ASSE 2002


From Research To Reality

Liberty Mutual Research Center for Safety & Health

 Part I – Introduction

 Tom B. Leamon, Ph.D., CPE

Satisfying the need of the Professional Safety Engineer for effective, and appropriate tools is a critical criterion for the development process, From Research to Reality .  In many circumstances the process is unorganized and rather haphazard, as individual university researchers respond to requests for proposals by various agencies, crafting their submissions based upon their current expertise and the resources of the particular institution, including the particular intellectual capital of the institution.  In part, the process at Liberty Mutual Research Center is aligned rather differently and anticipates a priori, a subsequent function committed to turning the research findings and the resultant knowledge base into products, be they informational, software or hardware.  Such products will enable safety engineers to design and manage safer work places for the American worker.  This process has two necessary components, not found in research centers, the existence of a large group of Loss Prevention Consultants, highly analogous to the individual safety engineers working throughout industry, and the essential professional interface between the research domain and these practicing engineers.  This afternoon the research activities will be discussed by Dr. Vincent Ciriello and my colleague, Mr. Wayne Maynard, will describe the way this knowledge base is brought to bear upon workplace design and management.  By design, Mr. Maynard s function requires credentials including being a Certified Safety Professional and having a wide experience as a Safety Engineer and that he is located within the Research environment, participating as an advisor to, and in some cases as a contributor to the research program itself.

While we take as axiomatic our commitment to From Research to Reality, this commitment might be even more appropriately described  as:  from reality to research to reality .  The first component in the process is to determine what should be researched, bearing in mind our long term commitment to making a difference in the reality of the American workplace.

It has been apparent that historically, federal funding for research in areas of safety has not necessarily been allocated to the most significant problems in industry.  As more recent history has shown, concerns in the media can sometimes cause a diversion of scarce resources away from the most significant problems.  In an attempt to determine the areas for research, the sources of loss and the economic burden borne by the nation seems an appropriate metric for setting priorities.  In daily practice, management is faced with conflicting demands: from advocacy  organizations for particular interventions, such as groups concerned with latex allergies or repetitive trauma of the upper extremity.  It may be buffeted by media attention, possibly involving horrific individual events, or by political controversy such as that generated by the proposed OSHA ergonomic standards and by Labor s own perception of these sources of concern.  In many cases the perception of the risk manager is amalgam of these information sources which, if not congruent with the actual source of loss, may divert resources from the real issues.  Consequently the risk manager, in trying to balance these issues may respond differently to the safety professional, who is likely to focus entirely upon the most effective way of reducing accidents and thus the resultant injuries and the associated costs, both personal and financial.

In an effort to determine the corporate perception of what the major safety issues were in American workplaces, two hundred senior risk managers were interviewed in depth.  The interview was based upon a questionnaire developed at the Research Center and analyzed subsequently by the scientists at the Center.  The managers were asked to identify the more serious safety issues facing their corporation selecting from a list but with the opportunity to add other factors which might be specific to their business.  These results were aggregated and reported in Table 1. as the Risk Management Survey.

Table 1.  Liberty Mutual Executive Survey of Workplace Safety – 

Top Ten Accident Causes Ranked by Executive Concern

Repetitive Motion 1
Overexertion – Injuries from lifting, lowering, pushing or pulling 2
Highway Accidents 3
Bodily Reaction – Injuries resulting from bending, standing, reaching but not  including slipping and tripping without falling 4
Falls (to lower level) 5
Caught in or compressed by equipment 6
Falls (same level) 7
Struck by object 8
Contact with temperature extremes 9
Being struck against an object 10

In general their concerns matched reasonably well the sources of loss faced by our customers with two major exceptions.  Both these reflections may reflect a societal concern rather than a business view of these issues.  Repetitive motion claims the number one position at the top of the list and the clearly pedestrian problem of slipping on the same level, although recognized as significant, was placed at position 7.  These rankings do not correlate with multiple studies carried out at the Center.

In the development of the Liberty Mutual Workplace Safety Index a further analysis was carried out to identify the true burden of various events.  Basically, claims data provided an estimate of the average cost of various types of claims, which were then matched, through a crosswalk process, with the incidence data generated by the Bureau of Labor Statistics.  Given the average cost and the national number of occurrences we could rank the causes and identify the top ten, workers compensation costs.

For various technical reasons, the aggregate of our estimate was somewhat less than that produced by the National Academy of Social Insurance and thus the ratio of the top ten were applied to the NASI value to determine the true costs to the American business which is shown in Table 2.

Table 2.

