Interview with Gregory L. Lof, Ph.D., CCC-SLP, Associate Professor/Associate Director, MGH Institute of Health Professions, Boston, MA
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Schreiber: Good morning Gregg. Thank you for taking the time to talk with me this morning. Let's tell the readers a little bit about your background.Lof: I'm at the MGH Institute of Health Professions. It's an academic affiliate of the Massachusetts General Hospital, a graduate only, masters trainin
Schreiber: Good morning Gregg. Thank you for taking the time to talk with me this morning. Let's tell the readers a little bit about your background.
Lof: I'm at the MGH Institute of Health Professions. It's an academic affiliate of the Massachusetts General Hospital, a graduate only, masters training program. I'm an associate professor and the associate director in the graduate program. My main area of interest is with childhood speech sound disorders. And recently I've become interested in the controversies surrounding non-speech oral motor exercises (referred to as
NS-OMEs) to change speech sound productions.
Schreiber: Your ASHA presentation titled Logic, Theory, and Evidence against Using Oral Motor Exercises to Change Speech Productions addressed this controversy and I'm hoping you'll share some of the information with our readers. First, let's define NS-OMEs.
Lof: Sure and that's a good place to start. I'm on a newly formed ASHA National Center for Evidence-Based Practice Committee. We are charged with looking at the evidence on using NS-OMEs for speaking and nonspeaking tasks such as feeding, swallowing, and drooling. One of our first missions is to come up with a definition and we're finding it's not as easy as we thought. As a starting point, one of the ways that Dr. Maggie Watson (from the University of Wisconsin-Stevens Point) and I think about the definition is that non-speech oral motor exercises are "any techniques that do not require the child to produce a speech sound but are used to influence the development of speaking abilities." So it's anything that we're doing with the mouth that's not speaking with the idea that these exercises or these things that we're doing with the mouth are going to transfer over to speaking.
Schreiber: And you believe that speech-language pathologists are using oral motor exercises in their interventions with children who have speech sound production disorders?
Lof: Yes. Dr. Maggie Watson and I did a study about a year and a half ago, and these data are presented in an article in Language, Speech, and Hearing Services in the Schools that will be published in 2007. We did a nation-wide survey and found that 85% of speech-language pathologists are using NS-OMEs to change speech sound productions. One of the interesting things is that, Dr. Megan Hodge and colleagues in Canada didn't know that we conducted this study but they did a survey asking very similar questions of speech-language pathologists (SLPs) in Canada. They had 535 people respond, we had 537, and interestingly they came up with the same exact number; 85% of speech-language pathologists are using NS-OMEs to change speech sound productions.
Schreiber: That's interesting data. And the SLPs who use non-speech oral motor exercises believe there is evidence for using this approach, correct?
Lof: Well that's the funny thing. Evidence-based practice really forces us to look at peer-reviewed articles to get our information. When you use evidence-based practice, you have to read more than non peer-reviewed journals or non peer-reviewed publications. And when you read peer-reviewed articles and other forms of evidence, there is no evidence to support the use of NS-OMEs. In fact, there's counter-evidence for using them. However, if you read the non peer-reviewed literature, you find statements that say the exercises should be used to change speech sound productions. Once again, these are non peer-reviewed and they're usually written by people who are selling products for the exercises. I think what's happened is that SLPs attend continuing education events, which are not peer-reviewed, and learn to use the oral motor exercises. In fact our data show that that's how most people found out about using NS-OMEs; 87% of the clinicians we surveyed said that's how they learned to use NS-OMEs, through these non peer-reviewed CEU events. And I think a lot of the continuing education events also sell products for oral motor exercises.
Schreiber: Tell us more about the kinds of exercises you are talking about.
Lof: Oh you know, all you have to do is go online or open one of the many catalogs we get in the mail and you'll find so many different types of exercises. You will see things like blowing, tongue push-ups, pucker-smile, tongue wagging, tongue-to-nose-to-chin stretches, cheek puffing, tongue curling, and many other exercises that involve the different articulators. Also, some people would classify tasks such as using vibration, horns, or blowing cotton balls to be different types of NS-OMEs.
Schreiber: And these exercises are meant to strengthen the articulators?
