RESEARCH: EXPOSURE RESPONSE IN A RESEARCH MODE

Essential to the prevention, reduction, or management of musculoskeletal illnesses is the establishment of definite relationships, where they exist, between the outcome condition or response and the various exposure stress factors including: ergonomic, physical, psychosocial factors and individual differences in susceptibility.

Although the exposure response relationship may be complex and uniquely individual in many instances, modern epidemiology is challenged to provide accurate and meaningful groupings and characterizations of work exposures and pathological responses in order to ascertain where dose response relationships exist and to provide useful guidance for workplace intervention and control  and for public policy.

Session Arrangers
Steven H. Lamm, MD, President, Consultants in Epidemiology and Occupational Health
Thomas J. Armstrong, PhD, MPH, Professor, University of Michigan School of Public Health

Presenters

Robert F. Bettendorf, Executive Director, Office Ergonomics Research Committee
The OERC Framework for Understanding Upper-Extremity Musculoskeletal Disorders Research, Theory and Management

Jacqueline Agnew, PhD, MPH, Assc. Prof., Johns Hopkins University School of Public Health
Identification of Research Needs for Epidemiology of Work-Related Musculoskeletal Disorders

Steven L. Sauter, PhD, Chief, Applied Psychology and Ergonomics Branch, NIOSH
Organizational Risk Factors for Musculoskeletal Disorders: Theory and Evidence

Alfred Franzblau, MD, Dir., Occup. Medicine Residency Program, University of Michigan
A Cross-Sectional Study of the Relationship Between Repetitive Work and Upper Extremity Musculoskeletal Disorders

Discussants

Robert G. Radwin, PhD, Prof. of Industrial Engineering, University of Wisconsin-Madison
Scott P. Schneider, CIH, Ergonomics Program Dir., Center to Protect Worker's Rights
Bradley S. Joseph, PhD, Corporate Ergonomist, Ford Motor Company

Mr. DAVID FELINSKI, AAMA

Good morning ladies and gentlemen. I am Dave Felinski with AAMA, and on behalf of our conference co-sponsor, the Center for Office Technology, I am pleased to welcome you all to day two of the Managing Ergonomics Conference. I would also like to introduce our Session Moderator for this morning's session on Research and Exposure Response in a Research Mode -- Dr. Steven Lamm.

Dr. Lamm is a physician epidemiologist and has been head of Consultants in Epidemiology and Occupational Health, Inc. in Washington D.C. since 1981. He has a Master's Degree in biophysics from the University of Southern California, and he is board certified in Pediatrics, Preventive Medicine and Occupational Medicine, and is a charter fellow of the American College of Epidemiology. He has been active in the American Industrial Hygiene Association for over 20 years, and is on the editorial review board of their journal. He is on the faculty at Johns Hopkins University and the Uniform Services University of the Health Sciences. Dr. Lamm, the session is yours.

Dr. STEVEN LAMM, Consultants in Epidemiology and Occupational Health (CEOH)

Thank you. The subject matter for this morning is research. Specifically, exposure response in the research mode. Originally when we planned this session, we expected that we would have four presentations, each of which would look specifically at an exposure variable and look at the relationship between the exposure variable and the outcome variable. That's what epidemiologists do. Our concern is what is the disease we're talking about, what are the risk factors, or exposure factors, that: a) we can measure; b) we can control; and, c) we can do something about under the argument that reducing the exposure to the risk factor will reduce the incidence or prevalence of the condition. As we got into this, we found the difficulty with starting off at that point is that we are not quite sure, as we heard from yesterday's presentation, what outcome is it that we're talking about? What specific disease? How do we define it? And we get into a whole set of arguments about how do we define the exposure variable and how do we measure the exposure variable? And measure it in such a way that we may have some way of intervening and changing the frequency or prevalence of that exposure variable. In view of this, we're beginning our session first by dealing with that out of fashion term called a 'research paradigm.' That is, let us start off by trying to define what we are talking about in a global sense. What are the variety of factors that ought to be considered. And for that presentation we will be hearing from Robert Bettendorf who is the Executive Director of the Office of Ergonomic Research Committee. He will be followed by Dr. Jacqueline Agnew who is the Associate Director of the Program on VDT and Health from which we had presentations yesterday, the group at Johns Hopkins. And basically what I expect you will hear from her is from the 35 variables that we have to consider, let's identify which are the principle ones and let's identify how we are going to agree on a nomenclature, criteria and definition of both the outcome variable and the exposure variable.

Our third presentation will be by Steve Sauter - Dr. Sauter from the National Institute for Occupational Safety and Health, head of the Applied Physiology Program. He will look specifically at the issues of the psychosocial variables as exposure factors, and assist us in beginning to ferret out from among the complex terminology that is used, how do we go about identifying specific variables that we can assess in the work place and begin to measure to what degree they contribute to the outcome or to the diseases that we're concerned about.

Our final presentation will be by Dr. Alfred Franzblau. Dr. Franzblau is head of the Occupational Medicine Residency Program at the University of Michigan School of Public Health. He will present a study that they have recently completed in which they have focused in quite narrowly on the defined exposure, taken one variable - in this case, repetition, as the exposure variable, and held that constant throughout the variety of study sites that they've been to. And then in each of the study sites, they looked at a variety of definitions of outcome of disease in order to say, given that one variable, how we find it influencing the prevalence or association for each of these various definitions of outcome that we think may or may not be relevant to the issues of the day. And that is the design of the session this morning. I would like to begin now with Mr. Bettendorf.

