ERIC Number: EJ1007668
Record Type: Journal
Publication Date: 2013-Feb
Abstractor: As Provided
Reference Count: 0
Indirect Estimates of Jaw Muscle Tension in Children with Suspected Hypertonia, Children with Suspected Hypotonia, and Matched Controls
Connaghan, Kathryn P.; Moore, Christopher A.
Journal of Speech, Language, and Hearing Research, v56 n1 p123-136 Feb 2013
Purpose: In this study, the authors compared indirect estimates of jaw-muscle tension in children with suspected muscle-tone abnormalities with age- and gender-matched controls. Method: Jaw 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. Results: Neither 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. Conclusion: This 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.
Descriptors: Human Body, Children, Neurological Impairments, Motor Reactions, Cerebral Palsy, Down Syndrome, Biomechanics, Syllables, Comparative Analysis, Measurement Techniques
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Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Authoring Institution: N/A