Lof: Well you and I will talk about strength in a little bit but people use these exercises for many different purposes for strengthening, for awareness with the idea that non-speech exercises provide an underlying foundation for later speaking. These assumptions need to be questioned because most of them aren't true.
Schreiber: Let's return for a minute to your comment about evidence-based practice. You're on an ASHA committee that's looking at evidence-based practices. Remind readers of why we need to be aware of what is evidence-based.
Lof: I keep thinking back to the 1980s and 90s when we thought we saw facilitated communication (FC) working. And when you look at it on the surface level, it sure appeared that people who had severe handicaps were being proficient in communication using FC. And we thought it was a new paradigm in the way we needed to treat kids with severe communication disorders because it appeared that FC worked. Well, once we put it to scientifically rigorous testing, it was shown that it did not work. And so I think that really brings home to me the idea that just because something looks like it works, doesn't mean that it does work. And we need to start thinking about things in a scientific way. We need to become, I think, scientific clinicians. The art of speech-language pathology is important but so is the science of speech-language pathology. The science has to guide our art. The science is the evidence. What does the theory and the data actually show about the different types of treatment approaches? We can use the evidence to guide what we are doing in clinical practice, so we aren't making big mistakes like we did with FC.
Schreiber: And again you're saying that the articles that report anecdotal information, comments, changes observed, or experiences really are not evidence-based?
Lof: Researchers have always known that case studies never have been able to be used to determine cause and effect. Case studies can bring out interesting types of treatment with interesting clients, but they can't document any kind of cause-and-effect relationship. They can't guide us and show that this will work for the general population. That never was the purpose of case studies. So I think we have to really be careful whenever we see this anecdotal information, especially from case studies.
Schreiber: Let's talk about some of the basic questions you addressed in your ASHA presentation. The questions parallel the reasons clinicians give for using oral motor exercises. One of the reasons given is that by using oral motor exercises, a part of the articulation movement is trained in an effort to transfer it to the whole movement. What did you find out in that regard?
Lof: Yeah, that's a reason that always comes up. It's actually called part-whole training and transfer. The question is, if you train on just a part of the whole gesture; will that teaching of the part transfer over to the whole? And interestingly enough, Dr. Karen Forest at Indiana University did a wonderful job of discussing this in her article. Training the parts really doesn't work. Tasks that are highly organized are not enhanced by being broken down into smaller chunks. This is called fractionating. And fractionating a behavior isn't going to provide the relevant information that is going to change the neural substrate. That's what we're really doing when we do therapy. We're trying to change the thought process, trying to change the neurology of how pathways are established. And by breaking the whole target down into smaller chunks, it will not happen. In fact, there is sound information in the phonology literature that demonstrates that breaking things down into small, meaningless chunks will not transfer over to speech. Dr. David Ingram, Dr. Shelley Velleman, and Dr. Marilyn Vihman have all talked about how you need to train the whole and not the smaller chunks because there won't be any transfer.
Schreiber: OK, but some SLPs also make the case that the oral motor exercises are producing strength in the articulatory structures.
Lof: Boy, we hear about the strength reason all the time that the child needs strength to talk and how oral motor exercises are important for strengthening. There are some real problems with these reasons, Linda. One of the problems is, how do you measure strength? Strength is a tough one because you can't just look at someone and say, "Oh, those are weak muscles." You'd have to actually do some kind of measurement of strength. And I don't think many speech-language pathologists do nonsubjective strength measurements. But without valid measurements of strength, how can you say an articulator is weak? And then once you do therapy, how can you come back and say "Oh, I have strengthened that articulator" when all you're using are subjective measures of strength? That's one of the big problems: how do we really know if there is a strength problem? Another big problem with the strength argument is that we don't need very strong articulators to speak. Most of the data are showing that we use very little of the available strength in order to talk. We don't need strong articulators. What we need are agile articulators, articulators that can move quickly and have fast ballistic movements. They don't need to be very strong. It's interesting; there was a study that was presented at the ASHA convention this year that showed that kids with articulation disorders actually had stronger tongues than kids who didn't have an articulation problem. So that kind of flies in the face of what some clinicians believe about kids with speech problems having weak articulators.
Schreiber: That's an interesting finding.