SWILiberty Mutual Workplace Safety Index

Strikingly, repetitive trauma is much less of a problem than perceived by risk managers, while the major losses associated with slipping on the same level are clearly evident in this data.

While such an approach establishes the financial burden from these loss sources, it may also rank the personal burden on the workforce.  Workers compensation costs can serve as a reasonable surrogate for severity, in that the length of time lost from work and the extensiveness of medical treatment are reflected in the dollar costs.

This astronomic cost identified in Table 2. however, is only the insured portion of the actual losses faced by business.  The Safety Profession has long grappled with the skepticism of Management to accept estimates of the ratio of insured to uninsured costs.  While we did not determine the ratio directly, the Risk Managers were also asked to make a best professional judgement of the ratio of insured to uninsured costs of accidents for their industry.  As expected the estimates varied, but the large majority fell in the range of 3 to 5 times of insured costs.

Thus, maybe the best estimate available of the burden carried by the American business community to accommodate injury and disease in the workplace is that it lies between one hundred fifty five and two hundred thirty two billion dollars.  There is a huge opportunity for safety engineers to impact these losses-given appropriate tools.

With both the scope and the relative significance of the various injuries identified, research programs can be designed to develop fundamental understanding.  As well as applied solutions, to these problems thus focusing the very scarce research resources of the nation in those areas of most significance.  Such an approach is followed at the Liberty Mutual Research Center and the resulting research is described in the second paper by Dr. Ciriello.  Additionally, this focusing on the real issues, enables a cadre of researchers with focused and relevant skills and training to be developed, allowing a problem oriented approach, rather than an approach in which particular researchers determine which part of a problem matches their skillset.

Thus, while we are confident in developing a research stream and committing significant resources to investigating these tasks we also need an effort to seek to understand emerging risks and exposures which, in due course, may present the opportunity for future product development. The significance of these emerging risks however must be set against the fact the top four or five topics identified in the Liberty Mutual Index are in fact remarkably robust across industries and over time.  In this group there has been little change in the relative significance over the past decade. Moreover, and quite surprisingly, these types of losses occur across a very wide range of industries.  The specific industry process risks inherent in various activities appear to change at levels below the top five or so.  Such process risks, for example in the chemical business appear to consume a larger proportion of intervention expenditures than do the garden variety problems of lifting and lowering things and slipping and falling for like most industries despite the costs of manual materials handling and falls is perhaps ten times greater than the process risk.  Clearly this is not to say that such an expense is inappropriate, for it may be that this increased level of expenditure results in the risk being lowered in contrast with our top five.  However, again it indicates that, given professional resources and products to evaluate and determine successful interventions, the potential gains by the employment of safety engineering are enormous.

Part II – Research

 Vincent M. Ciriello, Sc.D., CPE

Manual Material Handling Investigations

Eleven of our manual material handling (MMH) experiments which form the basis of our comprehensive guideline (Snook and Ciriello, 1991) used a psychophysical methodology, with measurements of oxygen consumption, heart rate, and anthropometric characteristics.  Essentially, the subject is given control of either the weight or force variable.  All other task variables such as frequency, size, height, distance, etc., are controlled by the experimenter.  The subject then monitors his or her own feelings of exertion or fatigue, and adjusts the weight or force of the object accordingly.  Details of the experimental designs used in the studies are found in the individual papers (Ciriello and Snook 1983, Ciriello et al. 1990, Ciriello et al. 1993).  The main features of the basic design, however, are given below.

Realistic tasks

The experimental tasks were made as realistic as possible.  For example, lifting tasks were dynamic lifts through a given vertical distance.  Pushing and pulling tasks were dynamic pushes through a given horizontal distance.  Test sessions lasted approximately 4 h.  Each test session usually consisted of five different 40 min tasks, separated by 10 min breaks.  When testing for the effects of duration, the same task was performed for 4 h with a 20 min break after 100 min.

Groups of three subjects participated in at least two test sessions per week for a minimum of ten weeks.


During lifting, lowering, and carrying tasks, subjects handled industrial tote boxes or cardboard boxes.  The boxes varied in length (the distance between the hands) and width (the distance away from the body).  When handles were used, they were located mid-way in the width dimension.  Each subject varied the weight of the box by adding or subtracting loose shot with a small scoop.  Welding rod was used in the larger boxes.  In an attempt to minimize visual cues, each box contained a false bottom.  The subjects were aware of the false bottom, but never knew how much shot or welding rod it contained.  The amount of weight in the false bottom was randomly varied.

