NOTE: This document is provided for historical purposes only.
Question and Answer Session
DR. PEACOCK: Well, that is probably a record. One ex-university professor and two university professors finished 15 minutes ahead of time. There will be 15 minutes for questions for anybody who has questions. We said some very different things and some contradictory things I think this afternoon. And so, one would hope that there might be some questions.
Q : I have two questions and they're for Bill Marras. I enjoyed your presentation and the multimedia associated with it. The first question is the problems that I've seen in the warehouse industry have a lot to do with timing issues and time standards. And I was wondering whether or not you had addressed that portion of the research?
DR. MARRAS: We have considered that a constant in this. I know what you're talking about. A lot of times these people are really pushed by performance standards. We observed that warehouses work people at 125 boxes per hour. We did not look at this as a variable in this initial study.
Q : Do you have any ideas on how you would perform that research?
DR. MARRAS: Same thing except pace people at different times and see how the muscle recruitment patterns change and what that does to the different loadings of the spine.
Q : The second question that I have is the use of EMG analysis in general. You appear very well versed in the use of EMG analysis in research, but in looking at this, you make it seem very simple with all of your gadgets and your programs. But, indeed, I would not recommend the use of EMG research unless it's performed by someone such as yourself in a university site. Rob Radwin has excellent materials and equipment as well, but I've seen a great number of consultants, I shouldn't say a great number, but a number of consultants use EMG analysis in a way that provides results, but not results that might have the integrity that you would want them to.
DR. MARRAS: That's an excellent observation, and I completely endorse your observation. If there's one measure that's probably misused more than anything, even in the literature, is probably EMG. And I would not encourage people to go out and just apply EMG's randomly. As you probably know, you have to do a lot of calibration. You have to do maximum strength efforts, make sure the people don't fatigue and make all kinds of adjustments to make some sense out of it. So that's an excellent point.
DR. RADWIN: That's also another example of how universities might be utilized for accessing advanced technologies that are not usually routine/available in industry or by some consultants.
Q: Larry Bullock, Proctor and Gamble. I'm struggling with how to set lifting guidelines for our company. In other words, basically, I've been telling people, go use the NIOSH lifting equation and all your problems will be solved. People want me to set up some sort of company-wide number that you shall not lift more than this many pounds. Do you have any advice to give to companies that are struggling with how to set weight limits that are simple yet meaningful?
MR. PEACOCK: I will address this question and discuss the first question that was asked of Bill about frequency. The problem that we face and which I suspect is the same as you is that the person who makes the decision about the size or the weight of the box is a product engineer. The person who designs a pallet or a lifting device is a manufacturing engineer. The person who designs how many times a minute somebody should lift it is an industrial engineer. So three different people need communication from this ergonomist.
One other part of that story is that the person who designs the weight of the box did so five years ago. Whereas, the industrial engineer has a shorter lead time to effect the frequency issue. If you don't have a job to look at, that is, if you are looking five years ahead, you don't know how often the thing is going to be lifted or under what conditions it's going to be lifted.
The process that we use in General Motors is to make certain assumptions about conditions and frequencies and draw a line in the sand on weight. Once you've got a line on weight, we then will draw a line in the sand as to whether to have an assist. Finally, we draw a line in the sand about frequency. We have to draw these different lines in the sand that apply to different engineering functions. Bill or Robert, would you like to comment?
DR. MARRAS: Yeah, my response would be it goes back to something Brian said earlier which is, it depends on what you do. And I know that's not what you want to hear, but that's the truth. Ergonomics is situation specific. You don't just go out and buy ergonomic tools and think you've done ergonomics, because what's called an ergonomic tool in a bad situation is bad ergonomics.
It's the right tool in the right place at the right time. So if you're going to force me to give you one answer, I'd say don't use your hands and everything's fine. But then you won't get the task done.
Q: Question for you, Brian. My name is Ed Fredericks. I'm an industrial hygienist with Michigan OSHA. The corporate-wide settlement between GM, UAW and OSHA is winding down, and I know from our experience, we see plants that have done very well and then plants that have not done so well. Are you a part of or are you aware of any type of report card kind of thing that GM, UAW or OSHA will be producing as the agreement wears down?
MR. PEACOCK: No, I cannot address that question. I am not part of that joint activity. I exist in the engineering function which deals mainly with pro-active design, and you're referring to a joint UAW-GM-OSHA reactive program. At the moment, the discussion of its continuance or the report card is up in the air. So I'm afraid I can't answer that question.
Q: Okay. And one for Bill. I know that we need quantitative analysis in litigation and in workers' comp and things, but what you just portrayed up there I would say would be intuitively evident to those who go into workplaces and look at workers working and talk to workers who are doing the work.
DR. MARRAS: There are situations where the cost is high in terms of injury rates or dollar costs, or whatever, where it makes a lot of sense to do a quantitative analysis because you don't want to be wrong. And that's where you use these types of assessment tools.
Q: Thank you.
