ABSTRACT:
Introduction:Tillers or hand tractors are widely used in small or medium-sized farms where it is difficult to operate big four-wheel tractors. The tiller operators are exposed to excessive vibration while working with this machine. Materials and Methods:The aim of this study was to measure the whole body vibration exposure in tiller users. In this study, 40 tiller users were investigated. The vibration measurements were carried on using two different methods. The first method was based on ISO 2631 Standard guidelines and the second method utilized body vibration measurement sensors installed on the user's back. Finally, the results of two methods were compared. Results:The whole body vibration parameters such as root mean square acceleration (RMS), total equivalent acceleration vibration dose value (VDV) and crest factor were separately calculated in three directions (x,y, and z) in three different operating modes. To measure the level of vibration, Human Response Vibration Meter Type 2512 was used. The results of the study indicated that the greatest vibration exposure was in rota-tilling mode when the tiller was in the 2nd gear (532 m/s2) and the 1st gear 1(5.09 m/s2). Under these conditions, the exposure to whole body vibration exceeded the permitted value and there was a risk of health disorders. The highest value of crest factor was in idling mode (4.14) and the maximum vibration dose was in rota-tilling mode in 2nd gear (20.65 m/s1.75). In all measurement modes, the exposure to vibration in the direction of x was greater than y and z directions. Conclusion:The results of this study showed that tiller operators were exposed to whole body vibration higher than the permitted level. As such, standard methods are required to measure whole body vibration in tiller operators in both walking and riding modes.