Is postural control during unstable sitting a proxy measure for determinants associated with lumbar stability?

Christian Larivière*, Richard Preuss, Daniel Ludvig, Sharon M. Henry

*Corresponding author for this work

Research output: Contribution to journalArticle

Abstract

The aim of this study was to test whether determinants associated with lumbar stability can predict performance during unstable sitting (trunk postural control - TPC). If confirmed, unstable sitting could be viewed as a proxy measure for these determinants. Wobbling chair motion was measured in 58 subjects with an inertial sensor, and six outcomes were computed (mean frequency and velocity, frequency dispersion, two variables from the sway density analysis and Lyapunov exponent - short interval) to represent TPC performance. Subjects also performed five other trunk neuromuscular tests to quantify the thickness of back and abdominal muscles and connective tissues, lumbar proprioception, lumbar stiffness, feedforward and feedback control mechanisms, and trunk/muscle coordination. Four to five predictors explained between 36 and 47% of TPC outcomes variance, as determined with multivariate analyses. These predictors were mainly related to (1) angular kinematic parameters of the pelvis or lumbar spine following rapid arm movement, (2) lumbar intrinsic stiffness, (3) thickness of perimuscular connective tissues surrounding specific abdominal muscles, (4) activation onsets of specific trunk muscles (IO/TrA and iliocostalis lumborum) before rapid arm movement, and (5) percent thickness change of internal oblique (IO) and transversus abdominis (TrA) muscles. Lumbar proprioception and reflex responses were not predictive, possibly due to the lack of appropriate measurements. These findings support the use of TPC in unstable sitting as a proxy measure for determinants associated with lumbar stability. This might be useful in research and clinical settings, considering time and equipment constraints associated with measuring these determinants individually.

Original languageEnglish (US)
Article number109581
JournalJournal of Biomechanics
Volume102
DOIs
StatePublished - Mar 26 2020

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Keywords

  • Anticipatory postural adjustments
  • Low back pain
  • Lumbar stiffness
  • Proprioception
  • Trunk coordination

ASJC Scopus subject areas

  • Biophysics
  • Orthopedics and Sports Medicine
  • Biomedical Engineering
  • Rehabilitation

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