An observational method for classifying exposure to repetitive movements of the upper limbs

This article presents and discusses a model for describing and evaluating the principal risk factors characterizing occupational exposure: frequency and repetitiveness of movements; use of force; type of posture and movements; distribution of recovery periods; and presence of other influential (additional) factors. For each risk factor, the author proposes a method of practical detection in the field, as well as criteria for classifying and interpreting the results based on a critical review of the available literature on the subject. Numerous examples are supplied to better illustrate the concepts presented. The various factors considered are classified using numbers or indexes, so that they can be integrated into a concise exposure index.