>Bob Bettendorf >has been involved in ergonomics and particularly in keyboard problems for about 25 years with IBM before he moved into establishing the Office for Ergonomic Research in the Office, and we will now here from him. Thank you.

Dr. Steven Lamm, CEOH

Thank you very much, Bob. Our next speaker is Dr. Jacqueline Agnew. Dr. Agnew, as I previously informed you, is at Johns Hopkins University where she has been conducting research in epidemiology workplace problems and aging aspects for many years. She is now focusing her attention onto the issues of ergonomics and the definition of the conditions and exposure variables. Dr. Agnew.

Dr. Steven Lamm, CEOH

Thank you very much, Dr. Agnew. Our next speaker is Dr. Steven Sauter. Dr. Sauter is a psychologist who's been actively heading the program at NIOSH looking at issues of psychosocial aspects of musculoskeletal disorders. He recently co-edited a book by that title. He will speak now about his research and about the ways for trying to identify what variables to measure with respect to psychosocial aspects, and what would be variables where one can intervene and make changes. Thank you.

Dr. Steven Lamm, CEOH

Thank you very much, Steve. Our last presenter for this morning is Dr. Alfred Franzblau. Dr. Franzblau is Director of the Occupational Medicine Residency Program at the University of Michigan. He trained initially as a mathematician at Northwestern and at Stanford, went on to medical school at the University of California at San Diego, and completed his residencies both in Internal Medicine and in Occupational Medicine. I must say I was embarrassed when I met him last night and greeted him, and said what a pleasure it was to meet him, that he said, ABut Dr. Lamm, we've met before. I remember when I was a resident in Occupational Medicine and you came and gave a lecture to us. Not only that, but he even remembered what I gave my lecture on. It's a pleasure to sit down and hear your lecture.

Dr. Steven Lamm, CEOH

Thank you very much, Al. Now comes one of the most important parts of the morning session - the break. No? Wrong. Okay. Let's take two minutes and allow a stand up break here. Stretch while we bring up the discussants and changing the moderator. Tom Armstrong from the University of Michigan will now take over.

Dr. THOMAS ARMSTRONG, >University of Michigan

Okay, let's try to get started again. We will have a formal break at 10:30, at which time you'll have more than sufficient time to commiserate with your co-attendees. Before we actually ask our discussants to speak, I'd like to make a few comments about the presentations this morning. I think the presentations this morning demonstrate the importance of having models to integrate our ideas about risk factors and our observations about their relationship with health outcomes. This morning's presentations, as well as the previous presentations from yesterday, I'm sure, demonstrate the multifactorial nature of these conditions. And this often results in confusion on the part of the lay public as well as the professional community. We've all seen papers, both in the scientific journals and also in some of the non-scientific journals, to the effect that investigators discover a link between carpal tunnel syndrome and vitamin deficiencies. Or investigators discover a link between carpal tunnel syndrome and obesity. Or investigators study a link between carpal tunnel syndrome and the use of keyboards. Or investigators study a link between carpal tunnel syndrome and the use of vibrating power tools. And people will stand back and say, well, gee, what is the real cause of these disorders? And I think the thinking of most investigators in this field now is that any one of those factors in extreme level or perhaps more likely in combination with one another can be involved in the causation or the expression of musculoskeletal disorders. And, again, these models are very helpful in bringing this together. And we have to keep reminding ourselves of this. And again I think the scientific community is as guilty of this as anyone. We often get preoccupied with one exposure factor and our research gets focused on that, and consequently we tend to interpret all situations in terms of that one factor. So, again the models are useful for reality checks. Also they're very useful in the design of studies. And I think the examples that Steve Sauter and Al Franzblau just presented demonstrate that. I've found it interesting, the studies that Steve presented comparing the field study, which was really a population of convenience, versus the laboratory study where they had very controlled exposures with extremes of monitoring and also controlled levels of skill. And they found a much greater effect under those conditions than they did in the field where their exposures were left more to chance. Similarly, with the study that Al described, repetition came out very significant but, of course, the independent variable and the studied population were selected on the basis of that factor. So again, if we're really going to study these factors it's important that we make sure that we've got a full range of those variables in our experimental design. If we don't have variability in our independent variables, we can't hope to find it in our dependent variables. With that, I would like to then introduce our first discussant. Dr. Rob Radwin is a Professor of Industrial Engineering at the University of Wisconsin. He's been very involved in development of procedures for analysis of jobs. Rob has a strong background in engineering, and has used that to develop, or put special emphasis on instrumental methods. And I think he's also using a high tech presentation this morning. Are you ready to go, Rob?

