Comparison of lumbar curves when sitting on the Westnofa Balans Multi-Chair, sitting on a conventional chair, and standing.

The purpose of this study was to determine whether the Balans Multi-Chair (BMC) approximates the amount of standing lumbar curve better than a standard conventional chair (SCC) in seated subjects writing at a desk. The length of the curve from L1 to S2 was measured with a flexible ruler in 44 healthy subjects who were standing and sitting on both an SCC and a BMC. A one-way analysis of variance for repeated measures and the Student-Newman-Keuls test were used to examine the differences in the curves created in the three positions. The frequency of subjects sitting in lumbar flexion was compared using a chi-square test with those not in flexion. Lumbar curves measured in the three positions were significantly different (p less than .01). The BMC approximated the standing lumbar curve in seated subjects writing at a desk to a greater degree than the SCC. In addition, the BMC produced lumbar flexion less frequently (chi 2 = 4.33, p less than .05) than did the SCC. These data suggest that the BMC may be an appropriate adjunct in client care when minimal lumbar flexion or lumbar extension is indicated.