The objectives of this study were to carry out a literature review of issues related to load and frequency
in manual handling, and in the light of the findings to develop a method of risk assessment that could be
applied to jobs, such as order picking, where either the load or frequency of handling are very variable.
It is widely assumed that variation in manual work is beneficial for workers, but little evidence was found
to support or refute this. Assessing variable manual handling is inherently difficult and existing methods concentrate on single constant tasks. Cumulative mass limits exist in various national guidelines and an international standard but are inconsistent. Use of such a mass limit independent of frequency of handling
is contrary to evidence that the amount that can be handled increases with the frequency of handling.
proposed V-MAC (variable MAC) uses the traffic-light approach of the MAC to consider the load-frequency
distribution of the objects that an individual handles during a shift. A draft MS Excel workbook has been
developed to implement it. It should be tested for usability by inspectors of health and safety and dutyholders
familiar with carrying out risk assessments of manual handling.
This report and the work it describes were funded by the Health and Safety Executive (HSE). Its contents, including any opinions and/or conclusions expressed, are those of the author alone and do not necessarily reflect HSE policy.
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