Dr. ROBERT RADWIN>, University of Wisconsin

My general impressions are that exposure to physical stress is multifactorial. And it's a major factor in musculoskeletal disorders. This was made real clear in a number of the studies. And it's clear that we can recognize physical stress, such as motion, posture, force. And physical stress can be quantified in terms of its magnitude, repetition, duration and other quantities. And that there are psychosocial and work organizational factors that are important. And these were made clear in all the studies by our speakers this morning - Mr. Bettendorf, Dr. Agnew, Dr. Sauter, Dr. Franzblau. The question that I was asked to respond to is, what do we do with it? Well, we're able to recognize many problems in industrial tasks today. And we can start to measure and quantify physical stress, although with limited precision. And we can start using our knowledge about these important relationships to make some very practical decisions in the workplace. One impression that I have that I think is very important is that as scientists, we need to better communicate to practitioners, what is knowledge and what is a hypothesis? The scientists use the scientific method and test hypotheses through experimentation and through data, and develop a hypothesis from the state of a question to knowledge. And it's important to understand what's the difference between a hypothesis and what then the level of knowledge is. And I had a brilliant diagram that I would have showed you on how to do that, but let me describe what it is. You know, if we take the current state of knowledge, industry can use this knowledge to exploit it in order to solve problems as best as they can. As an engineer, I practice engineering and I use information in order to solve problems. And this is very important. We can take the state of knowledge that we have and use that to solve problems. At the same time, scientists are trying to take hypotheses and test them and discover new knowledge. And the importance of new knowledge is in order to better understand the relationship between exposure and response, such as the study that Dr. Franzblau and his colleagues have done at the University of Michigan, to better protect employees which will be important as we gain more knowledge and to make more cost effective solutions to problems in industry. And this is an iterative process and it's ongoing and continuing as we speak. As new knowledge is uncovered, we do that. Well, where do we go from here?

Well, we need exposure measurements that target specific anatomical locations. This was a point that was made clear by several speakers, and by some speakers today as well. We need a standard exposure measurement framework that's independent of any particular injury model. And the ANSI Z365 draft standard suggests a method of quantifying physical stress risk factors in terms of force, joint angle or motions, vibration, temperature, and to quantify those physical stresses in terms of their properties of magnitude, repetition, duration and recovery. And if you've seen the ANSI Z365 drafts, you would be familiar with this framework. This framework is very useful for having a standard method in which different studies can combine knowledge and information, and compare information in order to create new knowledge. We need to better exploit technology. Dr. Agnew gave a number of examples of technologies that are available for measuring physical stress and quantifying physical stress, and our laboratory has done some work in that area as well. We need to better understand risk factor interactions. And the interactions among risk factors are very important in the study that Dr. Franzblau reported. This was a study that looked particularly at repetition or at repetitive motions of the hands, but if you remember the dose-response relationship that Dr. Franzblau put up on slide, he showed a plot of dosage against the percent affected. And in order to do this we need to be able to integrate multiple factors, factors of stress, magnitude, repetition, duration, into a metric that can be plotted along that axis because this is a multidimensional, multifactorial problem. And we still need to be able to do that.

We need to better understand the effects of duration and recovery. These factors also are very important. And practitioners who do job rotations and other interventions are recognizing this. These also need to be taken into account in our exposure assessment strategies. We need to understand how to better measure and intervene in organizational risk factors, and this was made clear by a number of studies. And we need to better quantify health outcomes. And all of these things together, I believe, are what will help us advance to that level of knowledge in order for practitioners to better solve problems in the work place.

Dr. Tom Armstrong, University of Michigan

Our second discussant will be Scott Schneider from the Center to Protect Workers' Rights. Scott has done quite a bit of work concerned with ergonomics and the construction industry, and he's a certified industrial hygienist.

Mr. SCOTT SCHNEIDER>, Center to Protect Worker'>s Rights

Just for your information, the Center to Protect Workers' Rights that I work for is part of the building trade unions of the AFL-CIO. And we're working under a grant from NIOSH to study ergonomics in the construction industry. I guess my first comment on this morning's presentations was I was kind of perplexed that we spent 75% of our time talking about ergonomics of VDT work and psychosocial factors which when I look at jobs in the construction industry - I mean I know there are some psychosocial factors that influence musculoskeletal injuries in the construction industry, but that's not main problem that we're facing. When we see huge numbers of knee injuries among carpet installers, it's not because they happen to have a stressful job, which they do, but, you know, when we see that back injuries and sprains and strains are 50% higher in the construction industry than they are in other sectors, it's not because construction workers tend to complain more - if anything, they tend to complain less, and work while they're hurt because they need the job because they don't get sick days and vacation days, etc. So I felt a little bit funny trying to comment on the presentations this morning. But I think really what we're trying to ask is, can we identify risk factors, which if you have exposure to these risk factors, increases your risk of musculoskeletal disorders, or conversely, can we identify factors that if we reduce those exposures then we'll later see a reduced risk of injury. And I think the answer is, yes. I mean, there's hundreds of studies that have looked at the risk factors that are associated with musculoskeletal injuries and I think everybody's come up with a very similar list of at least physical risk factors that we know are associated with increased risk of disease. And I just want to show you two or three slides of a study that was done in Sweden. Can I have the first slide, please? In Sweden they gave out a questionnaire to 93,000 construction workers in 1989 and they asked them how often in the past year have you had back problems, for example. And they also asked them how often in the past year have you lifted heavy objects, worked while stooping, worked with hands above shoulder level and worked while kneeling. You can see here that the amount of stooping that a person did, is how often they've had back problems. And you can see that stooping is directly related toYthe amount of stooping they do isYsorry, this is how often they stooped in the last year while working, and it's directly related to the amount of back problems they have. Likewise, but not as significant, was the amount of heavy lifting they had done. But you can see that working with your hands above shoulder level or kneeling had no relationship to the number of low back disorders that they had in the last year.

