Vol. 16 Issue 48
Muscle-based approach to speech therapy
Speech clarity concerns unexplained by traditional articulation and phonological parameters present unique diagnostic and therapeutic questions for speech-language pathologists. When articulation and phonological interventions do not adequately help those with speech clarity disorders, many clinicians are unsure where to turn. Non-traditional speech disorders commonly have muscle weakness/instability as a core foundation.
Underlying muscle weakness and instability of the jaw, lips and tongue can lead to poor muscle coordination for speech.1 When the foundations of speech are compromised, due to various deficits and disorders affecting muscle movement, speech clarity is diminished. A muscle-based approach to speech therapy provides the basic building blocks of speech by addressing speech clarity disorders secondary to muscle weakness, tone or sensory deficits, and/or motor planning problems.
Sara Rosenfeld-Johnson, MS, CCC-SLP, has developed a hierarchical model of muscle-based techniques based on her training in neurodevelopmental techniques2 to address inherent muscle weakness and incoordination. Such techniques provide an interdisciplinary approach to the management of various muscle-based disorders. These techniques are built upon methods used by occupational therapists, physical therapists and speech-language pathologists alike. A more holistic approach to therapeutic intervention can provide the experience of normal movement.
This muscle-based approach provides a stable basis for later developing speech sounds in clients with various forms of dysarthria. It is a common misconception that oral-motor, muscle-based therapies are recommended for and applied directly to populations not displaying muscle deficits, such as those with traditional articulation and phonological disorders of speech.3,4 Populations who can and do benefit from oral-motor, muscle-based interventions are those who benefit from multimodal and multisensory approaches and those with inherent muscle or movement deficits for respiration, body posture stability, or weakness and/or incoordination of the velum, jaw, lips and tongue. Clients seen at Rosenfeld-Johnson's clinic in Tucson, AZ, are evaluated based on these premises and only treated if muscle or movement deficits are observed and described. (See Figure 1.)
Muscle-based therapies provide a stable foundation for speech by first addressing instability in the jaw, lips and tongue in the same way physical therapists work on normalizing muscle skills in crawling before muscle skills required for walking. The muscle-based techniques developed by Rosenfeld-Johnson are multisensory and multi-modal.
According to Raquel de Benabib, MS, COVT, and Christine Nelson, PhD, OTR, NDT, "More sensory nerve fibers are present in the mouth than in any other part of the human body, and evolution of mouth function supports organization of the entire body."5
Therefore, motor skills in feeding and non-speech movements act as prerequisites to speech clarity. Feeding and non-speech activities are targeted prior to speech production tasks to ensure adequate muscle functioning is available.
All of these areas of intervention can be targeted during a single session. For example, if a child is demonstrating difficulty achieving lip closure, muscle movements of the lips and jaw are targeted until the child is able to obtain closure (e.g., working toward complete lip closure on a tongue depressor). Once closure is achieved during the therapy session, the child immediately is shown how to make an /m/ sound for word approximations such as "more," "mom," etc. It is important to emphasize that oral-motor, muscle-based techniques are used in conjunction with speech therapies (traditional and otherwise) to facilitate speech at all times, with the muscle-based practices providing a stable foundation for more successful speech therapy.
Muscle-based non-speech activities are facilitated through exercises that stimulate the required movements for speech. Therapy tools that normalize muscle movements for the development of standard speech clarity have been developed to achieve these movements. These tools are designed to be fun to use and familiar in nature: bubbles, horns, silly straws, flavored tongue depressors, etc.
The tools used in any step-by-step, task-analyzed exercise will increase in difficulty in small increments, resulting in improved muscle skills through increased resistance. These tools also encourage children, adolescents and adults alike to participate and work at their highest level before failure toward the goal of normalizing muscle skills for speech.
Speech therapy in this model, as in physical and occupational therapy, allows clients to experience success before frustration. Those with physiological deficits and their caregivers often become frustrated when demands upon speech mechanisms are higher than a client's level of ability, as seen when more traditional speech therapies are applied to oral muscular systems that cannot accommodate the mechanics of speech.
By following the normal development of muscle physiology and speech development, muscle-based therapies can be highly effective for populations displaying underlying muscle deficits. Muscle-based therapy techniques address normal development of oral movement in a hierarchical sequence (i.e., respiration, phonation, resonation and articulation). Once the desired movement is obtained reliably in a non-speech context, the movement is immediately transitioned to speech production tasks. Exercise physiology techniques are used to prepare oral muscles for this transition by building stamina and control.
For example, clients who persist in a forward lingual movement at rest, during speech, and on the swallow past acceptable developmental timelines are taught to use a more retracted lingual movement while straw drinking. Muscle-based therapy continues this developmental sequence through developing tongue lateralization inside the mouth, followed by tongue elevation as a precursor to the elevation required for speech sound production. By following this developmental hierarchy, muscle-based interventions can facilitate speech articulation from the perspective of the normal sequence of muscle development.
However, tongue retraction and stabilization are but a small portion of how the muscles of speech function for speech clarity. Rosenfeld-Johnson developed a hierarchical muscle-based approach to speech clarity involving all of the movement systems of speech. Each hierarchy is based on two principles of muscle physiology: dissociation and grading.
