Assessment of whole body vibration among forklift drivers using ISO 2631-1 and 2631-5
The use of forklifts to move material is very common in large manufacturing companies. Exposure to whole body vibration from industrial vehicles such as forklifts has been associated with low back pain and also with the degeneration of intervertebral disc. Predicted health risks, associated with the operation of forklifts, based on ISO 2631-1 criteria are limited and have not yet been determined according to ISO 2631-5 criteria. Therefore, the objective of this study was to quantify the whole body vibration exposure levels during the operation of different types of forklifts and to quantify WBV exposure levels using ISO 2631-1 and ISO 2631-5 standards. Hence, health risks predicted by ISO 2631-1 and 2631-5 criteria are reported and compared in this study. This research was conducted at a local aircraft manufacturing company in Wichita, KS. Vibration exposure was measured according to procedures established in ISO 2631-1. A triaxial seat pad accelerometer was used to measure vibration exposure at the operator/seat interface. Vibrations were measured passively with the use of a battery-operated datalogger while employees drove their forklifts during a normal work day. The results were compared in accordance to frequency-weighted r.m.s values, vibration dose values, equivalent compressive stress Sed and the R factor. According to ISO 2631-1 criteria, two forklift operators were identified to have a high risk of exposure and three forklift operators were identified to have a moderate risk of exposure in accordance with health guidance caution zone (HGCZ) boundaries with A (8) as a measure. Similar results were achieved from the Sed and R factor values which were the measure of ISO 2631-5. Adverse health effects on the lumbar spine according to ISO 2631-5 were always lower than the risks predicted by ISO 2631-1 criteria. But, VDV (a measure of ISO 2631-1) showed similar results with ISO 2631-5 measures.
Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Industrial & Manufacturing Engineering