Face-referenced measurement of perioral stiffness and speech kinematics in parkinson’s disease

Shin Ying Chu, Steven M. Barlow, Jaehoon Lee

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


Purpose: Perioral biomechanics, labial kinematics, and associated electromyographic signals were sampled and characterized in individuals with Parkinson’s disease (PD) as a function of medication state. Method: Passive perioral stiffness was sampled using the OroSTIFF system in 10 individuals with PD in a medication ON and a medication OFF state and compared to 10 matched controls. Perioral stiffness, derived as the quotient of resultant force and interoral angle span, was modeled with regression techniques. Labial movement amplitudes and integrated electromyograms from select lip muscles were evaluated during syllable production using a 4-D computerized motion capture system. Results: Multilevel regression modeling showed greater perioral stiffness in patients with PD, consistent with the clinical correlate of rigidity. In the medication-OFF state, individuals with PD manifested greater integrated electromyogram levels for the orbicularis oris inferior compared to controls, which increased further after consumption of levodopa. Conclusions: This study illustrates the application of biomechanical, electrophysiological, and kinematic methods to better understand the pathophysiology of speech motor control in PD.

Original languageEnglish (US)
Pages (from-to)201-212
Number of pages12
JournalJournal of Speech, Language, and Hearing Research
Issue number2
StatePublished - Apr 1 2015

ASJC Scopus subject areas

  • Language and Linguistics
  • Linguistics and Language
  • Speech and Hearing


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