Overview of Ergonomic Assessment - Fundamentals and Assessment Tools for Occupational Ergonomics - page 668

. Robust — can be used in any work situation
. Inexpensive — the tool would be available at minimal monetary cost
. Noninvasive — the assessment would neither affect the way the worker performs his or her job, nor
would it affect the process workflow or quality of work
. Quick — the assessment and analysis could be performed quickly
. Easy to use — the tool could be used with minimal training

Of course, given technological limitations, no current assessment tool is perfect in all of those
attributes. Consequently, assessment tool developers must often make compromises. For example, com-
promises are often made between robustness and ease of use. Generally speaking, the more robust a
model, the more complex it becomes and, hence, the more difficult the model is to use. Conversely,
the easier the model is to use, the more limitations that are placed on how the practitioner can use
and interpret the results.

34.2 Use of Assessment Tools by Practitioners

Practitioners generally use assessment tools for any of four main purposes. Probably the most valuable
information that can be gained from an assessment is a measure of risk of injury. However, given the
complexity of determining the exact likelihood that an MSD that could result from a task, very few
assessment tools can provide an assessment of absolute risk. The tool that perhaps comes closest to
provide an assessment of risk is the lumbar motion monitor (LMM) system, as described by Marras
et al. (1993) and later validated in the field by Marras et al. (2000). The device and the accompanying
software output a probability that the task being analyzed is in a high-risk group (low back pain
incidence rate 12) given trunk kinematic data and physical workplace measures.

Another way that assessment tools can be incorporated into an ergonomics process is by using them to
prioritize job redesign efforts. The reality of business is that we live in a world with finite resources, and
the two most valuable resources are time and money. So, ergonomists and those involved in making
workplace changes must direct resources to where they can have the biggest impact. Results from analysis
tools can then be used to determine where intervention efforts, which involve both time and money,
can be focused. Comparisons of results from different redesign candidates can be coupled with other
information, such as cost and potential impact of interventions, to allocate resources.
Assessment tools can also help when developing the appropriate intervention strategy for a task. If a
tool has sufficient resolution, then the most hazardous components of a task can be determined and job
redesign can be used to lessen worker exposure to that particular component. For example, an assessment
tool may identify trunk flexion as a component that can lead to low back pain. An appropriate interven-
tion strategy could then focus on eliminating the need for the worker to bend the trunk, thus reducing
the risk of injury.
Finally, assessment tools can be used to evaluate the effectiveness of intervention measures.
Quantitative measures can be taken before an ergonomic intervention is implemented, and then the
same quantitative measure can be taken after the intervention is put into place. The results of the two
assessments can then be compared to ensure that the intervention had the desired effect of reducing
worker exposure to problem risk factors, and to also ensure that no additional risk factors have been
introduced. Additionally, the new results can be used as part of a continuous improvement process so
that future modifications can be made, if appropriate.

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34.3 Health and Medical Indicators

An initial step that can be taken to determine where MSDS problems are occurring in a facility is to
review existing records. Monitoring existing records is referred to as “passive surveillance” (Tanaka,
1996). One set of records that is commonly used in the United States is the OSHA 300 log, which the
Occupational Safety and Health Administration (OSHA) requires most employers to keep. Information