The postural support of seats: a study of driver preferences during simulated tractor operation

The overall comfort of four current production tractor seats and some individual features of seat design have been assessed by a method of paired comparisons. The experiment was carried out under both static and dynamic conditions and subjects had to adopt natural postures similar to those adopted when ploughing. The results suggest that operators can differentiate seat comfort differences reliably. Subjects' posture has proved important particularly when assessing the height of the back rest. On the other hand most appraisals were not significantly affected by the conditions (dynamic or static) of the simulation. An exception to this was the cushion length. This experiment has finally produced enough information on the relative importance of various aspects to enable us to design an experimental seat to be used in a series of experiments to assess specific features of seat aspects. The ultimate objectives of this investigation are to determine what aspects of seat and workplace design affect the comfort of the operator and how these can be altered to improve the tractor driver's posture.