Design of seat support height based on the analysis of biomechanical characteristics of lumbar and abdomen muscles

Abstract:
To improve drivers' comfort, this work calculated the force between L1 to the sacral vertebrae and the activation of the lower back muscles of drivers with lumbar support. The lumbar support was placed at the height of the projection from the human sacrum to the L3 vertebral segment to the chair surface, and the calculation was carried out using the AnyBody Modeling System. The results show that under lumbar support with a backrest angle of 15deg and support protrusion of 4 cm, the intervertebral force and back activation of the driver show a negative correlation as the lumbar support position increases. The ideal lumbar height is the height projected to the chair surface from the L4 vertebral segment. At this height, the force of each vertebral segment increases by 2.71% on average. Except for the erector spine muscle, the activation of other main force-producing muscles in the lumbar and back decreases averagely by 39.8%. In the end, the verification test proved the rationality of the modeling and the reliability of the simulation experiment results. The method adopted lays a foundation of lumbar support design oriented towards the ideal driver’s intervertebral force and back activation and provides references for sat comfort design.