Lof: Yes, that was an interesting finding. It really makes you question whether you should be doing strengthening exercises. And I guess that goes back to another question, are we really strengthening the articulatory structures when we do these oral motor exercises? Think about going to the gym and lifting weights. You have to lift a lot of weights, with resistance, usually to failure, and you have to do it over and over and over again. It takes a lot to strengthen muscle. Most speech-language pathologists probably aren't doing enough exercises to actually strengthen the muscles, especially if the exercises are not done against resistance. So it may look like you're strengthening muscles, but you really probably aren't. So the same muscle strengthening that is used in the gym is needed in speech therapy if clinicians want to strengthen the articulators: exercising with resistance, to muscle failure due to multiple repetitions, and then doing it again and again. Otherwise, muscles are not being strengthened. But then again, do they need to be strengthened? Probably not.
Schreiber: Good points. So you also looked at how relevant the NS-OMEs are to speech in general, in terms of the neural pathways.
Lof: A little bit earlier in this interview you asked what kinds of exercises people are using. Well think about some of the crazy exercises used: these oral motor exercises have absolutely nothing to do with speech. For example, biting your lower lip multiple times is not the gesture we use for the "f" sound. Or sticking your tongue up to your nose, well, we don't stick our tongue up to our nose in order to talk. So why are we training a gesture that isn't even used for speaking? Now relevancy is really an important thing because relevancy is how we set up and change the neural system. Muscle fibers and the neural anatomy are based on the task that is being performed, not on the muscles performing the task.
There was another presentation at the ASHA Convention this year that demonstrated this. It was an fMRI study where they had the individual perform non-speech tasks and then did a brain scan. And then they had the individual do speech tasks that were very similar and did another brain scan. They showed that different parts of the brain were activated for the speech and the non-speech tasks. That's because of task specificity. Different tasks, even though they're using the same structures, are represented differently in the brain. That's an important concept task specificity. Neurological control of muscles are developed and set up based on the task, not on the muscle itself. So if you want things to transfer from movement to speaking, that movement must be done with a relevant task (i.e., task specificity). Just because you use the same structures for feeding, for tongue exercises, etc., doesn't mean that they have the same function. Remember, same structures, but different function.
Schreiber: What you're saying is very logical. But what do you say to the SLPs who say they are just using the exercises for warm-up, for some awareness of the structures within the mouth, and the warm-up will carry over to speech sound production?
Lof: I do hear this "metamouth" idea all the time this idea that we need to warm-up the mouth. There's a couple of ways of thinking about warm-up. One way to look at warm-up is, do we really need to warm-up those muscles of the mouth? Think about when you go jogging. If you're going jogging, you had better warm-up those muscles for running. However, if you're just going out for a walk, you don't need to warm-up those muscles. And the reason for that is you aren't taxing the system. Because you don't need to warm-up those muscles if you aren't taxing the system for walking, but you do for running. Well, for talking we've already established that we use about 10 percent of the maximum of the muscles used for talking. We don't need to warm those up because they don't need warming up. You know, when you wake up in the morning you don't have to warm-up your mouth to say "good morning." Your mouth is already ready to say "good morning.". So warm-up is a questionable idea, but I guess a lot of people think of warm-up more as getting kids to know that their mouths exist. I think a lot of us have used mirrors in therapy and tongue depressors in therapy so that we could tap the alveolar ridge and say "put your tongue here." Now that, of course, is a phonetic placement cue, not an oral motor exercise. And that's fine. And we know since the 1920s that those phonetic placement cues work. That's not an oral motor exercise.
Kids have a great deal of difficulty knowing much about their mouths. There is very little research that's been conducted on this, and much more needs to be done to determine how much kids know about their mouths and how those structures move. Dr. Harriet Klein and some of her colleagues did an interesting study and they found that even seven-year-olds don't know much about their mouths. It's kind of funny when I teach college students phonetic transcription and place, manner, and voicing characteristics in beginning courses of speech-language pathology, I'm always amazed at how much the students don't know about their mouths. So I think it's asking an awful lot of young kids to even know that their mouths exist. I doubt if we're probably giving them much awareness of their mouths.
Schreiber: Does all of what you're saying about NS-OMEs apply to clients with speech sound disorders that are the result of childhood apraxia of speech, motor speech disorders, or cleft lip or palate? Are you saying there may not be value in oral motor exercises for them as well?
