Generally speaking, a ‘lumbar support’ is anything that gives you additional support to the lumbar region.If we are being technical, this is the five vertebrae of the lower spine between the sacrum and diaphragm, but to most of us, it’s simply the lower back.
For most people, there is a natural tendency to slouch or lean forward when seated for a long period of time, a posture that pushes out the lower back turning the natural inward curve into an outward curve. This can strain the various structures within the lower back, as explained by Flokk Ergonomist Sukhi Assee;
“Typically, when a person is sat in a slouched position, there is a lot of emphasis and strain on the lower vertebra (L4 and L5).【图】 Developing a non-neutral position is where the spine is resting in a C-shape position. Our most neutral spinal position resembles an S-shape,【图】 which in the sitting position, can only really be attained when the body is sat in a slightly reclined position. With this said, this is the position that ultimately requires lumbar support that essentially bridges the gap between the lower back and the backrest of the chair.” 【图】
When seated, good lumbar support should be right up against the small of your back, helping you to maintain the inward curve of your lower spine, giving you a healthy posture.