Okay, if you look at knee disorders you see a direct correlation between the amount of kneeling that was done and the amount of knee disorders they had, but very little correlation between stooping, heavy lifting and working with their hands above shoulder level. And lastly we want to look at shoulder disorders. There's a very high correlation between the shoulder disorders and the amount of work with hands above shoulder level. There's also a correlation with stooping, and a slight correlation hereYincrease in risk with heavy lifting, but no correlation with kneeling. So what is this telling us? I think what it tells us is that these risk factors are significantly associated with these kinds of disorders, and that if we reduce the amount of heavy lifting or stooping or working with your hands above shoulder levels, you're going to reduce the amount of disorders that you're seeing. And I don't deny that there are psychosocial factors or non-occupational factors but clearly, if we reduce the occupational physical risk factors that they're exposed to, we're going to be able to reduce the risk of injury and reduce the number of workers that are getting hurt every day. And I think that's what we're here to do. So that's all I had to say.

Dr. Thomas Armstrong, University of Michigan

Thank you, Scott. Our last discussant is Dr. Brad Joseph. Dr. Joseph is with the Ford Motor Company and is involved in managing their corporate ergonomic program.

Dr. BRADLEY JOSEPH, Ford Motor Company

Hello. Good morning. Morning. This is a tough one for me. I usually have slides, and they told me I couldn't have them and then three people showed up with slides; Rob's - thank God they didn't work. But everybody else had slides. I couldn't believe it. Okay. There's a couple things. A lot of people from the ergonomic community, as I represent a lot of the industry folks and especially at Ford Motor Company and UAW-Ford, a lot of the folks at Ford Motor Company said these are all good things. ABut, Brad, I've got a question for you - how much, how many and how long? And I think these are good. I think these research models are good, but eventually they have got to ask those questions and get to those responses. And I think that's what we're trying to do. We started out with, I think, a good overview with some of the critical issues. I think Bob gave an excellent overview of the big picture. Sort of what we could call the 30,000 foot level looking from the airplane, although today it's kind of foggy, looking from the airplane and looking down on the earth and saying, yeah, there's a lot of issues, we have a lot of problems and we can probably separate them out into different areas. And actually they're trying to research those questions right now. It seems like some are starting to hit on them. Those are all good things. The modifiers are interesting parts of the paradigm, but we need to understand where they're going, and how much they contribute and how much we can actually intervene in those modifiers. The second area was, again, I think at about the 20,000 foot level, more getting down to the nitty gritty of the problem, and really focusing on a couple of specific issues. Dr. Agnew really talked about the observation issues, the outcome variables and other kinds of things that are very important in looking at these problems, and also the force, repetition and posture and some of the research questions specifically focus on those issues. Again I think that's really great, we've got a focus on those issues. And then we got, you know, a little bit closer on one specific issue with Dr. Sauter in talking a lot about the psychophysical side of the business and what impact that has. Again that's a very important part of the equation, how much can we affect it. And then Dr. Franzblau really focused in on some very specific variables dealing with the issue of force, frequency, posture and some of the outcome variables. And I think that was really good because it actually started looking at the dose-response relationship. I always tell my boss, this comes down to the charcoal tube for the industrial hygienist in the field. The charcoal tube for ergonomics. And I know it's not that simple, but I think it's important for us.

Let me just give you an example in industry. Somebody trying to set up a job with 80 cycles per hour, it's an automotive assembly plant. The operator has to insert 10 push pins. We're not sure of the force, but let's say they're 5 pounds each with the right hand. And they can't really reduce the forces because they could potentially have quality problems. Do we have a potential problem or not? I think these are the kinds of things this research has to get to. And I hope it gets to it fairly soon because those are the questions our folks are being asked. And then they're asking again, like we talked about yesterday, should we invest in changing that job reactively or proactively. Let's give you another example in the office, because a lot of this was office. Dealing with the issue of offices, a manager calls up and says, Aa lot of my workers in this area are starting to experience pain and numbness or starting to experience complaints - non-specific, but complaints. Do we send them all to medical first to make sure they have carpal tunnel syndrome, or whatever, and then resolve the problem? Or do we go look at the furniture, change the process or train the employees and do some of the other areas? That's a good question for us. Again, I'm looking at this as a very practical person. I made a decision not to stay in academics and go into the practical side, and it's kind of an interesting problem for us. So I'm hoping that the research does a couple things. And I think Rob touched on this. First, the research has to generate a hypothesis and come up with some models and concepts. Then we have to interpret that. Somebody has to take that next step. The research papers are great, but they need to be interpreted some way and made practical for our use in the plants so that we can use that tool in some way to assess risk and exposure. And then we can resolve problems. And I think those are where we're trying to head. And I challenge this kind of group to do that, and I think they're on the right track. But I think we've got to always keep that focus in mind for us because that's the practical or applied perspective we're coming from. Thanks.

Dr. TOM ARMSTRONG, University of Michigan

Okay, researchers, do you have any responses to the discussants? I think one the major challenges here raised by the discussants is, how do we move from the research realm to the applied realm. How do we take this body of knowledge, as Rob put it, and use that to solve problems. And then Brad framed the question to determine how many connectors you can stuff together. If we could just go down the row of presenters and get a comment on this. Maybe starting with Steve Sauter and working down the row.