A special device with a rapidly moving shelf was used to automatically lower the box after each lift, or to raise the box after each lowering task.  When the box was removed from the shelf by the subject, the shelf quickly moved to a new, predetermined position in time for the subject to place the box on the shelf.  The box was slid off the shelf, lifted (or lowered) clear of the moving shelf, and then slid back onto the shelf.  In most cases, the lifts and lowers were not truly symmetrical since some degree of body twisting was involved.  When the box was replaced on the shelf, the shelf returned to its original position.  The starting and stopping points of the shelf were adjustable.

Pushing and pulling tasks were simulated on a specially constructed treadmill.  The treadmill was powered by the subject as he or she pushed or pulled against a stationary bar.  A load cell on the stationary bar measured the horizontal force being exerted.  The subject controlled the resistance of the treadmill belt by varying the amount of electric current flowing into a magnetic particle brake geared to the rear drum of the treadmill.  All subject controls were devoid of visual cues.

All four experiments were conducted in a 3.9 m x 2.8 m x 3.0 m environmental chamber.  The dry bulb temperature was maintained at a moderated 21.0°C; relative humidity was 45%.

Industrial workers

Subjects were second-shift (evening shift) workers from local industry.  They were all given a medical examination prior to their participation in the experiments to ensure that they were in relatively good health.  A battery of 41 anthropometric measurements was taken for each subject.  Clothing was controlled by providing surgical scrub suits for all subjects.  Safety shoes with neolite heels and soles were also provided to control for variations in traction during pushing and pulling tasks.  Heart rate was monitored continuously by radio telemetry for each subject.  Instantaneous measurements of steady state oxygen consumption were obtained after subjects had selected the maximum acceptable weight or force.


Subjects were instructed to work on an incentive basis, working as hard as they could without straining themselves, or without becoming unusually tired, weakened overheated, or out of breath.  Four or five days of training sessions were provided to allow subjects to gain experience at monitoring their own feelings and adjusting object weight or force.  Subjects began with moderate frequency, short duration tasks and gradually conditioned themselves to the faster, longer tasks.

New subjects tended to accept the initial weight of the object that was given to them.  Therefore, they were encouraged to make adjustments in the weight by starting them with a very light or a very heavy weight.  To overcome adaptation effects, each manual handling task was broken up into two 20 min segments; one segment with a heavy initial weight and the other segment with a light initial weight.  There was no rest period between the two segments.  If the results of the first segment were within 15% of the second segment, the average of the two results was recorded.  Otherwise, the results were discarded and the test re-run at another time.  Similar procedures were used when testing for the effects of duration, except that eleven 20 min segments were used with a 20 min break after the fifth segment (Ciriello et al. 1990).

Each of the eleven experiments included two types of tasks: criterion tasks and variation tasks.  There were a total of seven criterion tasks (two lifting, two lowering, one pushing, one pulling, and one carrying). Each experiment investigated different variations in task frequency, height, distance, and box size.  Since it was impractical to run every subject on every possible variation task, the percentage difference from the criterion task was used to develop an adjusted mean for each variation task.  (The criterion and variation tasks were performed by the same groups of subjects.)  The standard deviation for each variation task was determined from the adjusted mean and the criterion task coefficient of variation.  The mean and standard deviation for each criterion and variation task were used with the normal distribution to determine the maximum weights and forces acceptable to 10, 25, 50, 75 and 90% of the industrial population. These data are presented in 9 tables of maximum acceptable weights and forces (Snook and Ciriello, 1991) and form the basis of our computerized task analysis program called CompuTaskII.  Further experimentation has checked the validity of some assumptions made in the 91 guideline (Ciriello et al., 1999a, Ciriello et al., 2001a, Ciriello, 2001).  Future experimentation will be guided by our recently published comprehensive MMH surveys (Ciriello and Snook, 1999, Ciriello et al., 1999b).

Repetitive Motion Investigations

The psychophysical method used for the repetitive motion studies (which began in 1989) is similar to that used in the MMH studies with some changes.  To simulate exposure time found in tasks that commonly result in cumulative trauma disorders (CTD), the task was performed in seven, 55-min segments over an 8-h day, 5 days a week, for a total of 4 weeks.  Only female subjects have been studied to date, as they represent both the majority of workers performing repetitive motion tasks and the majority of CTD cases reported.  Rather than use industrial workers, subjects were selected who have had no previous exposure to repetitive motion tasks (either occupationally or recreationally) and who had no history of current risk factors for CTDs.  Subjects were instructed to choose a maximum force that they can perform for an 8-h day without developing symptoms in the fingers, wrist, or forearm.  Different frequencies were studied on different days.  The tasks studied so far include power flexion, power extension, pinch flexion, pinch extension, ulnar deviation, pliers type task, 3 types of supinations, and a pronation task.  Six studies have been published or accepted (Snook et al. 1995, 1997, 1999, Ciriello et al, 2001b, 2001c, 2001d). Guidelines for maximum acceptable torques for the above movements have been developed and are presented in Ciriello et al, 2001b and 2001c.

