Electromyographic comparison of two lumbar support mechanisms intended for automotive seating applications

Abstract

The purpose of this study was to compare and contrast the effect of two lumbar support mechanisms on low back muscle activity. These mechanisms were designed to provide either microadjustment or massage. In the control condition, 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 traditional lumbar support design, was used to obtain an indication of the typical amount of low back muscle activity expected from automotive sitting. The data were collected using surface electrodes located at the L3 and L5 levels. Both lumbar support mechanisms provided a small reduction in low back muscle activity during a 1 h session. This can be contrasted with the control condition, which resulted in a small increase. In this respect, the mechanisms were considered an improvement on traditional lumbar support designs.