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Magnusson M. (1), Pope M. (2) and Wilder D. (2)
(1) Dept. of Orthopædics, Occupational Unit, Sahlgren
University Hospital, S-413 45 Göteborg, Sweden
(2) Iowa Spine Research Center, The University of Iowa, Iowa
City, IA
Introduction: A review of a number of studies involving low
back pain led to the statement that "asymmetric muscle contraction
can lead to unequal stress concentrations on the different components
of the spine with increased risk of injury." It is possible
that industrial back supports have an effect of decreasing overall
motion or changing motion from one direction to another.
The purpose of this study then was to record motion during
a lifting task performed with and without an industrial back
support.
Discussion: In most cases the lumbar support affected the
way the subject lifted the load. In all but one subject the motion
in all directions was significantly different when a back support
was worn. In most cases the flexion was reduced with a back support
but there was no consistent pattern of change in other directions.
It is probable that a back support, when worn properly low
over the hips, affects the way an individual lifts by providing
stimulus/response feedback. Clearly, forward flexion was reduced
suggesting that the legs were used more in the lifts. Coupled
with instruction, it would appear that back supports can reduce
loads in the spine and thus may have positive effect on rapidly
rising costs due to low back pain.
Conclusion: It appears that a back support does affect the
way a lift is conducted. If the worker is encouraged to lift
in a sagittal plane, then the flexion and thus the load moment
will be decreased if a back support is worn.
"Clearly forward flexion was reduced suggesting
that the legs were used more in the lifts. Coupled with instruction,
it would appear that back supports can reduce loads in the spine
and thus may have a positive effect on the rapidly rising costs
due to low back pain. "
David G. Wilder, PhD
Accepted for presentation at the Spine Society annual meeting,
June 1996, Burlington, VT. (Review by Chase Ergonomics approved
by Dr. Magnusson, July 1996.)
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