Lof: Well let me break that down into two different areas for this discussion. First, would we do a motor-based approach for children who don't have a motor-based speaking problem, as an example, for those who have a language problem? Why would you use a motor-based speech approach for children who have a phonological impairment, when their problem isn't motor based? Their problem is linguistically based. And so we see this with our late talkers. Why would we have kids who are, by definition, having trouble with the linguistic aspects of talking, use a motor approach? That doesn't make sense to me at all. Kids whose speech delay is associated with hearing loss don't have a motor problem so would you use a motor approach to remediate their sound errors?
Now some people would say that children with childhood apraxia of speech do have a motor component, but by definition, children who have childhood apraxia of speech have adequate oral structure movements for non-speech activities. It's the SPEECH activities that are a problem. So why would you work on the areas of non-speech when, by definition, that's not their problem? If they have problems with the non-speech activities and they've got weakness and paralysis, then they don't have apraxia, they have dysarthria.
Schreiber: And children with cleft lip or cleft palate? Are there any benefits?
Lof: The blowing exercises, like blowing cotton balls, which is probably typically done, are not going to bring about changes in nasality. Since the early 1960s, the research is clear that the exercises do not help kids with their velopharyngeal incompetence. A book just released that is really very good on this topic is called The Clinician's Guide to Treating Cleft Palate Speech (by Peterson-Falzone, Trost-Cardamone, Karnell, & Hardin-Jones); the authors discuss oral motor exercises quite extensively and talk about the exercises from a physiological viewpoint and why they just don't work.
Schreiber: So all of what you have told me thus far is based on the evidence you compiled upon combing though the literature on NS-OME. Would you summarize the results of what you looked at?
Lof: Sure. Evidence both against and for oral motor exercises to change speech sound productions really is very limited. And what evidence we do have, is at very low level according to the evidence-based paradigm. Most of the literature we have is presented at peer-reviewed convention presentations. There are very few published studies. So I guess I do need to give caution that the data that we have, the evidence, is not as good or as strong as we would like. And when we don't have good evidence, we have to fall back on theory. And as I've just talked with you about task specificity, relevancy to the task, and of strengthening, these theoretical concepts don't encourage us to use NS-OME. But we do have some evidence, it's not as good or strong as we would like, but we do have evidence. I was able to locate about 10 different studies that have directly evaluated the exercises. Of the 10 studies I found, 9 showed that oral motor exercises didn't work. And I only found one that showed that it did work. Unfortunately, the one that reported that it did work has some very questionable methodologies. These flaws have been pointed out by others, like Dr. Norm Lass and Dr. Dennis Ruscello, in articles that are coming out in Language, Speech, and Hearing Service in the Schools. The flaws make that one study questionable; so I guess the evidence, even though it's not as high of a level on the hierarchy of evidence-based practice that we'd like to see, the evidence that we do have, is pretty clear that it doesn't work.
Schreiber: If our readers would like to see specifically the studies you have reviewed, can they contact you?
Lof: I have reviewed most of these in the handout that I have from the ASHA 2006 Convention. But there's also going to be a special series in Language, Speech, and Hearing Service in the Schools coming out in 2007 that will include a review of the studies, and will discuss theory and philosophy. That series will also include Dr. Maggie Watson's and my study on frequency of use by practitioners. That'll all be published in 2007.
Schreiber: OK, we'll watch for those articles. Do you have any concluding remarks?
Lof: I just think that as clinicians we need to be thinking about evidence. And we need to be thinking about evaluating what we're doing in every type of therapy. We should be questioning everything that we're doing. But I think once we start questioning oral motor exercise, we start seeing that it just doesn't hold up theoretically. And the evidence is showing that it isn't the type of therapy that's going to improve children's speech sound productions. One of the things you oftentimes hear people say is "Well, I do a combined treatment approach. I do oral motor exercises and something else." Well it appears to me from the literature and the theories that doing oral motor exercises along with that "something else," that if you just did that "something else" and eliminated the oral motor exercise part, kids will get better just as rapidly. Therapy time is way too important and we don't have enough time to sit around with children doing things that aren't going to give us the biggest "bang for our buck" or help them the most. I think we need to be questioning what's going on, think about it, read about it, and not just take things at face value. Go ahead and study it and do the things that work in therapy. We already know from the literature what works in changing speech sound productions in children. I think we should continue to do those things that we know work.
