Dear Mr. Stefan Kratzenstein,

I would propose : 1 st:  ear protection against hearing damage

                                  2nd: protection against biologic agents: be sure about protection by hepatitis A and B vaccination, tetanus and rabies vaccination. Persons with important health problems should be aware of the risks of contamination with some harmful insects or other biological agents. For example pregant women should be warned for it.

Best wishes,

Elisabeth van der Gulik, MD

I recommend these articles of Prof. J. Malchaire (he is on the site of RG):

- J. Malchaire, A. Piette, T. Belem, Lundstrom R. (2001), Neurological and Functional Effects of Short Term Exposure to Hand-Arm Vibration, Appendix H3E to Final Report EC Biomed II concerted action BMH4-CT98-3291

- Malchaire J., Piette A., Cock N. (2001) Associations Between Hand-Arm Musculoskeletal And Sensorineural Complaints And Biomechanical And Vibration Work Constraints. The Annals Of Occupational Hygiene. 45, 6, 479-491.

- Cock N., Piette A., Malchaire J. (2000) Can A Battery Of Functional And Sensory Tests Corroborate The Sensorineural Complaints Of Subjects Working With Vibrating Tools? International Archives Of Occupational And Environmental Health 73, 5, 316-323.

- J. Malchaire, A. Piette and I. MullierI, VIBRATION EXPOSURE ON FORK-LIFT TRUCKS; Ann. occup. Hyf., Vol. 40. No. 1, pp. 79-91, 1996

 hope this papers will help you.

Good reading

Dear Kratzenstein:

Your question is very interesting, and it is within my scientific interests (occupational safety and health). From this point of view, I would like to comment the following:

1. The standards EN ISO 5349 and CEN / TR 15350 indicate among other things, that lel HAV value depends (among others) of the gripping force of the worker;

2. Fatigue, from an ergonomic point of view, can be evaluated with methodologies related to awkward postures, such as REBA, OWAS, RULA, etc.

3. The combination of vibration and awkward postures may be considered a synergistic risk factor. At the same time, this combination can be considered an emerging risk.

That said, in relation to grass trimmers, I know studies have assessed the risk factor by HAV and awkward postures, but considering these factors independently.

In any case, in summary, I recommend you focus your study as a combination of methodologies HAV and awkward postures.

I hope I have helped.