Dr. STEVE SAUTER

Actually, maybe I can comment on that plus some other issues that were raised. I guess I'll just kind of address this is a general way speaking from the kind of work that we're doing. The kind of models that I've showed and then extrapolating from that, these models that I showed and my discussion of these models represented advances or thoughts about how we are beginning to understand risk for musculoskeletal disorders in a more holistic way. I think that almost regardless of the job circumstance, you need the holistic perspective. Although I agree completely with Scott that, in some environments where the ergonomic risks are very clearly demarcated, and in the study of those you can identify differences in the physical stressors, then the role of psychosocial factors is clearly reduced. But one thing I think that is happening in occupational health in general is that the field, as it is beginning to incorporate broader issues dealing with chronic disease, then outcomes are more diffuse and non-specific. And in those types of situations then the role of psychosocial factors seems to stand out more. So, the work that I discuss at NIOSH is an attempt of ours to more broadly understand risk in a holistic way. At the same time we're doing some very specific types of work that deal with the question that was raised about intervention. For example we've recently conducted studies in the laboratory looking at different types of work regimens and that may relate specifically to Brad's question. But again we use the keyboard work as kind of a model simply because it's relevant, but it's also something that can be easily done in the laboratory. And we've actually been able in that situation to develop in the laboratory rest break regimens, which consist of frequent rest pauses that have resulted in reduced stress in workers, and at the same time reduced musculoskeletal problems. Interestingly enough, when we've done this is the laboratory workers actually are working less time at the job, but we've found that their total output is equal to workers who don't have that frequent a rest schedule. We've now taken that into the field and tested it in several large organizations and looked prospectively at workers working under these different regimens for several months. And we've essentially found the same thing there. So I don't know whether that's an ergonomic intervention or a psychosocial intervention. Repetition, as I said earlier, repetition is almost totally confounded in terms of the ergonomic and the psychosocial attributes. ButYwell, maybe I'll just stop there.

Dr. ARMSTRONG: Bob Bettendorf.

Mr. BOB BETTENDORF

Yes, I'd like to make a couple comments. One, that I absolutely agree with the discussants that the challenge is to get research that's very, very practical and basically the words that we used here were the same words that have been used in almost every one of our committee meetings over the last year. And I think it's important for us, one, to look at things like our framework, which we really put together as a way of looking at this thing in a total context in the way of communicating its complexity. But now I think, our activities are really directed towards very specific research. Again, our committee is directed towards the office. We want to answer questions like, should we or should we not use armrests when you're doing keying operations? Where should we place the monitors? Should it be here, here or down below? And we're trying very much to get down to the nitty gritty level, because I think that's what management really wants is the answers to what should I do, and why should I do it? And I absolutely agree with that comment. And in our group we've been trying very hard to focus our activities specifically in that direction.

Dr. ARMSTRONG: Al Franzblau.

Dr. AL FRANZBLAU

Well I'm going to sort of dovetail a little bit with some of the comments that have been made about the need for more practical research and some better research to more carefully delineate some of the other issues that haven't been necessarily addressed as well. For example, the study that I presented this morning focused heavily on repetition and had less ability to discriminate the impact of some other factors that may be concern. But that was part of the study design. And what that says to me is we need other studies to provide an opportunity to focus on some of these other factors. I've been doing this sort of work for about six or seven years now and I anticipate I'll be doing it for a few more years. And our approach has been an epidemiological approach rather than a laboratory approach. And epidemiology is by definition an observational science. And that means we have to try locations where we can make such observations. We have to have access. And one of the pleas I want to make particularly to many of the members of this audience who are from industry is, we need access. Researchers need the opportunity to have access to cohorts of workers or else you're never going to have decent studies done. You're going to be arguing for years about the same incomplete results or hazy results. And these are issues which can be addressed. These are issues which are scientifically approachable, and we have the methodologies to do it, but we need access. We need a lot of other things also. We need funding from the government and other places, we need a team to do it. But you know the one thing that you can control is the access. And when credible researchers come knocking on your door, try to listen to them. That's the one plea that I would make.

Dr. JACKIE AGNEW

I agree entirely with what's been said. It's always hard to be the last person to answer the question. But particularly with what Al said about access. I think all of us have encountered the problem of trying to conduct a well thought out, well planned study and sometimes a well funded study, only to find that the doors are closed and we can't get our data. I would like to stress that in my presentation I did talk about consistency of studies and study taxonomy. I think those are some of issues we have to grapple with sometimes before we share our information, our findings, with workplace management and with workers. And I think one of the things that I stressed also was the importance of developing a taxonomy of jobs. That really is something we need to be able to standardize in order to communicate. And communication is where I think all this is not happening. I also picked up one other thing that was mentioned by the discussants, and that was, we not only need to communicate with the workplace but we need to communicate with clinicians. And I think several of you out there are clinicians. We need to find ways to build bridges there and clear up some of the inconsistencies that are occurring.

Dr. ROB RADWIN

I'd just like to make a comment in response to Bob Bettendorf's question about monitor placement and some of the solutions to practical problems which are very important. And these practical questions can help provide immediate short-term solutions to problems. But it's equally important to generate fundamental knowledge. And we can't just stop at the practical answers because we can only get so far with some of the practical questions like some of the issues that were discussed earlier, for example how to locate keyboards and place monitors. The more fundamental studies will yield more powerful results, more cost effective solutions and solutions that will better protect employees. And these are only going to come from the much more detailed studies that look at the more fundamental scientific questions. And so research I think is important for both practical purposes and for the generation of knowledge. And as I mentioned in my comment, it's an iterative process. New knowledge creates new practical solutions and it keeps going on and on.

