Journal article Open Access
Introduction: Prolonged sitting is often proposed as a risk factor for low back pain development. The purpose of
this study was to evaluate the acute effect of full time office work on sensorimotor trunk functions.
Methods: Seventeen healthy office workers participated in the study. Maximal lumbar flexion range of motion,
anticipatory postural adjustments and postural reflex reactions were tested before and after full time office work
in a real life environment.
Results: There were longer onset latencies of postural reflexive reactions and decreased response amplitudes of
anticipatory postural adjustments after full time office work, but these were significant only for the obliquus
externus abdominis muscle. No changes in lumbar range of motion was found.
Conclusion: To our knowledge this is the first study that evaluates the effect of full time office work on postural
actions and lumbar RoM. We found an absence of normal human circadian flexibility in the lumbar spine and
some changes in postural actions. We propose that active trunk stiffness increase to compensate for decreased
passive stiffness after prolonged seated work. Further studies are needed to confirm this assumption.