Repetitive tasks often involve the use of hand held tools. Although hand tools have been refined to accommodate the needs of today, workers interactions with hand tools still pose a safety and health issues. Our human machine laboratory investigates the stresses involved in a variety of hand held tool operations. Typical findings demonstrate that poor workplace design leads to discomfort and stress and may compromise productivity as well (Dempsey et al, 2000, McGorry, 2001, McGorry et al, 2001)

Repetitive tasks investigations also encompass the research in office ergonomics. Office ergonomic intervention programs have a goal of providing a healthy and safe environment for office workers. Ergonomic intervention strategies include adjustable workstations and training in ergonomic principles of workstation design. Properly designed workstations along with knowledge of ergonomic principles should provide the worker with both lower musculoskeletal and psychophysical stress levels. Ongoing research in the office ergonomics laboratory is focused on documenting office workload and the effect of ergonomic intervention on the stress levels at specific workloads. The results of the laboratory studies will provide the essential design data for the successful implementation of office ergonomics intervention.

Slips and Falls Investigations

Experimental investigation in the area of slips and falls share a common goal of attempting to reduce occupational injuries in this area.  A multidisciplinary approach is needed to deal with the complexity of slips, trips, and falls.  The disciplines most often used are Tribology, Biomechanics and psychophysics.  In the area of tribology, we have on-going experiments in floor surface roughness, use of slipmeters, and footwear evaluations.  The key to surface roughness is to identify those surface features which indicate a friction relationship between shoe and floor surfaces.  Experimentally, this is accomplished by measuring surface profiles and extracting roughness parameters which may correlate with dynamic friction.  In the area of slipmeters, we have been very active in evaluating existing commercially available slipmeters and we also have been developing a portable slipmeter for field use.  This slipmeter has the ability to measure steady state, dynamic, and transitional friction.  The measured friction on this prototype device has correlated significantly with subjective ratings.  Slip resistance of foot wear made with common materials and measured with a variety of surface dressings will also be an ongoing activity in our experimental investigations.

In the area of Biomechanics, observed slip distance has been used as an indicator of slipperiness.  Also, slip potential can be used to quantify a potential risk in occupational condition such as exiting from a truck onto different ground conditions.  These two examples illustrate how biomechanics research has developed risk models in the safety of a computer and subsequently applied in the field.

Lastly, psychophysics has been used in our laboratory as an experimental technique whereby the test subjects choose the level of acceptable workload of pushing by responding to the slipperiness of different floors.  Experimental papers describing the variety of the research efforts summarized above have recently been presented in a special issue of Ergonomics (Chang et al, 2001a,b,c, Courtney et al, 2001a,b, Gr nqvist et al, 2001 a,b, Redfern et al, 2001) and other journals (Chang, 2001a-d, Gr nqvist et al, 2001c,d, Chang and Matz, 2001)


Chang, W.R., and Matz, S., The Slip Resistance of Common Footwear Materials Measured with Two Slipmeters Applied Ergonomics, 32:549-558, 2001.

Chang, W.R., From Research to Reality on Slips, Trips and Falls, accepted for publication in Safety Science, 2001c.

Chang, W.R., Gr nqvist, R, Leclercq, S., Myung, R., Makkonen, L., Strandberg, L., Brungraber, R., Mattke, U. and Thorpe, S., The Role of Friction in the Measurement of Slipperiness, Part 1:

Friction Mechanisms and Definitions of Test Conditions, Ergonomics, 44:13, 1217-1232, 2001a.

Chang, W.R., Gr nqvist, R., Leclercq, S., Brungraber, R, Mattke, U., Strandberg, L., Thorpe, S., Myung, R., Makkonen, L. and Courtney, T.K., The Role of Friction in the Measurement of Slipperiness, Part II:  Survey of Friction Measurement Devices, Ergonomics, 44:13, 1233-1261, 2001b.

Chang, W.R., Kim, I.J., Manning, D.P. and Bunterngchit, Y., The Role of Surface Roughness in the Measurement of Slipperiness, Ergonomics, 44:13, 1200-1216, 2001c.