Dr. ARMSTRONG

Hopefully basic research and practical solutions are not incompatible with one another. Okay, at this point we'll open it up for questions from the audience. We ask that you hold your questions to one minute. And I guess we'll start over there on the left or my right, and move across the room to the left.

Mr. Eric Frumin: Eric Frumin, UNITE. Dr. Franzblau, your results show the influence of wrist size anthropometry which was sort of up there along with repetition in some of the results. Where are we at with that factor? How important is it that I can hear the recommendations from the screening of workers based on wrist size, you know echoing through the hall and the minds of some?

Dr. AL FRANZBLAU: I suppose there might be some very simple solutions there, which I'm not advocating. I don't think it's any surprise that anthropometry is a significant covariate in some of these models. There's nothing new about that. Other researchers and other circumstances using even different methodologies have come up with roughly analogous results. I mean, it's there, and I think it's been shown before. I'm not sure what your question is. Can you clarify what you're asking?

Mr. Frumin: How important is it for prevention purposes as a risk factor. Are we looking to control it?

Dr. FRANZBLAU: Well, I haven't yet discovered a way to alter people's wrist size.

Mr. Frumin: No, but you can screen them out of the population then, but I've seen that recommended by a number of Y

Dr. FRANZBLAU: Well, I've seen a lot of things recommended that I think are despicable, and maybe that's one of them. I don't think that that's necessarily an appropriate approach.

Mr. Frumin: Is there any payoff then based upon the wrist factor results that you've seen?

Dr. FRANZBLAU: Well, this was a cross sectional study, so in terms of payoff, you're sort of suggesting a prospective analysis of something. I can't directly address that. But what I can say from the model is the model included anthropometry and demographic factors and ergonomic factors, and even with simultaneous adjustment for those factors, which is what these types of models do, the ergonomic variables are still important. Which means regardless of what your wrist size happens to be, you have the same risk related to that ergonomic exposure. So I get the sense that's what you're fishing for, but, I sort of took that for granted because I work with these models all the time. Maybe that needs to be stated.

Mr. Frumin: It does.

Dr. FRANZBLAU: Okay.

Mr. John Parker: Yes, John Parker, Local 600 Tool & Die. I had a question for Dr. Sauter talking about psychological factors in injuries. And although in ergonomics we like to say that we are proactive when a lot of times we're just reactive and react to the problems. What I wanted to say is a lot of the workers are suffering out there with these problems and don't actually like to have them reported because . . . we have something in our society called fierce individuality. And mostly everybody who is injured on job has to go and get it reported. He shows up with this bandage or whatever it is on his wrist, and everybody thinks automatically he's a slacker. And I see that more and more on the floor. A lot of people are stressed out, trying to report these injuries, and they'd rather just not do it. So they put it off and off until there's obviously a trip to a hospital or they're off work for a long length of time where it could be taken care of in just a matter of a short length of time. Also I would like to put that they talk about opening doors - is there any research in that, in trying to get the workers and people on those jobs to be more open? As far as reporting of injuries and that?

Dr. STEVE SAUTER: Well I think that it's often a logical result of some kinds of improvements that can be made in safety programs in companies. For example, I think that type of more open reporting and not fearful reporting will follow, for example, from a program that has more of a management/labor participatory flavor to it.

Mr. Parker: See, a lot of people suffer from a fear of the future. You know, we're inundated to all this in the daily press and news, people being laid off, fired. And I think a lot of this is put off because of injury reporting is put off because they're afraid if they do report it that they're going to end up beingYhowever they put in their mind that it's not going to happen, they think right away they're going to fired or laid off.

Dr. STEVE LAMM: I'd like to respond to part of that. I think we're going to see changes in methodologies for reporting that I think may influence that. As an example, I have a study going on in explosives plants where one of the issues is the people developing blood pressure shifts over time. Part of the program there is that the workers take their blood pressure at the beginning of the shift and at the end of shift and record this into the computer. And about the same time that they record is they record what any adverse circumstances have occurred during the day. We are finding with this system that we're getting a lot of ergonomic and other, quote, the small issues that are occurring, reporting there and are able to intervene early before a big commotion is made about it. That's an example of the type of change of technology that I think we'll be able to assist you with here.

Dr. ARMSTRONG: Dr. Franzblau, do you have anything to say about reporting?

Dr. FRANZBLAU: Um, I'm not sure what you're thinking right now. But, okay.

Dr. ARMSTRONG: Why don't we move on then. Sue Rogers.

Dr. Sue Rogers: Sue Rogers, consultant in ergonomics from Rochester, New York. As a practitioner and a researcher in the past, let me request one thing for those of you who are doing research and that is related to taking repetition as a single factor instead of a multiple factor. Rob referred to this in terms of having both the work time and the recovery time within that cycle identified as well as the repetition rate. I know that Tom's published recently in this area of combining those factors. But what I find is people monitor fatigue, they don't monitor repetition. And fatigue is a combination of how long that effort goes, how much time between efforts, and total effort time as well as the repetition frequency. And, I wondered if Dr. Franzblau could tell us if in his study if the length of the effort time within each of those cycles, repetitious cycles, was under 3 to 5 seconds, or whether some of them were longer numbers. If we could characterize that work recovery within the cycle of repetition.

