Simultaneous measurement of acceleration, grip and push force on chain saw for forestry: correlation with hemodynamic parameters.

Grip and push force in hand-arm vibration measurement procedures are well known influencing inputs. Many authors and some international standards highlighted the importance to take such inputs under control during tests and, if possible, to measure them. But still an easy and unique measurement method for coupling forces is not available. In this paper authors make use of a procedure for indirect measurement of coupling forces at hand-handle interface - based on the measurement of pressure distributions – and demonstrate its applicability in standard vibration tests on a chain saw. Results reported in this paper show correlations among forces and accelerations in different working conditions and changes of hemodynamic parameters of the operators before and after the test.