Abstract:
While anti-vibration gloves are widespread as a form of reducing employee exposure to hand-arm vibration (HAV) there is concern about how effective they actually are in a real manufacturing environment with specific tools. Currently ISO 10819 is used to certify gloves as “anti-vibration”; however, the standard only tests a static position and force which may not accurately represent a gloves ability to reduce vibration exposure during specific tasks.
The aims of this study are to examine 4 different types of gloves and see how effective they are at reducing vibration exposure in employees performing a specific workplace task. The first hypothesis tested is whether or not the gloves are different from the bare hand measurements. The null hypothesis is that there is no difference in vibration exposure when a glove is used. The second hypothesis evaluated is whether a difference can be observed between the gloves themselves. The null hypothesis is that there is no difference between the gloves. To determine the validity these two hypotheses, vibration exposure during a sanding task will be examined. The third hypothesis tested is whether the subjects’ perception of vibration reduction with the gloves matches the actual measured results. The null hypothesis is that there is no difference between subject perception and the measured results. This was done with a questionnaire given to the subjects asking them to rate the perceived vibration and rank the gloves in order of most effective to least.
A jitterbug-style orbital sander was mounted with a tri-axial accelerometer while the subject had another tri-axial accelerometer attached to the back of their hand and both were connected to the same data logger so that simultaneous measurements of both accelerometers could be taken. In a randomly assigned order the subject used each of the four gloves to take one minute samples from sanding both a vertical and a horizontal surface. The same was done for a barehanded measurement where the subject used no glove, also randomly assigned in the order. A ratio from the tool and hand samples was found for each glove to find the transmissibility factor. The gloved transmissibility factors were then compared to that subject’s bare hand sample to find the corrected transmissibility of the glove.
The results differed depending on which surface was used. On the horizontal surface there was not a significant difference between the gloves and the bare hand, but if the sample size would have been larger then there likely would have been. There was a significant difference between gloves; one of the gloves was found to amplify vibration exposure. On the vertical surface there was no difference between the gloves and the bare hand or between the gloves themselves. The subject rankings of the gloves did not closely resemble the actual results.
According to this study, ISO 10819 may not accurately depict a glove’s ability to mitigate vibration for specific tasks. The use of anti-vibration gloves may also be an ineffective way to try to reduce employee exposure to high levels of vibration.