Chang, W.R., The Effect of Surface Roughness and Contaminant on the Dynamic Friction of Porcelain Tile, Applied Ergonomics, 32:173-184, 2001d.

Chang, W.R., The Effects of Surface Roughness and Contaminants on the Dynamic Friction Between Porcelain Tile and Vulcanized Rubber, accepted for publication in Safety Science, 2001b.

Chang, W.R.,The Effects of Slip Criterion and Time on Friction Measurements, accepted for publication in Safety Science, 2001a.

Ciriello, V. M. ; The effects of box size, vertical distance, and height on lowering tasks. International Journal of Industrial Ergonomics, 28:61-67, 2001.

Ciriello, V. M. and Snook, S. H.;  A study of size, distance, height, and frequency effects on manual handling tasks.  Human Factors, 25:5, l983.

Ciriello, V. M. and Snook, S. H.;  Survey of manual handling tasks.  International Journal of Industrial Ergonomics, 23:149-159, l999.

Ciriello, V. M., Snook, S. H. and Hughes, G. ; Further studies of psychophysically determined maximum acceptable weights and forces. Human Factors, 35:11, 175-186, 1993.

Ciriello, V. M., Snook, S. H., Blick, A. C. and Wilkinson, P. L.;  The effects of task duration on psychophysically-determined maximum acceptable weights and forces.  Ergonomics, 33:2, 187200, 1990.

Ciriello, V.M, Webster, B.S., and Dempsey, P.; Maximum Acceptable Torques of Highly Repetitive Screw driving, Ulnar Deviation, and Hand Grip tasks for Seven Hour Work Days. American Industrial Hygiene Association Journal, accepted September 6, 2001c.

Ciriello, V.M., Bennie, K.J., Johnson, P. W., and Dennerlein, J. T. ;  Comparison of Three Psychophysical Techniques to Establish Maximum Acceptable Torques of Repetitive Ulnar Deviation. Theoretical Issues in Ergonomic Science, accepted Nov. 8, 2001d.

Ciriello, V.M., McGorry, R. W, and Martin, S. E. ; Maximum acceptable horizontal and vertical forces of dynamic pushing on high and low coefficient of friction floors.  International Journal of Industrial Ergonomics, 27:1-8, 2001a.

Ciriello, V.M., McGorry, R.W., Martin, S., and Bezverkhny, I.B.; Maximum acceptable forces of dynamic pushing: comparison of two techniques. Ergonomics, 42:1, 32-39, 1999a.

Ciriello, V.M., Snook, S.H., Hashemi, L., and Cotnam, J. Distributions of manual materials  handling task parameters.  International Journal of Industrial Ergonomics, 24:355-454,1999b.

Ciriello, V.M., Snook, S.H., Webster, B.S., and Dempsey, P.; Psychophysical study of six hand movements.  Ergonomics, 44:10, 922-936, 2001b.

Courtney, T.K., Chang, W.R., Gr nqvist, R. and Redfern, M., Measurement of Slipperiness – An International Scientific Symposium, Ergonomics, 44:13, 1097-1101, 2001a.

Courtney, T.K., Sorock, G.S., Manning, D.P., Collins, J.W., and Holbein-Jenny, M.A., Occupational Slip, Trip, and Fall-Related Injuries – Can the Contribution of Slipperiness Be Isolated?, Ergonomics, 44:13, 1118-1137, 2001b.

Dempsey, P.G., McGorry, R.W., Cotnam, J.P., and Braun, T.W., Ergonomics Investigation of Retail Ice Cream Operations, Applied Ergonomics, 31:121-130, 2000.

Gr nqvist, R., Abeysekera, J., Gard, G., Hsiang, S.M., Leamon, T.B., Newman, D. J., GieloPerczak, K., Lockhart, T.E., and Pai, C.Y.C., Human-Centered Approaches in Slipperiness Measurement, Ergonomics, 44:13, 1167-1199, 2001a.

Gr nqvist, R., Chang, W.R., Courtney, T.K., Leamon, T.B., Redfern, M.S. and Strandberg, L., Measurement of Slipperiness:  Fundamental Concepts and Definitions, Ergonomics, 44:13, 11021117, 2001b.

Gr nqvist, R., Hirvonen, M., Rajamaki, E., Matz, S., A Prototype Test Instrument for

Determining Floor Slipperiness During Simulated Heel Strike: Validity and Reliability of Transitional Friction Measurements, accepted for publication in Accident Analysis & Prevention, 2001c.

