North Texas Safety Consulting Services
Rate a task’s effort, duration, and frequency for each body region and get a Priority for Change — the published screening method ergonomists use to find the jobs where muscle fatigue builds up fastest.
Break the job into its tasks first. Analyze the tasks that take more than 10% of the shift, plus any task workers consider difficult — no matter how small a share of the shift it is. Use one analysis per task.
For every region the task loads, pick the effort level that best matches the work, then the continuous effort duration (how long one effort is held before a brief rest) and the effort frequency (how often that effort repeats). Duration and frequency describe the effort level you just chose.
Three ratings trigger an automatic Very High priority on their own: a Very Heavy effort (most people could not perform it), a continuous effort lasting more than 30 seconds, or efforts repeating more than 15 times per minute. Every other combination is scored from Rodgers’ published priority table.
Task: not named yet
Rate all three factors for at least one body region and the overall priority will appear here. The overall priority is the highest priority among the regions rated.
| Body region | Effort level | Duration | Frequency | Priority for Change |
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Email this analysis to Scott Weede, CIE, at North Texas Safety Consulting Services for a professional review — what to change first, and how. Your name and company are optional; the task ratings ride along either way.
The button opens your own email program with the results filled in, addressed to scott@ntscs.com. Nothing is sent until you press send there.
The Muscle Fatigue Analysis was proposed by Suzanne H. Rodgers as a means to assess the amount of fatigue that accumulates in muscles during various work patterns. The underlying idea: a rapidly fatiguing muscle is more susceptible to injury and inflammation — so if fatigue can be minimized, injuries of the active muscles should be minimized too.
The method is best suited to tasks performed for an hour or more where awkward postures or frequent exertions are present. Rate the task as it is performed today; after a change is made, rate it again with the same tool to confirm the fatigue — and the Priority for Change — actually dropped.
References: Rodgers, S.H., “A functional job evaluation technique,” in Ergonomics, Occupational Medicine: State of the Art Reviews 7(4):679–711, 1992; Rodgers, S.H., “Job evaluation in worker fitness determination,” Occupational Medicine: State of the Art Reviews 3(2):219–239, 1988. Ratings, descriptors, and the Priority for Change table follow Rodgers’ published analysis worksheet.