In this Indian study, 50 tractor drivers (TD) and a control group of 50 non-tractor drivers (NTD) were selected from the same ethnic group, economic status and location. All drivers were examined clinically, and health and socioeconomic background data and magnetic resonance imaging (MRI) scans of the spine were obtained for all subjects. The level of vibration inputs among the tractor drivers was obtained by measuring the vibrations experienced at the driver seat for 3 tractor models on village roads and farms. It was observed that the tractor driving farmers were subjected to whole body vibrations exceeding International Standards Organization (ISO) 2631-1 (1985, 1997) health limits. Tractor driving farmers reported regular back pain more often (56%) than non-tractor driving farmers (32%). However, MRI examination of the study group and control group did not reveal any significant difference in degenerative changes between the two groups, and disc degeneration levels were high in both groups. Disc degeneration as revealed by MRI investigation is not adequate to predict prevalence of back pain. It is possible that the cause of backache could lie in mechanisms and tissues that undergo changes not demonstrable by MRI and clinical evaluation.
Abstract