Vibration analysis of the sulky accessory for a commercial walk-behind lawn mower to determine operator comfort and health

A sulky is a single-wheeled platform attachment on which the operator of a commercial walk-behind lawn mower rides while standing. The effects of sulky vibration on operator comfort and health have not been investigated. In this study, tri-axial accelerometers measured sulky vibration during mower use by two commercial mowers on varied terrain and 12 volunteer mowers over a controlled course. The accelerometer data were processed according to methods established in ISO 2631. Results indicate the mean frequency-weighted root mean square (RMS) acceleration sums fall into the 'very uncomfortable' range for vibration of standing persons (1.9 ± 0.48 m s^-2). Additionally, vibration dose values indicated that the mean vibration dosages exceeded the daily exposure limit values established in Directive 2002/44/EC (z-axis A(8) value of 1.30 ± 34 m s^-2; VDV_exp value of 28.1 ± 6.25 m s^-1.75). This information suggests that modifications including vibration damping should be added to the sulky to reduce rider discomfort and health risks. Practitioner Summary: This study investigated the effects of vibration during use of a commercial lawn mowing sulky. Findings from accelerometer data suggest that the vibration experienced by sulky operators is significant enough to cause discomfort and health risks which may lead to personnel turnover or long-term effects for the operator.