Tying indications of musculoskeletal disorders to identifiable job risk factors is important to establish work relatedness and to define the basis for a control plan. As described in Step 4, walk-through observational surveys of the work facilities, interviews with workers and supervisors, and checklists can all be useful for identifying risk factors. Checklists can offer an orderly procedure for screening jobs for risk factors of consequence to musculoskeletal disorders, although there is scientific debate over the ability of checklists to differentiate hazardous from non-hazardous tasks or conditions. Indeed, some checklist items, as written, are vague or call for judgments that defy simple observations for a lack of concrete references (e.g., Are materials moved over minimum distances? "What are minimum distances?"). Common practice is to follow up checklist observations with more precise techniques to confirm problem risk factors.

When using checklists or other more in-depth job analysis techniques, it is important to observe several workers doing a particular job to see if workers of different body sizes use different postures or practices to accomplish the task. One worker will not provide a representation of the way all workers perform the task or of the potential risk factors present.

Various forms and types of checklists exist. The University of Utah Research Foundation has published several on their ERGOWEB Internet site (http://ergoweb.mech.utah.edu/). One of these checklists is for undertaking a general ergonomic risk analysis to identify basic categories of job demands and workplace conditions that may pose a problem. An adaptation of this general checklist form is included in Tray 5–A. "Yes" answers given to questions within each category determine which areas may require follow-up, using more detailed types of analyses. NIOSH staff has also used a general checklist as a first means for localizing potential problems. It is described in Tray 5–B and focuses on primary job activities.

No one checklist can fit all situations, and it is suggested that checklists be customized for use with different job tasks or types of work so that problems will not be overlooked. Five additional checklists are included, each focusing on different workplace conditions and job task factors. The checklists cover:

Workstation Layout (Tray 5–C)
Task Analysis (Tray 5–D)
Handtool Analysis (Tray 5–E)
Materials Handling (Tray 5–F)
Computer Workstation (Tray 5–G)

One or more of the checklists or items within several checklists can be used or combined to compose a form that is most appropriate for the particular work situation. These five checklists are written so that a "No" response indicates potential problem areas deserving more investigation.

Other versions of checklists are located in the following references:

Lifshitz Y, Armstrong T [1986]. A design checklist for control and prediction of cumulative trauma disorders in hand intensive manual jobs. Vol. 2. Proceedings of the 30th Meeting of the Human Factors Society, Daytona, Florida, pp. 837–841.

Bhattacharya A, McGlothlin JD, eds. [1996]. Occupational ergonomics. Appendix B. New, York, NY: Marcel Dekker, Inc., pp. 783–802.

Keyserling WM, Brouwer M, Silverstein BA [1992]. A checklist for evaluating ergonomic risk factors resulting from awkward postures of the legs, trunk and neck. Int J Ind Ergonomics 9:283–301.

Keyserling WM, Stetson BA, Silverstein BA, Brouwer ML [1993]. A checklist for evaluating ergonomic risk factors assocated with upper extremity disorders. Ergonomics 36(7):807–831.

Checklists can help provide an initial identification of problem jobs or tasks which in some cases may be solved with quick fixes by easy-to-make workstation changes (e.g., the removal of a barrier that may be causing awkward twisting and lifting postures in handling materials). However, the checklist findings must be viewed as a whole to see if individual problem signs do not suggest the same underlying root cause. Targeting interventions to the basic cause in this situation, as opposed to addressing each problem sign, offers a much more effective solution.

Most frequently, followup activities obtain more definitive information on the suspect problems first identified through use of a checklist. As explained in the main text (see Step 4, Identifying Risk Factors in Jobs), added data collection can include (1) time-motion studies to furnish job task and cycle data, (2) measures of workstation layouts, (3) measures of tool handle sizes, weights, and vibration levels, (4) measures of exposures to whole-body vibration and thermal conditions, and (5) biomechanical and physiological determinations. Time-motion study and analyses remain a fundamental procedure in assessing potential problem jobs, and videotaping is typically used for this purpose. Tray 5–H describes a protocol used by NIOSH in videotaping jobs. Its aim is to assure sufficient job cycles, adequate angles of viewing, and variations in worker characteristics so as to offer a representative picture of the work situation for analyses. The analyses of the videotape itself requires special techniques, and much judgment can be needed in determining whether the job conditions present an increased risk of WMSDs. Analytical procedures can be prescribed for rating repetitiveness, force, and postural factors, but it is advisable that persons knowledgeable and experienced be consulted about doing this work.

THIS PAGE WAS LAST UPDATED ON SEPTEMBER 11, 1997