Schreiber: Great Gregg. I hope this interview will help SLPs rethink their use of oral motor exercise and the importance of using evidence-based approaches. Thank you so much for your interview today. We appreciate your work on the ASHA committee as well.
Lof: I'm at the MGH Institute of Health Professions. It's an academic affiliate of the Massachusetts General Hospital, a graduate only, masters training program. I'm an associate professor and the associate director in the graduate program. My main area of interest is with childhood speech sound disorders. And recently I've become interested in the controversies surrounding non-speech oral motor exercises (referred to as
NS-OMEs) to change speech sound productions.
Schreiber: Your ASHA presentation titled Logic, Theory, and Evidence against Using Oral Motor Exercises to Change Speech Productions addressed this controversy and I'm hoping you'll share some of the information with our readers. First, let's define NS-OMEs.
Lof: Sure and that's a good place to start. I'm on a newly formed ASHA National Center for Evidence-Based Practice Committee. We are charged with looking at the evidence on using NS-OMEs for speaking and nonspeaking tasks such as feeding, swallowing, and drooling. One of our first missions is to come up with a definition and we're finding it's not as easy as we thought. As a starting point, one of the ways that Dr. Maggie Watson (from the University of Wisconsin-Stevens Point) and I think about the definition is that non-speech oral motor exercises are "any techniques that do not require the child to produce a speech sound but are used to influence the development of speaking abilities." So it's anything that we're doing with the mouth that's not speaking with the idea that these exercises or these things that we're doing with the mouth are going to transfer over to speaking.
Schreiber: And you believe that speech-language pathologists are using oral motor exercises in their interventions with children who have speech sound production disorders?
Lof: Yes. Dr. Maggie Watson and I did a study about a year and a half ago, and these data are presented in an article in Language, Speech, and Hearing Services in the Schools that will be published in 2007. We did a nation-wide survey and found that 85% of speech-language pathologists are using NS-OMEs to change speech sound productions. One of the interesting things is that, Dr. Megan Hodge and colleagues in Canada didn't know that we conducted this study but they did a survey asking very similar questions of speech-language pathologists (SLPs) in Canada. They had 535 people respond, we had 537, and interestingly they came up with the same exact number; 85% of speech-language pathologists are using NS-OMEs to change speech sound productions.
Schreiber: That's interesting data. And the SLPs who use non-speech oral motor exercises believe there is evidence for using this approach, correct?
Lof: Well that's the funny thing. Evidence-based practice really forces us to look at peer-reviewed articles to get our information. When you use evidence-based practice, you have to read more than non peer-reviewed journals or non peer-reviewed publications. And when you read peer-reviewed articles and other forms of evidence, there is no evidence to support the use of NS-OMEs. In fact, there's counter-evidence for using them. However, if you read the non peer-reviewed literature, you find statements that say the exercises should be used to change speech sound productions. Once again, these are non peer-reviewed and they're usually written by people who are selling products for the exercises. I think what's happened is that SLPs attend continuing education events, which are not peer-reviewed, and learn to use the oral motor exercises. In fact our data show that that's how most people found out about using NS-OMEs; 87% of the clinicians we surveyed said that's how they learned to use NS-OMEs, through these non peer-reviewed CEU events. And I think a lot of the continuing education events also sell products for oral motor exercises.
Schreiber: Tell us more about the kinds of exercises you are talking about.
Lof: Oh you know, all you have to do is go online or open one of the many catalogs we get in the mail and you'll find so many different types of exercises. You will see things like blowing, tongue push-ups, pucker-smile, tongue wagging, tongue-to-nose-to-chin stretches, cheek puffing, tongue curling, and many other exercises that involve the different articulators. Also, some people would classify tasks such as using vibration, horns, or blowing cotton balls to be different types of NS-OMEs.
Schreiber: And these exercises are meant to strengthen the articulators?
Lof: Well you and I will talk about strength in a little bit but people use these exercises for many different purposes for strengthening, for awareness with the idea that non-speech exercises provide an underlying foundation for later speaking. These assumptions need to be questioned because most of them aren't true.
Schreiber: Let's return for a minute to your comment about evidence-based practice. You're on an ASHA committee that's looking at evidence-based practices. Remind readers of why we need to be aware of what is evidence-based.
