Anti-vibration Gloves - in Theory and Practice

Abstract

Vibrations from hand-held machinery are a major problem in the Swedish labour force. In 2009, 14% of men and 3% of women of employed in Sweden reported exposure to hand-arm vibration at least a quarter of their working time according to the Swedish Work Environment Authority (Arbetsmiljöverket 2010). It is tempting to imagine a protective glove that could reduce or even eliminate this problem. This report from the Department of Occupational and Environmental Medicine in Lund and Gothenburg describes how anti-vibration gloves (AVGs) are experienced, and how they work and affect the exposure from hand-held machines. Generally, all protective equipment disrupts work to a greater or lesser degree. Working without a helmet, protective mask, hearing protection, and protective clothing is preferred in most situations. Furthermore, the availability of gloves which are supposedly AV may give rise to an ethical dilemma: the user may handle the machines more intensely and for a longer time in the belief that the hand is protected from vibration damage. But are those AV claims true and how do these gloves perform in practice? Is the experience regarding the gloves that they dampen the vibrations? To what extent do the gloves disturb the worker and interfere with the work? How much damping can be expected when using low-speed and high-speed grinders, respectively? These issues will be discussed in the following report. Nine subjects, whose work task was to deburr and grind aircraft engine components, were given the opportunity to test a specific AVG for 3 months. They all worked with a variety of rotating air-powered and vibrating machines. Only one model of AVG was tested. The glove was CE-marked and was claimed to comply with standard ISO 10819:1996. The test subjects tried the glove for 3 months. After this period, they answered a questionnaire containing 14 questions including questions on hand temperature, grip, dexterity and self-reported vibration damping. To assess the usefulness of the AVG, the vibration level and vibration frequency spectrum were measured on the machines used by the subjects. During the measurements, a skilled operator performed a typical deburring task. The vibrations from many of the machines in this study, which are used over long periods for deburring, will be damped to some extent. But it is not obvious that this damping neither can be experienced, nor give reduced daily vibration exposure in accordance with the regulations, or reduce the risk of vibration injury in the hands. So-called “AVGs” generally give insufficient reduction in vibration exposure. This is demonstrated already by the standard for CE certification of AVGs. For a glove to protect against normal, low-frequency vibrations, it would have to be too heavy and thick to be practical. Despite the limitations of the protection that the CE-marked protective gloves offer against vibrations, we still recommend the use of gloves because: 1. High-frequency vibrations, which are presumed to be harmful, will be damped. 2. The gloves will ensure that vibrations will not be amplified. 3. Gloves keep the hands warm, which is believed to reduce vibration-related disorders.