Electromyographic comparison of two lumbar support mechanisms intended forautomotive seating applications

The purpose of this study was to compare and contrast the effect of two lum bar support mechanisms on low back muscle activity. These mechanisms were d esigned to provide either microadjustment or massage. In the control condit ion, the lumbar support mechanism was set to the full-off position (0 mm of mechanism prominence). In this position, the foam contour supplied only a minimal amount of support. This condition, which is representative of tradi tional lumbar support design, was used to obtain an indication of the typic al amount of low back muscle activity expected from automotive sitting. The data were collected using surface electrodes located at the L3 and L5 leve ls. Both lumbar support mechanisms provided a small reduction in low back m uscle activity during a I It session. This can be contrasted with the contr ol condition, which resulted in a small increase. In this respect., the mec hanisms were considered an improvement on traditional lumbar support design s.