Q: Hi, I'm Mike Fleming with Sara Lee, and my question is for anyone on the panel who'd like to jump on it. Lift truck manufacturers for the last several years have addressed ergonomics issues. The specific piece of equipment I'm thinking about is a narrow aisle equipment. The Crowns, the Heisters, the Yales have done a lot of work with ergonomics and human factors inside the operator compartment. The particular affect I'm speaking to is the single function control. Heister, within the last year, has almost been forced to go do this because of pressures from customers.
Have any of you had any experience in helping to quantify or evaluate or are you aware of any comprehensive studies that have been done that are in the literature that I could go to help find these answers?
DR. RADWIN: I think you hit the nail on the head. There is a great deal of literature on manual control design. Ergonomics, as Brian pointed out and Bill too, is much greater than just the prevention of work related musculoskeletal disorders. It involves the enhancement of operator performance and many other factors involved with safety and the use of controllers on forklifts or construction vehicles for example. We've worked with construction vehicle manufacturers on these kinds of controllers. Some of the methodologies that I showed you earlier describe how you might quantify and study repetitive motion force, the postures associated with the use of different controllers. There's very little published on these kinds of controllers specifically with regard to physical stress as opposed to manual performance and the ability for the operator to accurately and quickly use the vehicle.
Q: Chuck Taylor, Association of American Railroads. When we talked to our equipment and tool designers in our industry, quite often when we discuss with them why they don't give us a more environmentally and friendly product line, typically, the response we get is well, it's because it costs so much more than the current product line, and our customers aren't willing to pay for that cost.
Well, setting aside the issue of whether or not the customers ought to pay that premium, based on considerations of total life cycle costs, has it been your experience that, indeed, if you're going to take that extra effort with regard to a more ergonomically designed product, that it is going to substantially increase the cost of that product?
MR. PEACOCK: I think I can answer that question. We're continually faced with that problem. We recommend a design change, and then the people who have been designing that equipment in the past say, no, it'll cost too much or who will pay for it? It's always an issue. It might be handles or controllers, or it may be weight or welding machine design. We try to draw some reasonable lines in the sand that we give to the suppliers, and then we argue it out around the table.
One of our big activities is, in fact, communication with suppliers for equipment and tool design, and it's often a very difficult battle. But cost is always an argument, and there are a lot of people at this conference are discussing the costing of ergonomics.
DR. MARRAS: In my experience, the cost is only high if you try and retrofit. If you consider the design initially when you're first talking about building the tool or whatever it is, usually it's not much more than, and if anything, there's no cost at all most of the time just by doing it right in the first place. But just like in manufacturing processes and everything, if you discover you've got a problem too late and you go back and try to retrofit it, that's where the high cost comes in.
And, you know, I've had some well-known tool manufacturers talk to me about a lot of these issues, and what they tell me is that the cost is really minimal for changing the tool. But they feel it's a marketing point, and so, they'll charge you 15 percent more just to change the color to yellow and label it ergonomics. So I'm not sure it's a real cost.
Q: I'm Monica Steele from Abbott Laboratories, and this is for anyone. Similar to the gentleman asking about a one number, I've been asked to give one number. But fortunately, I'm giving this to design engineers. We manufacture diagnostic equipment, some of which are the size of small Volkswagens, and I'm trying to minimize the risk of having a 120 pound power supply being handled from six inches off the floor by a service engineer in the field. So I can handle manufacturability, but service ability is my worst case.
I won't give them just one number obviously. I've tried giving them regional numbers, you know, knuckle, waist and shoulder numbers, but that's not satisfactory to them mostly because the numbers are so low for low regions. I'm wondering if there is one tool that you would give a mechanical design engineer, be it one of the NIOSH models or a bio-mechanical model. Which it might it be that you would have the most confidence in? Not only the results, but given the fact that these engineers may not be trained in ergonomics and may not use it properly.
In other words, which tool is most likely for them to not make a drastic error and to come out with some reasonable results? Or do you think I ought to stand firm on some numbers that I've done the analysis?
DR. MARRAS: Well, I guess the question is how important is it to be a 100 percent right? Is the ball park good enough?
Q: I think in order to improve the situation we have today, a ball park is a wonderful first step, yes.
DR. MARRAS: What I would recommend is just base it on the very simple concept of moments. If it's so far away and you can handle so much weight. If it's so high, you couldn't handle so much weight. If it's so low, you can handle so much weight. And that's probably the simplest and easiest thing to do. Keep it simple.
Q: So given certain moments they can easily calculate the moment, where would I find, you know, the guidelines as far as what numbers?
DR. MARRAS: Okay. There are a lot of sources for that. For example, if you look at the first phase of the OSHA Standard, those are some ball park things. The part that enters you into the more advanced NIOSH analyses. That's probably the simplest way you could do it.
Q: Okay.
DR. MARRAS: There are a lot of lifting calculators out there, computer programs. There's all kinds of ways to get those numbers.
Q: Deal with the moments only. Okay. Thank you.
MR. PEACOCK: One answer to that question is that we're forever asking questions of that nature, and the approach that we use is a consensus of experts to come up with the number.
I think I've got to draw this to a close. But before I draw it to a close, I've got to thank Jim McGlothlin from NIOSH in putting this session together and got us all to come to talk. Again, thank you very much, Jim. And thank you all for coming.
Whereupon, the Product Design session was concluded.
