EMG Activity with the Jaw Fixed of Orbicularis Oris Superior, Orbicularis Oris Inferior and Masseter Muscles of Mild and Moderate Articulatory Disordered Children

Abstract

The peak amplitude of EMG activity was measured from the orbicularis oris superior, orbicularis oris inferior, and masseter muscles of 3 mild and 3 moderately articulatory disordered and 3 normal boys repeating a series of /p æ/ syllable trains with the jaw fixed. Analysis showed similar levels of peak EMG amplitude and variability of performance for all subjects across the three muscles. These data were interpreted to suggest that speech-motor equivalence for simple articulatory acts requiring compensation is functioning within normal limits for the disordered subjects studied here.