Dissociation is the separation of movement, based on stability and strength, in one or more muscle groups. Grading is the controlled segmentation of movement through space based on dissociation. Dissociation and grading of the jaw, lips and tongue are necessary for the functional movements of speech.6
This hierarchical model of implementation requires adequate strength and stability in the jaw to support dissociated and graded movements. This in turn allows for further movement of the lips and tongue in conjunction with, and separate from, the jaw itself. (See Figure 2.)
A hierarchical model requires movement against resistance in much the same way physical therapists and occupational therapists use movement to improve function. The jaw acts as the foundation of all other movements of speech. Once the jaw is stable, graded movement of the lips and tongue can be targeted and more readily achieved.
During this transition, facilitation of speech and language continues through principles of modeling and co-occurring related therapy services. Rosenfeld-Johnson's muscle-based techniques are used to improve and normalize tone, strength and coordination of muscle movements required for respiration, phonation, resonation and articulation.
Improvements in dysarthria and overall low-tone require a change in muscle responses through sensory and movement activities. Multisensory and multimodal activities can stimulate the muscles, along with the neuropathways of coordinated muscle movements of speech, to improve functionality for speech.7
With ongoing treatment and practice throughout the day–as in a parent- or school-based program–muscles with low tone can become stronger and more efficient. Improvement in tone, strength and coordination also relies on a hierarchical model of muscle specificity.
Muscle physiologists look at muscle specificity to determine how specific muscles function based on their intended movements. Strength and endurance subsequently are targeted as therapeutic goals to achieving desired muscle movements.8
The principles of muscle specificity have been applied to speech and oral-motor therapies in general to determine how to improve strength, tone, endurance and coordination for accurate speech production. By isolating specific muscle function, specific speech sound errors can be targeted and improved through a muscle-based approach.
Cautions against more traditional oral-motor therapy techniques usually center on techniques involving movements not used during speech, such as tongue wagging and lip licking, noting that these exercises require tongue protrusion, which never occurs during speech production.4,9,10
Techniques such as these are not practiced as part of Rosenfeld-Johnson's muscle-based therapies. Instead, her therapies target underlying movements of the articulators, such as jaw stability, lip rounding, tongue elevation and lateralization, and respiratory support to facilitate conversational speech.
The speech-like movements provide a stable foundation for accurate speech production. Once muscle stabilization and coordination are achieved, exercise is phased out to accommodate more traditional speech therapy techniques. When children are able to move their articulators appropriately for various speech sounds, such as tongue tip elevation required for /t/ and /d/, speech intervention is more successful and appropriate.
The muscle-based techniques developed by Rosenfeld-Johnson are multisensory and multimodal, and the hierarchical activities can be used with clients who present with speech clarity disorders as a result of poor muscle control. Therefore, various therapeutic speech techniques are used, depending on each child's individual needs.
Some clients require more sensory input, such as touch, to enable them to interpret and repeat specific speech sounds. Other clients do very well with picture stimuli, while still others can imitate speech sounds through verbal imitation.
Multisensory and multimodal techniques allow therapists to assess and treat each client based on his or her needs according to the presenting symptoms and observable behaviors. By addressing a client's sensory, feeding, behavioral, speech, language and overall communication needs, therapists can better treat each person as a whole to determine what works.
1. Rosenfeld-Johnson, S. (2001). Oral-Motor Exercises for Speech Clarity: A Comprehensive, Step-by-Step Guide That Fills the Gap Between What We Were Taught and What We Need to Know. ITI and Sara Rosenfeld-Johnson.
2. Bobath, K. (1971). Motor development, its effect on general development, and application to the treatment of cerebral palsy. Physiotherapy, 57 (11): 526-32.
3. Clark, H.M. (2003). Neuromuscular treatments for speech and swallowing. American Journal of Speech Language Pathology, 12: 400-15.
4. Forest, K. (2002). Are oral motor exercises useful in the treatment of phonological/articulatory disorders? Seminars in Speech and Language, 23 (1), 15-25.
5. Nelson, C.A., De Benabib, R.M. (1991). Sensory preparation of the oral-motor area. In B. Langley & L.J. Lombadino (eds.), Neurodevelopmental Strategies for Managing Communication Disorders in Children with Severe Motor Dysfunction. Austin, TX: Pro-Ed.
6. Bahr, D.C. (2001). Oral Motor Assessment and Treatment: Ages and Stages. Needham Heights, MA: Allyn & Bacon.
7. Gagnon, D.E. (1999). Medical information: Tone versus strength. Accessed online at http://www.freespace.virgin.net/bch.hypotonia/tonevstrength.htm.
8. Hibberd, J., Jinks, C. (1998). Muscle specificity: Strength, endurance and functional improvement. Speech and Language Therapy in Practice, 23: 21-23.
9. Lof, G.L. (2002). Two comments on this assessment series. American Journal of Speech-Language Pathology, 11: 255-56.
10. Lof, G. (2003). Oral motor exercises and treatment outcomes. Perspectives on Language Learning and Education, 10 (1): 7-11.
Jennifer Bathel is director of research at Talk Tools in Tucson, AZ. She can be contacted at firstname.lastname@example.org.