Lof: I keep thinking back to the 1980s and 90s when we thought we saw facilitated communication (FC) working. And when you look at it on the surface level, it sure appeared that people who had severe handicaps were being proficient in communication using FC. And we thought it was a new paradigm in the way we needed to treat kids with severe communication disorders because it appeared that FC worked. Well, once we put it to scientifically rigorous testing, it was shown that it did not work. And so I think that really brings home to me the idea that just because something looks like it works, doesn't mean that it does work. And we need to start thinking about things in a scientific way. We need to become, I think, scientific clinicians. The art of speech-language pathology is important but so is the science of speech-language pathology. The science has to guide our art. The science is the evidence. What does the theory and the data actually show about the different types of treatment approaches? We can use the evidence to guide what we are doing in clinical practice, so we aren't making big mistakes like we did with FC.
Schreiber: And again you're saying that the articles that report anecdotal information, comments, changes observed, or experiences really are not evidence-based?
Lof: Researchers have always known that case studies never have been able to be used to determine cause and effect. Case studies can bring out interesting types of treatment with interesting clients, but they can't document any kind of cause-and-effect relationship. They can't guide us and show that this will work for the general population. That never was the purpose of case studies. So I think we have to really be careful whenever we see this anecdotal information, especially from case studies.
Schreiber: Let's talk about some of the basic questions you addressed in your ASHA presentation. The questions parallel the reasons clinicians give for using oral motor exercises. One of the reasons given is that by using oral motor exercises, a part of the articulation movement is trained in an effort to transfer it to the whole movement. What did you find out in that regard?
Lof: Yeah, that's a reason that always comes up. It's actually called part-whole training and transfer. The question is, if you train on just a part of the whole gesture; will that teaching of the part transfer over to the whole? And interestingly enough, Dr. Karen Forest at Indiana University did a wonderful job of discussing this in her article. Training the parts really doesn't work. Tasks that are highly organized are not enhanced by being broken down into smaller chunks. This is called fractionating. And fractionating a behavior isn't going to provide the relevant information that is going to change the neural substrate. That's what we're really doing when we do therapy. We're trying to change the thought process, trying to change the neurology of how pathways are established. And by breaking the whole target down into smaller chunks, it will not happen. In fact, there is sound information in the phonology literature that demonstrates that breaking things down into small, meaningless chunks will not transfer over to speech. Dr. David Ingram, Dr. Shelley Velleman, and Dr. Marilyn Vihman have all talked about how you need to train the whole and not the smaller chunks because there won't be any transfer.
Schreiber: OK, but some SLPs also make the case that the oral motor exercises are producing strength in the articulatory structures.
Lof: Boy, we hear about the strength reason all the time that the child needs strength to talk and how oral motor exercises are important for strengthening. There are some real problems with these reasons, Linda. One of the problems is, how do you measure strength? Strength is a tough one because you can't just look at someone and say, "Oh, those are weak muscles." You'd have to actually do some kind of measurement of strength. And I don't think many speech-language pathologists do nonsubjective strength measurements. But without valid measurements of strength, how can you say an articulator is weak? And then once you do therapy, how can you come back and say "Oh, I have strengthened that articulator" when all you're using are subjective measures of strength? That's one of the big problems: how do we really know if there is a strength problem? Another big problem with the strength argument is that we don't need very strong articulators to speak. Most of the data are showing that we use very little of the available strength in order to talk. We don't need strong articulators. What we need are agile articulators, articulators that can move quickly and have fast ballistic movements. They don't need to be very strong. It's interesting; there was a study that was presented at the ASHA convention this year that showed that kids with articulation disorders actually had stronger tongues than kids who didn't have an articulation problem. So that kind of flies in the face of what some clinicians believe about kids with speech problems having weak articulators.
Schreiber: That's an interesting finding.
Lof: Yes, that was an interesting finding. It really makes you question whether you should be doing strengthening exercises. And I guess that goes back to another question, are we really strengthening the articulatory structures when we do these oral motor exercises? Think about going to the gym and lifting weights. You have to lift a lot of weights, with resistance, usually to failure, and you have to do it over and over and over again. It takes a lot to strengthen muscle. Most speech-language pathologists probably aren't doing enough exercises to actually strengthen the muscles, especially if the exercises are not done against resistance. So it may look like you're strengthening muscles, but you really probably aren't. So the same muscle strengthening that is used in the gym is needed in speech therapy if clinicians want to strengthen the articulators: exercising with resistance, to muscle failure due to multiple repetitions, and then doing it again and again. Otherwise, muscles are not being strengthened. But then again, do they need to be strengthened? Probably not.