Gr nqvist, R., Hivone, M., and Rajam ki E, Development of a Portable Test Device for Assessing On-Site Floor Slipperiness:  An Interim Report, Applied Ergonomics, 32:163-171, 2001d.

McGorry, R.W., A System for the Measurement of Grip Forces and Applied Moments During Hand Tool Use, Applied Ergonomics, 32:271-279, 2001.

McGorry, R.W., Chang, C.C., Teare, P.R. and Dempsey, P.G., A Hand-Held Computer Based Ergonomic Evaluation Tool, accepted for publication in Ergonomics in Design, 2001.

Redfern, M.S., Cham, R., Gielo-Perczak, K., Gr nqvist, R., Hirvonen, M., Lanshammar, H., Marpet, M., Pai, C.Y.C., and Powers, C., Biomechanics of Slips, Ergonomics, 44:13, 1138-1166, 2001.

Snook, S. H. and Ciriello, V. M.;  The design of manual handling tasks:  revised tables of maximum acceptable weights and forces. Ergonomics, 34:9 ll97-l2l3, l99l.

Snook, S. H., Vaillancourt, D. R., Ciriello, V. M., and Webster, B. S. ;  Psychophysical studies of repetitive wrist flexion and extension. Ergonomics, 38:7,1488-1507, l995.

Snook, S.H., Ciriello, V.M., and Webster, B.S. ; Maximum acceptable forces for repetitive wrist extension with a pinch grip.  International Journal of Industrial Ergonomics, 24:579-590,1999.

Snook, S.H., Vaillancourt, D.R., Ciriello, V.M., and Webster, B.W. ; Maximum acceptable forces for repetitive ulnar deviation of the wrist. American Industrial Hygiene Association Journal. 58:509-517, 1997.

Part III – Product Development and Applications of Research

 Wayne S. Maynard, CSP, CPE

A major responsibility of safety professionals is to recommend changes or interventions that will eliminate or reduce the major loss areas in the workplace. These responsibilities also include assisting with implementation of these interventions and to measure effectiveness over time. Since change means resistance, the safety professional needs to be equipped with knowledge, skills and tools to do their job effectively. Supporting these tangibles and intangibles are tools, references, and resources or service products . The role of the Product Director in Loss Prevention is to develop service products that will help the safety professional to be successful their jobs.

The synergy that exists between the research agenda at the Liberty Mutual Research Center for Safety & Health, the development of service products that strengthen a safety process and achieve results is the central theme behind From Research To Reality      .

Figure 1. illustrates the product development process at Liberty Mutual Loss Prevention. Major loss areas as identified in the Liberty Mutual Workplace Safety Index are on the left and the outcomes of research are illustrated on the right.

Product Development

The Product Development Model at Liberty Mutual

Outcomes of research are made available to the public through published peer-reviewed articles, conference proceedings articles, professional articles such as Professional Safety, niche journal articles, and Technical Memoranda. Technical Memoranda (TMs) are internal Liberty Mutual Loss Prevention references written by researchers that address epidemiology, ergonomic assessment, disability management, slips and falls, work system design and more. Service products reference Research Center Research which then moves research out of the Research Center to the field organization and in turn the customer.

Service Products

A change made in the job, task, workstation, tool, or organization as a direct result of guidance or assistance offered by the safety professional is called a Result. Figure 2. illustrates the relationship between Service Products and Results. Results almost always translate to financial savings for the business in terms of increased productivity and injury cost savings. Service Products include tools used to help with exposure assessment and support recommended action plans. Products such as References and Training are key to professional development in safety and health.


Figure 2.

Research Based Service Products and Results

The examples below illustrate how research based products assist with recognition evaluation and control of major loss areas identified in the Workplace Safety Index:

  1. Overexertion (excessive lifting, pushing, pulling, holding and carrying) and Bodily Reaction (bending, climbing and slipping without falling). Figure 3. illustrates tools, references and training that assists with manual materials handling injury and hazard surveillance, job analysis and design and training and education:
    • CompuTask2 – an ergonomic analysis software program that includes a manual materials handling module to assess lift, lower, push, pull and carrying tasks, an energy expenditure module, a repetitive wrist motion module and a NIOSH Lifting Equation module. CompuTask2 is used when a psychophysical and physiological approach is warranted. Outputs such as population percentages and kcal/min. are used to support task redesign recommendations and to perform what-if studies and before and after intervention studies2, 3.
    • VidLiTeC – an ergonomics analysis software tool based on a biomechanical model is used similar to CompuTask2    when a biomechanical model is appropriate1.
    • The TM Trends in Disability Duration and Cost of WC LBP Claims provides low back pain (LBP) claims cost statistics and is helpful for cost/benefit discussions of ergonomic interventions and importance of disability management programs16, 17, 19.
    • Vendors of back belts often promote their products as preventive of LBP however research has not shown this to be the case. Those against back belts state harmful effects from wearing them. Regardless, LP 5012 Back Belts offers a state of the art position on the pros and cons of wearing back belts and a summary of key research findings7.
    • Job and task redesign has been shown to be the most effective control method in preventing low back pain and disability. Task redesign principles are presented in LP

