Effect of an Oral Motor Exerciser in Articulation Therapy: A Single Subject Design

University of Minnesota-Duluth
Department of Communicative Sciences and Disorders
Amy E. Skinder-Meredith
229 Bohannon Hall, 1207 Ordean Ct.
Duluth, MN 55812

Abstract:

This single-subject pilot study was conducted to investigate the effectiveness of an oral motor exerciser (Iso-flex) using an A-B-A design. A seven-year, eleven-month-old female with persistent /r/ and /s/ articulation errors and tongue thrust served as the subject. The child participated in speech therapy for 16 sessions over eight weeks. The pre-vocalic and vocalic /r/ were treated with traditional articulation drill therapy (TADT) throughout the course of treatment, while /s/ received only the oral motor exercise (Iso-flex) treatment, which was introduced during the third session and withdrawn following the twelfth session. Probe data was taken on all sounds in words and sentences at the end of each session to monitor progress with and without the Iso-flex.

Data trends were analyzed using visual analysis and an Ordinary Least Squares Regression with a time indicator. Visual analysis of the pre-vocalic and vocalic /r/ probe data did not show a clear effect from implementation of the Iso-flex, but the regression analysis showed the device had a significant effect on accuracy of /r/ when used with TADT. There was no significant effect regarding accuracy of /s/.

Introduction:

The purpose of this single subject pilot study was to test the effectiveness of an oral-motor device (Iso-flex) when used with and without traditional articulation therapy (TADT) in the treatment of a child with a phonologic/articulation disorder (PAD). The use of oral motor exercises in the treatment of speech disorders has been the subject of much controversy (Clark, 2003; Forrest, 2002; Hodge, 2002). Although there are many oral-motor devices on the market, there is little research to show they are efficacious (Christenson & Hanson, 1981; Fields & Polmanteer, 2002; Ray, 2003). Furthermore, there is substantial research on speech physiology, strengthening, and motor learning principles that counter-indicate, or question the use of non-speech oral exercises for improving articulatory performance (Campbell, Barlow, & Moore, 2000; Clark, 2003; Forrest, 2002; Hodge, 2002).

Several studies have examined the efficacy of oral-myofunctional therapy for tongue thrust and correction of distorted /s/ (Christenson & Hanson, 1981; Gommerman & Hodge, 1995; Overstake, as cited in Forrest, 2002). Interestingly, one study showed motor speech tasks generalized to improved accuracy of speech (Overstake, as cited in Forrest, 2002), yet others found only the task trained improved (Christenson & Hanson, 1981; Gommerman & Hodge, 1995). Fields and Polmanteer (2002) examined the effects of oral motor therapy in addition to TADT versus TADT alone. They found the group that received both types of therapy had fewer articulation errors following the study, when compared to the group who only received TADT.

Results such as these (above) suggest further investigation into the use of oral motor exercises is warranted. Unfortunately, there is a lack of foundation-based information needed to judge the theoretical soundness of these types of treatment strategies (Clark, 2003). For example, the rationale for targeting strength of an articulator to improve articulation is wrought with controversy. As Forrest (2002) pointed out, the use of oral-motor exercise to increase articulator strength needs to be questioned since we do not have evidence that children with PADs have a deficit in strength. Furthermore, data suggested that only 10% to 20% of the maximum force of lip movement; 20% of maximum force of tongue strength; and 11% to 15% of jaw strength is needed for speech (Forrest, 2002; Loff, 2004; Love, 2000).