Schreiber: Good points. So you also looked at how relevant the NS-OMEs are to speech in general, in terms of the neural pathways.
Lof: A little bit earlier in this interview you asked what kinds of exercises people are using. Well think about some of the crazy exercises used: these oral motor exercises have absolutely nothing to do with speech. For example, biting your lower lip multiple times is not the gesture we use for the "f" sound. Or sticking your tongue up to your nose, well, we don't stick our tongue up to our nose in order to talk. So why are we training a gesture that isn't even used for speaking? Now relevancy is really an important thing because relevancy is how we set up and change the neural system. Muscle fibers and the neural anatomy are based on the task that is being performed, not on the muscles performing the task.
There was another presentation at the ASHA Convention this year that demonstrated this. It was an fMRI study where they had the individual perform non-speech tasks and then did a brain scan. And then they had the individual do speech tasks that were very similar and did another brain scan. They showed that different parts of the brain were activated for the speech and the non-speech tasks. That's because of task specificity. Different tasks, even though they're using the same structures, are represented differently in the brain. That's an important concept task specificity. Neurological control of muscles are developed and set up based on the task, not on the muscle itself. So if you want things to transfer from movement to speaking, that movement must be done with a relevant task (i.e., task specificity). Just because you use the same structures for feeding, for tongue exercises, etc., doesn't mean that they have the same function. Remember, same structures, but different function.
Schreiber: What you're saying is very logical. But what do you say to the SLPs who say they are just using the exercises for warm-up, for some awareness of the structures within the mouth, and the warm-up will carry over to speech sound production?
Lof: I do hear this "metamouth" idea all the time this idea that we need to warm-up the mouth. There's a couple of ways of thinking about warm-up. One way to look at warm-up is, do we really need to warm-up those muscles of the mouth? Think about when you go jogging. If you're going jogging, you had better warm-up those muscles for running. However, if you're just going out for a walk, you don't need to warm-up those muscles. And the reason for that is you aren't taxing the system. Because you don't need to warm-up those muscles if you aren't taxing the system for walking, but you do for running. Well, for talking we've already established that we use about 10 percent of the maximum of the muscles used for talking. We don't need to warm those up because they don't need warming up. You know, when you wake up in the morning you don't have to warm-up your mouth to say "good morning." Your mouth is already ready to say "good morning.". So warm-up is a questionable idea, but I guess a lot of people think of warm-up more as getting kids to know that their mouths exist. I think a lot of us have used mirrors in therapy and tongue depressors in therapy so that we could tap the alveolar ridge and say "put your tongue here." Now that, of course, is a phonetic placement cue, not an oral motor exercise. And that's fine. And we know since the 1920s that those phonetic placement cues work. That's not an oral motor exercise.
Kids have a great deal of difficulty knowing much about their mouths. There is very little research that's been conducted on this, and much more needs to be done to determine how much kids know about their mouths and how those structures move. Dr. Harriet Klein and some of her colleagues did an interesting study and they found that even seven-year-olds don't know much about their mouths. It's kind of funny when I teach college students phonetic transcription and place, manner, and voicing characteristics in beginning courses of speech-language pathology, I'm always amazed at how much the students don't know about their mouths. So I think it's asking an awful lot of young kids to even know that their mouths exist. I doubt if we're probably giving them much awareness of their mouths.
Schreiber: Does all of what you're saying about NS-OMEs apply to clients with speech sound disorders that are the result of childhood apraxia of speech, motor speech disorders, or cleft lip or palate? Are you saying there may not be value in oral motor exercises for them as well?
Lof: Well let me break that down into two different areas for this discussion. First, would we do a motor-based approach for children who don't have a motor-based speaking problem, as an example, for those who have a language problem? Why would you use a motor-based speech approach for children who have a phonological impairment, when their problem isn't motor based? Their problem is linguistically based. And so we see this with our late talkers. Why would we have kids who are, by definition, having trouble with the linguistic aspects of talking, use a motor approach? That doesn't make sense to me at all. Kids whose speech delay is associated with hearing loss don't have a motor problem so would you use a motor approach to remediate their sound errors?
