Indirect Estimates of Jaw Muscle Tension in Children With Suspected Hypertonia, Children With Suspected Hypotonia, and Matched Controls PurposeIn this study, the authors compared indirect estimates of jaw-muscle tension in children with suspected muscle-tone abnormalities with age- and gender-matched controls.MethodJaw movement and muscle activation were measured in children (ages 3 years, 11 months, to 10 years) with suspected muscle-tone abnormalities (Down syndrome or spastic cerebral palsy; n = ... Article
Article  |   February 01, 2013
Indirect Estimates of Jaw Muscle Tension in Children With Suspected Hypertonia, Children With Suspected Hypotonia, and Matched Controls
 
Author Affiliations & Notes
  • Kathryn P. Connaghan
    University of Washington, Seattle
  • Christopher A. Moore
    University of Washington, Seattle
  • Correspondence to Kathryn P. Connaghan, who is now at Northeastern University, Boston, MA: kconnaghan.neu@gmail.comChristopher A. Moore is now at the Veterans Administration, Research Division, Rockville, MD.
  • Editor: Anne Smith
    Editor: Anne Smith×
  • Associate Editor: Steven Barlow
    Associate Editor: Steven Barlow×
Article Information
Speech, Voice & Prosodic Disorders / Dysarthria / Special Populations / Genetic & Congenital Disorders / Speech
Article   |   February 01, 2013
Indirect Estimates of Jaw Muscle Tension in Children With Suspected Hypertonia, Children With Suspected Hypotonia, and Matched Controls
Journal of Speech, Language, and Hearing Research, February 2013, Vol. 56, 123-136. doi:10.1044/1092-4388(2012/11-0161)
History: Received June 27, 2011 , Revised January 2, 2012 , Accepted May 20, 2012
 
Journal of Speech, Language, and Hearing Research, February 2013, Vol. 56, 123-136. doi:10.1044/1092-4388(2012/11-0161)
History: Received June 27, 2011; Revised January 2, 2012; Accepted May 20, 2012
Web of Science® Times Cited: 1

PurposeIn this study, the authors compared indirect estimates of jaw-muscle tension in children with suspected muscle-tone abnormalities with age- and gender-matched controls.

MethodJaw movement and muscle activation were measured in children (ages 3 years, 11 months, to 10 years) with suspected muscle-tone abnormalities (Down syndrome or spastic cerebral palsy; n = 10) and controls (n = 11). Two measures were used to infer jaw tension: a kinematic index of mass-normalized stiffness and electromechanical delay (EMD). The kinematic index used video-based kinematics to obtain the slope of the peak velocity-displacement relationship. The EMD was derived from the interval between the onset of suprahyoid muscle activity and the onset of jaw depression.

ResultsNeither measure differentiated the groups. The kinematic index revealed differences between stressed and unstressed syllables in 3-syllable productions by the participants with cerebral palsy and controls, but not in 2-syllable productions by the participants with Down syndrome and controls.

ConclusionThis preliminary investigation included the novel application of 2 measures to infer the jaw-muscle tension of children with suspected tone abnormalities. Although the results do not support the hypothesis that suspected muscle-tone abnormalities affect jaw movement sufficiently to influence speech production, considerations for interpreting the findings include methodological limitations and possible compensatory muscle coactivation.

Acknowledgments
Financial support for this research was received from National Institute on Deafness and Other Communication Disorders (NIDCD) Grant R01DC00822 and from the University of Washington Department of Speech and Hearing Sciences. Participant recruitment support was obtained through the Human Subjects Recruitment Research Core (NIDCD Grant P30 DC04661). We gratefully acknowledge the assistance of Roger Steeve, Lakshmi Ventakesh, Christiana Moor, and the members of the Developmental Speech Physiology Laboratory at the University of Washington for their assistance with data collection and analysis. Other assistance was provided by Thomas Campbell, Megan Hodge, Carol Stoel-Gammon, and Kathryn Yorkston. This investigation was conducted in partial fulfillment of the requirements of the first author’s doctoral degree at the University of Washington.
Order a Subscription
Pay Per View
Entire Journal of Speech, Language, and Hearing Research content & archive
24-hour access
This Article
24-hour access