13. Lumbar support
- Many chair backrests do not have lumbar support. Lumbar support is found in the lower part of the backrest and is usually a small rounded-out area in the padding.
- When there is no lumbar support, the natural curve of the spine straightens when in a seated position. Prolonged sitting with a straight lumbar spine affects the proper alignment of the vertebrae and discs and in turn can possibly cause discomfort and strain.
- The backrest should have adequate padding to provide lumbar support.
14. Lumbar support adjustment
- Many lumbar supports cannot be raised or lowered and/or the amount of padding cannot be increased or decreased.
- When the lumbar support can’t be adjusted, it is difficult to achieve the proper natural curve of the spine because each person requires differing amounts of support.
- The backrest should raise and lower, and the amount of lumbar support should be adjustable either with a crank mechanism or an air pocket system.