155 Principles of Task Redesign. Medical selection and training are also interventions in addition to but not in lieu of job design3, 4, 5, 6.

  • The public directly benefits from research in training session content offered by Liberty Mutual at the mixed customer Ergonomics Institute and dedicated ergonomics training sessions given on-site to managers, ergonomic task force members and supervisors.




LP 5012 Back Belts
Tech. Memorandum:

Trends in Disability

Duration and Cost of

WC LBP Claims

LP 155 Principles of Task Redesign
Training – Preventing Back Injuries

Ergonomics Institute

Figure 3.

Illustration of Manual Materials Handling Service Products

  1. Falls on same level and Falls to lower level. Figure 5. illustrates tools, references and training that assists with slips and falls analysis and evaluation, slip and fall prevention programs and training and education:
    • Safety Training Workshop (STW) Preventing Indoor Slips and Falls is a public training session that references slip and fall trends, floor slipperiness measurement and fall prevention programs. Cause and prevention of slips and falls is described using the science of tribology (friction, lubrication and wear). This STW supports the analysis and design element of the safety process by providing guidance on root cause analysis of slip and fall injuries and targeting interventions toward those root causes10, 11, 20, 21.
    • The TM Tribology; A Key Part of Slips and Falls Prevention is an internal training reference to help Consultants understand the science of tribology and relevance to slips and falls.
    • The Horizontal Pull Slipmeter (HPS) was developed by Liberty Mutual and supported by ASTM Test Method F609. Liberty Mutual also uses the Brungraber Mk II and English VIT slip meters for wet or contaminated floors.
    • Data Sheet 25 provides instructions in how to use these slip meters and interpret results.
STW Preventing Indoor Slips and Falls
Tech. Memorandum

Tribology; A Key Part of

Slips and Falls Prevention

Brungraber Mk II, HPS slipmeter, English XL
Tech. Memorandum:

Slip Resistance


Technical Bulletin 38 Slips and Falls
Data Sheet 25 Slips/Falls

Leading Loss Causes

Falls-Same Level

Falls-Lower Level


Figure 4.

Illustration of Slips/Trips and Falls Service Products

  1. Repetitive Motion. Figure 5. illustrates tools, references and training that assists with repetitive motion analysis and evaluation, prevention programs including contribution of exercise and stretch programs, hand tool design and training and education. Design of machine safeguarding systems is included for discussion here since it is upper extremity related.
    • Machine guard standard drawings are a series of references for in-running rolls and machine tool points of operation that provide guard safe opening distances depending on distance from the point of operation22.
    • The CompuTask2 repetitive wrist motion module provides female population percentages for repetitive wrist flexion, extension and ulnar deviation motion tasks with pinch and power grips. Type of motion and grip, repetition rate and force is selected and population percentage is computed12, 13, 14 . This module is used to support task redesign action plans for repetitive wrist motion jobs.
    • Exercise and stretch break programs are often cited as interventions to prevent repetitive motion disorders but do they work and what should a stretch break program look like?

LP 5067 provides answers and guidelines for customers who want to implement such programs9.

  • Understanding claims frequency and disability cost trends for repetitive motion disorders is important when determining cost/benefit of interventions. Safety Training Workshop (STW) Industrial Ergonomics and analysis, evaluation and control of upper extremity disorders in the Ergonomics Institute address this topic15, 18.
  • The Musculoskeletal Stress Measurement Kit (MSMK) is a series of tools used for collecting peak and average forces for pushing and pulling tasks, knife cutting tasks, screw driving tasks, and using pliers. The MSMK supports CompuTask2.
  • LP 190 Principles of Hand Tool Selection provides ergonomic design specifications for hand tools including when to use and not use bent angled tools or so called ergonomically designed hand tools8.
Machine guard safe opening distance standard drawings
LP 5067 Exercise/CTDs
STW – Industrial Ergonomics
Musculoskeletal Stress Measurement Kit
LP 190 Principles of Hand Tool Selection
Ergonomics Institute

Leading Loss Causes

Repetitive Motion



Figure 5.