Now some people would say that children with childhood apraxia of speech do have a motor component, but by definition, children who have childhood apraxia of speech have adequate oral structure movements for non-speech activities. It's the SPEECH activities that are a problem. So why would you work on the areas of non-speech when, by definition, that's not their problem? If they have problems with the non-speech activities and they've got weakness and paralysis, then they don't have apraxia, they have dysarthria.
Schreiber: And children with cleft lip or cleft palate? Are there any benefits?
Lof: The blowing exercises, like blowing cotton balls, which is probably typically done, are not going to bring about changes in nasality. Since the early 1960s, the research is clear that the exercises do not help kids with their velopharyngeal incompetence. A book just released that is really very good on this topic is called The Clinician's Guide to Treating Cleft Palate Speech (by Peterson-Falzone, Trost-Cardamone, Karnell, & Hardin-Jones); the authors discuss oral motor exercises quite extensively and talk about the exercises from a physiological viewpoint and why they just don't work.
Schreiber: So all of what you have told me thus far is based on the evidence you compiled upon combing though the literature on NS-OME. Would you summarize the results of what you looked at?
Lof: Sure. Evidence both against and for oral motor exercises to change speech sound productions really is very limited. And what evidence we do have, is at very low level according to the evidence-based paradigm. Most of the literature we have is presented at peer-reviewed convention presentations. There are very few published studies. So I guess I do need to give caution that the data that we have, the evidence, is not as good or as strong as we would like. And when we don't have good evidence, we have to fall back on theory. And as I've just talked with you about task specificity, relevancy to the task, and of strengthening, these theoretical concepts don't encourage us to use NS-OME. But we do have some evidence, it's not as good or strong as we would like, but we do have evidence. I was able to locate about 10 different studies that have directly evaluated the exercises. Of the 10 studies I found, 9 showed that oral motor exercises didn't work. And I only found one that showed that it did work. Unfortunately, the one that reported that it did work has some very questionable methodologies. These flaws have been pointed out by others, like Dr. Norm Lass and Dr. Dennis Ruscello, in articles that are coming out in Language, Speech, and Hearing Service in the Schools. The flaws make that one study questionable; so I guess the evidence, even though it's not as high of a level on the hierarchy of evidence-based practice that we'd like to see, the evidence that we do have, is pretty clear that it doesn't work.
Schreiber: If our readers would like to see specifically the studies you have reviewed, can they contact you?
Lof: I have reviewed most of these in the handout that I have from the ASHA 2006 Convention. But there's also going to be a special series in Language, Speech, and Hearing Service in the Schools coming out in 2007 that will include a review of the studies, and will discuss theory and philosophy. That series will also include Dr. Maggie Watson's and my study on frequency of use by practitioners. That'll all be published in 2007.
Schreiber: OK, we'll watch for those articles. Do you have any concluding remarks?
Lof: I just think that as clinicians we need to be thinking about evidence. And we need to be thinking about evaluating what we're doing in every type of therapy. We should be questioning everything that we're doing. But I think once we start questioning oral motor exercise, we start seeing that it just doesn't hold up theoretically. And the evidence is showing that it isn't the type of therapy that's going to improve children's speech sound productions. One of the things you oftentimes hear people say is "Well, I do a combined treatment approach. I do oral motor exercises and something else." Well it appears to me from the literature and the theories that doing oral motor exercises along with that "something else," that if you just did that "something else" and eliminated the oral motor exercise part, kids will get better just as rapidly. Therapy time is way too important and we don't have enough time to sit around with children doing things that aren't going to give us the biggest "bang for our buck" or help them the most. I think we need to be questioning what's going on, think about it, read about it, and not just take things at face value. Go ahead and study it and do the things that work in therapy. We already know from the literature what works in changing speech sound productions in children. I think we should continue to do those things that we know work.
Schreiber: Great Gregg. I hope this interview will help SLPs rethink their use of oral motor exercise and the importance of using evidence-based approaches. Thank you so much for your interview today. We appreciate your work on the ASHA committee as well.