An Exploratory Study Comparing the Hand Arm Vibration Exposures Measured from Bucking Bars using Traditional Tool-mounted Accelerometers and Wrist Worn IMUs

Abstract

This controlled, exploratory laboratory study was conducted to measure hand-arm vibration (HAV) exposures when using a bucking bar fitted with three different handles: 1) a typical plastic handle, 2) a similarly designed handle with an aluminum core and a built-in dampening spring, and 3) a steel core handle with the same built-in spring. Using two experienced machinists, tri-axial HAV exposures were measured at the bucking bar handles; small, battery-powered, self-contained Inertial Measurement Units (IMUs) were used to measure the vibration transmitted through the tool operator’s left and right arms; and a wearable device worn on the operator’s right wrist estimated the HAV exposures occurring at the tool handle. The plastic handle produced the highest HAV exposures while the aluminum-spring and steel spring handles reduced exposures by 19% and 39%, respectively. On average, 74%, 65% and 40% of the tool-measured vibration was transmitted to the right hand, forearm and upper arm, respectively. The wrist mounted sensor appeared to accurately estimate HAV exposures measured at the hand-tool interface.