Illustration of Repetitive Motion Service Products


 Research has provided a wealth of information to help safety and health practitioners and organizations manage their safety and health process, be successful and achieve results. The availability of research based Service Products to not only Liberty Mutual Loss Prevention Consultants but to any interested party worldwide helps achieve Liberty Mutual Group s vision of helping people live safer more secure lives and the Research Center for Safety & Health s vision of From Research To Reality         .


  1. Hsiang, S.M., Brogmus, G.E., Martin, S.E., and Berzverkhny, I.B. (1998), Video Based Lifting Technique Coding System, Ergonomics, 41:3, 239-256.
  2. Ciriello, V.M., Snook, S.H., and Hughes, J. (1993), Further studies of psychophysically determined maximum acceptable weights and forces, Human Factors, 35:175-186.
  3. Snook, S.H., and Ciriello, V.M. (1991), The design of manual handling tasks: revised tables of maximum acceptable weights and forces, Ergonomics, 34:1197-1213.
  4. Snook, S.H. (1987) Approaches to the control of back pain in industry: Job design, job placement and Education/training, SPINE: State of the Art Reviews, 2:1, 45-59.
  5. Snook, S.H., Campanelli, R.A., Hart, J.W. (1978), A study of three preventative approaches to low back injury, Journal of Occupational Medicine, 20:7, 478-481.
  6. Snook, S.H., (1988), Comparison of different approaches for the prevention of low back pain, Applied Industrial Hygiene, 3:3, 73-78.
  7. Ciriello, V.M., Snook, S.H. (1995), The effect of back belts on lumbar muscle fatigue, SPINE, 20:11, 1271-1278.
  8. Dempsey, P.G., Leamon, T.B., (1995), Bending the tool and the effect on productivity: an investigation of a simulated wire-twisting task, AIHA Journal, 56:686-692.
  9. McGorry, R.W., Courtney, T.K., (1995), Exercise and Cumulative Trauma Disorders; The Jury Is Still Out, Professional Safety, June, 22-25.
  10. Leamon, T.B., Murphy, P.M. (1995), Occupational slips and falls: more than a trivial problem, Ergonomics, 38:3, 487-498.
  11. Murphy, P.L. and Leamon, T.B. (1997), Events and Exposures Related to Slips, Trips and Falls in Industry, Proceedings of the 13th Triennial Congress of the International Ergonomics Association, Tampere, Finland, 3:393-395.
  12. Snook, S.H., Vaillancourt, D.R., Ciriello, V.M., and Webster, B.S. (l995), Psychophysical studies of repetitive wrist flexion and extension. Ergonomics, 38:7, 1488-1507.
  13. Snook, S.H., Vaillancourt, D.R., Ciriello, V.M., and Webster, B.S., (1997), Maximum acceptable forces for repetitive ulnar deviation of the wrist, American Industrial Hygiene Association Journal, 58:509-517.
  14. Snook, S.H., Ciriello, V.M., and Webster, B.S., (1999) Maximum acceptable forces for repetitive wrist extension with a pinch grip, International Journal of Industrial Ergonomic, 24:579-590.
  15. Webster, B.S., Clancy, E.A. and Courtney, T.K, (1997), Length of disability and cost of work-related musculoskeletal disorders of the upper extremity, Hashemi, L., et al., Journal of Environmental Medicine, 39:10, 937-945.
  16. Webster, B.S., Snook, S.H., (1990), The cost of compensable low back pain, Journal of Occupational Medicine, 32:1, 13-15.
  17. Webster, B.S., Snook, S.H., (1993) The cost of 1989 workers compensation low back claims, SPINE, 19:10, 1111-1116.
  18. Webster, B.S., Snook, S.H., (1994), The cost of compensable upper extremity cumulative trauma disorders, Journal of Occupational Medicine, 713-717.
  19. Dempsey, P.G., Hashemi, L., (1999), Analysis of workers compensation claims associated with manual materials handling, Ergonomics, 42:1, 183-195.
  20. Gr nqvist, R. (1995), Mechanisms of friction and assessment of slip resistance of new and used footwear soles on contaminated floors, Ergonomics, 38:2, 224-241.
  21. Chang, W. (1999), The effect of surface roughness on the measurement of slip resistance, International Journal of Industrial Ergonomics, 24:299-313.
  22. Vaillancourt, D.R., Snook, S.H. (1995), Review Of Machine Guarding Recommendations, Applied Ergonomics, 26:2, 141-145.