Sports Medicine

, Volume 35, Issue 11, pp 935–950 | Cite as

A Nonlinear Dynamic Approach for Evaluating Postural Control

New Directions for the Management of Sport-Related Cerebral Concussion
  • James T. CavanaughEmail author
  • Kevin M. Guskiewicz
  • Nicholas Stergiou
Review Article


Recent research suggests that traditional biomechanical models of postural stability do not fully characterise the nonlinear properties of postural control. In sports medicine, this limitation is manifest in the postural steadiness assessment approach, which may not be sufficient for detecting the presence of subtle physiological change after injury. The limitation is especially relevant given that return-to-play decisions are being made based on assessment results. This update first reviews the theoretical foundation and limitations of the traditional postural stability paradigm. It then offers, using the clinical example of athletes recovering from cerebral concussion, an alternative theoretical proposition for measuring changes in postural control by applying a nonlinear dynamic measure known as ‘approximate entropy’. Approximate entropy shows promise as a valuable means of detecting previously unrecognised, subtle physiological changes after concussion. It is recommended as an important supplemental assessment tool for determining an athlete’s readiness to resume competitive activity.


Postural Control Postural Stability Postural Control System Quiet Standing Sensory Organisation Test 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



Dr Cavanaugh’s dissertation work focusing on the application of approximate entropy to the analysis of centre of pressure time series in athletes with concussion was conducted in the Sports Medicine Research Laboratory at the University of North Carolina, Chapel Hill, North Carolina, USA, under the direction of Dr Guskiewicz. The work was funded in part by grants from the Injury Prevention Research Center at the University of North Carolina at Chapel Hill, the National Center for Injury Prevention and Control (USA), the National Operating Committee on Standards in Athletic Equipment (USA), and the National Athletic Trainers’ Association Research and Education Fund (USA). The authors have no conflicts of interest that are directly relevant to the content of this review.


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Copyright information

© Adis Data Information BV 2005

Authors and Affiliations

  • James T. Cavanaugh
    • 1
    • 2
    Email author
  • Kevin M. Guskiewicz
    • 3
  • Nicholas Stergiou
    • 4
  1. 1.Geriatric Research, Education and Clinical Center, Department of Veterans Affairs Medical CenterDurhamUSA
  2. 2.Department of Physical and Occupational TherapyDuke University Medical CenterDurhamUSA
  3. 3.Department of Exercise and Sport ScienceUniversity of North CarolinaChapel HillUSA
  4. 4.HPER Biomechanics LaboratoryUniversity of Nebraska at OmahaOmahaUSA

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