EMG activity of orbicularis oris superior, orbicularis oris inferior, and masseter muscles of mild and moderate articulatory disordered children.

The peak amplitude of EMG activity was measured from the orbicularis oris superior, orbicularis oris inferior, and masseter muscles for 3 mild and 3 moderately articulatory disordered and 3 normal children. The three groups showed similar levels of average peak EMG activity and variance across the three muscles, suggesting that the disordered children were free to vary their patterns of activity for these muscles when repeating a series of syllable tokens.