Modulation of anticipatory postural adjustments using a powered ankle orthosis in people with Parkinson's disease and freezing of gait

Matthew N. Petrucci, Colum D. MacKinnon, Elizabeth T. Hsiao-Wecksler

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

Background: Freezing of gait (FOG) during gait initiation in people with Parkinson's disease (PD) may be related to a diminished ability to generate anticipatory postural adjustments (APAs). Externally applied perturbations that mimic the desired motion of the body during an APA have been demonstrated to shorten and amplify APAs; however, no portable device has been tested. In this study, a portable powered ankle-foot orthosis (PPAFO) testbed was utilized to investigate the effect of mechanical assistance, provided at the ankle joint, on the APAs during gait initiation. Research question: Does mechanical assistance provided at the ankle joint improve APAs during gait initiation in people with PD and FOG? Methods: Thirteen participants with PD and FOG initiated gait across five test conditions: two self-initiated (uncued) conditions in walking shoes [Baseline-Shoes], and the PPAFO in unpowered passive mode [Baseline-PPAFOPassive]; three “go” cued conditions that included an acoustic tone with the PPAFO in unpowered passive mode [Acoustic + PPAFOPassive], the mechanical assistance from the PPAFO [PPAFOActive], and the acoustic tone paired with mechanical assistance [Acoustic + PPAFOActive]. A warning-cue preceded the imperative “go” cue for all the cued trials. Peak amplitudes and timings of the vertical ground reaction forces (GRFs) and center of pressure (COP) shifts from onset to toe-off were compared across conditions. Results: Mechanical assistance significantly increased the peak amplitudes of the GRFs and COP shifts, reduced APA variability, and decreased the time to toe-off relative to the passive conditions. Significance: These findings demonstrate the potential utility of mechanical assistance at the ankle joint (with or without an acoustic cue) as a method to generate more consistent, shortened, and amplified APAs in people with PD and FOG.

Original languageEnglish (US)
Pages (from-to)188-194
Number of pages7
JournalGait and Posture
Volume72
DOIs
StatePublished - Jul 2019

Bibliographical note

Funding Information:
This material is based upon work supported by the NSF under Grant No. 0903622 and partial funding from the Center of Compact and Efficient Fluid Power (CCEFP) Grant No: 0540834, NIH grant RO1 NS070264, and the University of Illinois at Urbana-Champaign Dissertation Travel Grant. The authors would like to thank the participants of the study and members of the Human Dynamics and Controls Lab and Movement Disorders Lab.

Funding Information:
This material is based upon work supported by the NSF under Grant No. 0903622 and partial funding from the Center of Compact and Efficient Fluid Power (CCEFP) Grant No: 0540834 , NIH grant RO1 NS070264 , and the University of Illinois at Urbana-Champaign Dissertation Travel Grant . The authors would like to thank the participants of the study and members of the Human Dynamics and Controls Lab and Movement Disorders Lab.

Publisher Copyright:
© 2019 Elsevier B.V.

Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.

Keywords

  • Anticipatory postural adjustments
  • Freezing of gait
  • Gait initiation
  • Parkinson's disease
  • Powered orthosis
  • Sensory cueing

Fingerprint Dive into the research topics of 'Modulation of anticipatory postural adjustments using a powered ankle orthosis in people with Parkinson's disease and freezing of gait'. Together they form a unique fingerprint.

Cite this