Effect of whole-body vibration on the low back - A study of tractor-driving farmers in north India

Study Design. A retrospective cohort study of tractor-driving farmers (stud y group) and non-tractor-driving farmers (control group) matched for age, g ender, generic/ethnic group, land-holding, and work routines. Objectives. To determine, using magnetic resonance imaging and clinical inv estigations, the effect of whole-body vibrations on the back in tractor-dri ving farmers. Summary of Background Data. Low back pain and pathologic changes in the low er backs of tractor drivers have been reported. However, no study with a co ntrol group matched for work-related risk factors has been reported. Methods. Fifty tractor-driving farmers were compared with 50 non-tractor-dr iving farmers matched for age, gender, ethnic group, land-holding, and work routine. Both groups were interviewed for details of work routine, assests held, family profile, and vibration exposure to assess the influence of th ese parameters on signs and symptoms of backache. Magnetic resonance imagin g was done to assess the effect of exposure on whole-body vibration and deg enerative changes in the back. Vibration measurements also were done on tra ctors to observe the actual severity of the vibrations. Results. Regular work-related backache was more common among tractor-drivin g farmers (40%) than among non-tractor-driving farmers (18%, P = 0.015). An thropometric evaluation showed abdominal girth and weight to be significant ly higher in tractor-driving farmers (P = 0.006 and 0.046, respectively), w hereas while height and arm span were similar between the two groups. Clini cal examination for evidence of disc or facet degeneration showed no differ ence between the two groups. Evaluation of magnetic resonance images of tra ctor-driving farmers and non-tractor-driving farmers by an orthopedic surge on, radiologist, and neurosurgeon showed degenerative changes to be similar between the two groups (P > 0.050). Conclusions. Tractor-driving farmers report backache more often than non-tr actor-driving farmers, but no significant objective differences on clinical or magnetic resonance imaging evaluation were found between the two groups .