.
Will training transfer?
The researchers used a moveable platform which could be
operated to disrupt a person’s balance. Previous studies had shown that
people could quickly learn to maintain balance and avoid a fall with a short
training period on the platform. In this study, the researchers wanted to
see whether training on the platform could transfer to prevent a fall on a
slippery floor.
Dr. Pai, who teaches in the department of physical
therapy and whose work has been supported by National Institutes of Health,
National Institute on Aging, said he aims to train people to maintain
balance in the face of a situation that could cause a slip-related fall.
In the study, eight participants trained on the
moveable platform for a total of 37 times. The low-friction platform was set
up so that it released unannounced, 24 of those times. This release created
a low-friction condition to cause a frontward or backward slip. The platform
does not allow the foot to slip from side to side, as would be the case in a
real-life fall.
The participants wore a harness to record the amount of
assistance needed to catch them when they fell. Motion capture instruments
and videos of the sessions also helped to document slip outcomes
(“skate-over”, “walkover” or “loss of balance”) and falls.
The participants were compared to a group of seven
controls who did not receive any training on the platform. Both groups were
later asked to walk on a vinyl surface that had one slippery spot that they
could not see. Instruments and videos were used to record the extent of
their slip. The vinyl surface represented a particular challenge following
the laboratory training, in part because it could cause the foot to slide in
any direction.
Training inoculates against falls
The researchers found:
-
None of the trained participants fell on the slippery floor
and seven of the eight never lost balance.
-
The control group’s performance on the slippery floor
revealed their lack of training. Their performance was akin to the
trained group’s first training slip on the platform.
The trained subjects were able to transfer the skill
and avoid a fall on the slippery floor because they were better at
controlling the landing foot, that is, the foot that is on the ground during
the slip. They slowed down the movement of the foot as it began to slide
forward. The landing foot of people in the untrained group went out from
under them much faster.
“Controlling this foot, which is sliding forward, plays
an important role in maintaining stability and prevents a backward fall,”
Pai said. The researchers also found that the trained group unconsciously
changed their gait. They used a flatter landing foot and bent the landing
knee more. These changes reduced the landing force and the velocity of the
slip. Interestingly, the trained group did this while walking at their
customary speed.
May help elderly
The brain is able to generalize fall training from one
situation to another by modifying gait to make loss of balance less likely,
the authors concluded. These changes give the body greater stability when a
slip begins to occur. In addition, the study found that with one session of
such training, the brain pre-programs a response to slipping that can be
drawn upon quickly to stop a slip or a fall, or even to skate-over the
slippery surface without losing balance.
Fall training may be particularly helpful for active
elderly persons who put themselves in more challenging situations. Fall
prevention training may cut down on hip fractures, surgery, rehabilitation
and pain and suffering.
So far, the research team has used younger subjects
because the experiments carry some risk of injury. But in one study also
funded by National Institutes of Health, the researchers found that older
adults were able to learn as quickly as young adults. Further research is
now being conducted to find out if older adults can retain the training as
well as the young.
Pai and Bhatt’s research so far indicates that the
effects of one such training session, as with an inoculation, should last
for at least for four months, and perhaps much longer, to protect against
one of most dangerous falls, the backward falls.
NOTE TO THE MEDIA: To interview Dr. Pai, please
contact Christine Guilfoy at (301) 634-7253 or at
cguilfoy@the-aps.org.
***
Physiology
is the study of how molecules, cells, tissues and organs function to create
health or disease. The American Physiological Society (www.The-APS.org/press)
has been an integral part of this discovery process since it was established
in 1887.
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