Dr. AL FRANZBLAU: Actually, I think Dr. Armstrong could give a better answer to this question since he was in charge of evaluating these jobs and applying that methodology.

Dr. Rogers: I just want to make one comment related to Steve's comment. This determines that control issue. How much control you have over the way you do your work and that determines whether you can live with a repetitive job or not.

Dr. TOM ARMSTRONG: I'm not sure I completely understand your question. You're really saying that the duration of the exertion and the duration of the recovery time are both important aspects of repetition, and those are both evaluated in the repetition metric that was used in the study.

Dr. Rogers: What about the repetition rate of 6 per minute, where each repetition is 2 seconds and I have plenty of recovery time during that period of the 1 minute.

Dr. ARMSTRONG: That's right. Then that would probably come out as a low repetition job.

Dr. Rogers: But at 6 per minute, and you defined your repetition rate as 6 per minute, as high.

Dr. ARMSTRONG: No. It's not based upon frequency of exertion. It's really based upon how busy the hand is. You can have a long cycle time and somebody can be doing a lot of repetition within that cycle, and it's a high repetition job. Where as you can have a short cycle time job, where somebody drops something into a machine and then they're waiting.

Dr. Rogers: Well, maybe this cycles back to our language issue which we talked about yesterday. Repetition to me is efforts per minute. I think unless we define the time for effort, we are going to have confusion on that point.

Dr. ARMSTRONG: I don't disagree with the concept your promoting here. The problem is, is that when you look at most jobs in industry, I think as you well know, they often lack discreteness in that way. It's very convenient in a laboratory study to characterize the job as a series of step functions where you've got exertion at a fixed rate, recovery with no exertion and so forth. But the reality is that when you look at these you find that the jobs are more of a continuum to that. So consequently we've moved more towards a system of rating jobs and that's described in a fair amount of detail I think in the April issue of the American Industrial Hygiene Association Journal.

Dr. Rogers: Okay. I guess maybe we ought to have some definition then in the practitioners literature about this.

Dr. ROB RADWIN: I'd like to respond to that. In the ANSI Z365, there is a framework that describes what Dr. Rogers is mentioning, and that is to look at the physical stresses such as motion and to characterize motion by its magnitude as being one property, duration being another property, repetition and recovery as independent properties. And the question then is how do you combine those into a metric that represents dose. And this study that Dr. Franzblau and Dr. Armstrong describe, that integration of those factors are done by the observer, in my opinion. And that although those factors are being taken into account by the observer and integrating them into a metric rather than using some analytical function to do that.

Dr. Rogers: It is possible, I guess in my experience, to measure and to do it metrically.

Ms. Peg Seminario: Peg Seminario from the AFL-CIO. I want to follow-up on the question that Brad Joseph asked of the presenters because I'm not sure that is was actually addressed. And that has to do with, given the research that you folks have been conducting in identifying a variety of factors that indeed contribute to musculoskeletal disorders, not only what do we need to do in additional research - and I think each of you laid out the additional areas that we need to explore. And I'm not disagreeing with that. But based upon what we have learned and what we now know, what kind of interventions can be make now? And, again, coming back and moving from science issues to some of the intervention questions and the public policy issues that are in front of us right now as to what steps can we take now given the knowledge base that we currently have in intervening, in reducing risks of exposures to those factors which contribute to musculoskeletal disorders, and what steps can be taken with respect to government action in this area? And I would just like the panelists, not directed to anyone in particular, to address this issue based upon your research and what you think we know now.

Dr. ARMSTRONG:

Can we get some quick comments from the panelists? Maybe starting with Dr. Sauter and then just quickly going down the line?

Dr. STEVE SAUTER: I have got to remember where to sit the next time. Well, since my presentation had to do principally with psychosocial factors, I'll just deal with that. And you know there have been a huge array of psychosocial factors identified as possibly involved in the etiology of musculoskeletal disorders. But some of them repeatedly show up in study after study after study. There is unfortunately a dirth of interventions that have been attempted in this area. Interventions are very difficult to do. But earlier I alluded to some that we are doing. Well, let me go back to those factors that do show up and those factors probably point to areas where we can intervene. Both in the Baumer's review and in our own review of the literature, factors like time pressure and demands consistently appear as risk factors for musculoskeletal disorders. Both in the office environment and in other environments. What I am not really sure about is the extent to which those represent real psychosocial stresses or whether the psychosocial stresses attached can be separated from the physical stresses. Other factors show up like controllability, seems to consistently show up which argues for participatory efforts. So for example right now our branch is funding some work that involves more participatory efforts in safety and health committees, etc., and that work which has not been reported extensively yet seems to be leading towards a reduction in musculoskeletal disorders in hospital environments. Other things that consistently show up in the psychosocial literature are things like having a supportive environment to work in, organizational support or supervisory support, again pointing to at least areas of focus within an organization to help to intervene and minimize problems. So those are, in the psychosocial domain, those are three or four areas where intervention is probably warranted based upon the literature. And in one or two of those where some intervention research is already underway.

Dr. ARMSTRONG: Bob Bettendorf, do you have anything to add?

