In simple terms it is the part of your ergonomic office chair which provides support to your lower back region and this is often an area in which people suffer back pain in. A good ergonomic office chair will have lumbar support which is adjustable and sometimes dynamic to ensure comprehensive support.
One of the best examples of an ergonomic office chair with dynamic lumbar support is the SIHOO Doro C300. It has a dynamic support which is heighted below which automatically adjusts so that it constantly provides support as you move to different postures and positions, and it is this feature which has made it one of the most popular ergonomic office chairs available in the UK.
Although dynamic lumbar support is the most sophisticated, the other types of support that you will come across are: fixed lumbar support and adjustable lumbar support.
Fixed lumbar support is the most basic and as the name suggests the support is fixed and therefore if it does not suit your body there is not much that you can do about it. Due to this lack of flexibility most of the ergonomic office chairs available have moved to some kind of adjustable lumber support.
In this regard there are a number of different adjustments which are available so you need to check before you buy. The two main adjustments are a height adjustment and an adjustment which moves the lumbar support forward and back. The height adjustment sometimes comes through adjusting the whole backrest up or down, but this is not ideal. You need to look for a lumbar support which can be adjusted independently of the backrest.
One of the best ergonomic office chairs with adjustable lumbar support available in the UK is the SIHOO M57 which comes with an excellent lumbar support which is independently adjustable for height and also in towards your spine so achieve the precise support that you need.