ABSTRACT

As has been documented by Bernard (1997), there is strong evidence that repetitive and forceful manual work can lead to musculoskeletal disorders of the hand/wrist (H/W-MSD) such as tendinitis and carpal tunnel syndrome (CTS). However, a “safe” level of daily repetitive manual workload has not been established. Quantitative determination of such a level among worker population is a difficult task, since many factors are known to be involved in the causation of H/W-MSD. Further, methodologies for objective and quantitative measurement of many of the exposure factors are not well developed. Therefore, establishment of dose-response relationship between the exposure and H/WMSD is much more complicated than that for chemical exposures (e.g. lead or toluene), where both the dose and resultant biochemical responses can be defined and measured. Despite these difficulties, there is a need for establishment of quantitative dose-response relationship for manual work. Without such quantitative guidelines, we do not know “How much is too much?” and preventive effort against H/W-MSD must remain in the realm of “trial and error” or “faith.” Regardless of whether an intervention effort resulted in a success or a failure, there ought to be a mechanism to determine why and how it was successful or unsuccessful, so that one may learn from the previous experience.