Mr. BOB BETTENDORF: Again, speaking about the office, I think we've come a long way in the last four or five years in terms of how to define an ergonomic program, what are the right steps to take, what are some of the ergonomic risk factors. I think we have not enough knowledge in terms of how effective these are. I could tell you as a practitioner that they are effective, but I really can't quantify that. The second part of Peg's question is really one that I am not going to try to answer because our committee made the decision four or five years ago that we're not going to get involved in the, 'should we mandate these things or should they be done voluntarily?' But I think from the standpoint of the office, a lot of companies are already starting to address these problems and to put ergonomic programs in place.

Dr. ARMSTRONG: Dr. Franzblau?

Dr. AL FRANZBLAU: I think from the nature of this conference and from the nature of the comments, there are a lot of things which I think we know, as Bob was alluding to. And there are a number of things which are more the 'gray zone.' There are issues of dose-response, which I think our study helped to better define in some circumstances. And so in terms of getting down to the nitty gritty of regulation, I think it's going to be tough to try to get down into that gray zone. But I think there's some fairly obvious things. I mean, you can walk into an environment and you can look at something, and you go, 'oh, well gee, we can do better than that.' And I think there's some fairly high points that are more easily recognized that I think could be addressed with today's knowledge base. Where you draw the line, there's going to be some disagreement there. But I think there are certainly some things which could be addressed.

Dr. ARMSTRONG: Jackie?

Dr. JACKIE AGNEW: I think Peg's question indicates that we dodged the question the first time. I'm going to say with regard to policy approaches, we do need some more concrete information to be able to share. And that means stronger support for research so that we have good information to share. I do feel like there are some pretty obvious findings that have been mentioned by all the folks on this panel before me that can be incorporated into workplaces to make them safer for the worker. But, at the same time, we do need more research. NIOSH has recognized this by including musculoskeletal problems in the National Occupational Research Agenda, NORA, that recently came out. And we all agree, I think, that we need to get on with intervention studies, longitudinal studies, to see what really does work in the workplace.

Dr. TOM ARMSTRONG: I'd like to just add a comment to this as well. Not only can we intervene with the information that's available, but people are intervening. I've been in this business long enough to have visited offices where people are doing keyboard data entry work where they're basically sitting around at tables that have no adjustability. They're sitting in something equivalent to a wicker chair, working on a computer that does not have a detachable keyboard and doing heads-down data entry for eight hours a day. We don't see those kind of work stations in most office settings anymore. By and large, we do see computers with detachable keyboards, where the keyboards are now adjustable. We see adjustable seating in those situations and a variety of document holders and wrist pads and so forth for people to utilize. It was only ten years ago when it was very difficult to get something as simple as a workbench that was adjustable in height, and that was solid enough to be used in industrial applications. I had the opportunity to tour one of Brad's facilities a few weeks ago, and was very impressed with some of the changes that we saw in that plant versus a plant of ten years ago where people were using hand-held power tools that are now supported with articulating arms and a variety of torque control mechanisms and jigs and fixtures that support work, articulating arms to insert spare tires and seats and so forth. So I think the reality is that people are making changes based upon the data available, that there has been a response from the industrial sectors and we're moving in the right direction. I suppose the 64 dollar question is in terms of what has been the impact of that on worker health? As you know the experts are still arguing about what are the health issues that we're trying to measure. And, should we delay these kinds of interventions before we have definitive proof. And as we move forward to implement, can we implement them in a way in which they can be evaluated? And that goes back to build on some of the pleas from the panelists about the need to have access to workplaces and to evaluate these things as they're done. With that, we're actually 3 minutes into our break. And we know how popular breaks are. And so I guess I'll turn the microphone over to David Felinski for a few final comments.

Mr. DAVE FELINSKI, AAMA

For those folks that were still standing in line waiting to ask questions, if you would like to submit your questions in writing to me and just indicate which, either speaker or discussant you would like your question directed to, we'll try to make sure that those questions and answers are published in the proceedings.

QUESTIONS SUBMITTED IN WRITING FROM THE AUDIENCE:

To: Dr. Al Franzblau

Submitted by: Dr. Gary Franklin, Washington State Dept. of Labor & Industries

The definition of median mononeuropathy by abnormality ($0.5 msec.) of the median-ulnar sensory latency difference may be somewhat problematic, in that this particular test depends on the function of two different nerves. Did you run the analyses using only the distal median sensory latency (14 cm or 8 cm), rather than the median-ulnar latency difference as the dependent variable (alone or with a positive hand pain diagram)?

To: Dr. Al Franzblau

Submitted by: Dr. Ron Schopper, CSERIAC

Dr. Sauter spoke of psychosocial factors and their importance in the VDT (like physical demand) environment. Dr. Franzblau indicated that they had included some psycho-social questions in their assessments -- but failed to comment on their impact. By inference, there was none.

Is it true (as was suggested / intimated by Dr. Radwin) that psychosocial issues have little importance in the work environment which poses a higher physical demand?

If yes, what is the literature that pertains?

Has it been reviewed and documented anywhere? (If yes, where?)

To: Dr. Tom Armstrong

Submitted by: Pat Bertsche, Ohio State University

The conference is focusing on major science and policy issues that are confronting the ergonomics community. In the opening session of the conference, the Ergonomics Coalition representative stated that back in 1993, the ANSI Z365 Committee stated that there is not enough science in the area to develop a standard, whether it be an ANSI standard or other standard.

Is this true?

Was it true in 1993?

What about 1997?

[At the time of publication of these Proceedings, neither of the individuals to whom these questions were directed had provided any response.]