Seat suspension design for reduction of whole-body vibration of forklift drivers in warehouse

Background: Whole-body vibration transmitted through the seat during forklift operation significantly contributes to musculoskeletal disorders among forklift operators. Objectives: The study aims to design vibration absorbing materials for forklift driver seats and to compare whole-body vibration levels before and after implementing the new design Methods: This study employed a quasi-experimental research design to compare whole-body vibration levels before and after the implementation of an absorption material in forklift seat design. The study population consisted 34 forklift drivers working in the warehouse department of an electronics manufacturing and assembly plant in Chachoengsao province. This experimental study was conducted over a seven-month period. Results: The result of combination of butyl rubber sheets that were 25 x 25 x 1.5 cm in width, length and thickness, as well as layer 1 and layer 2 foam sponges that were 53 x 42 x 5 cm in size, improved the materials inside the seat. The measurement of the whole-body vibration exposure compared to the average period of 8 hours A (8) before and after the design of the vibration absorbing material inside the forklift seat showed significant differences in all three cases. While comparing the measurement group's vibration values to the ISO 2631-1, 1997 standard over an 8-hour period [A (8)], it was discovered that the vibration value exceeded the standard by 97.06% of 100% prior to design, and that the vibration exceeding the standard decreased to 50.00 percent of all measurements following design. Conclusion: This study concludes that incorporating butyl rubber and foam sponge into forklift driver seats effectively reduces whole-body vibration transmitted through the seat during forklift operation.