One of my favorite mesh chairs happens to be a fairly inexpensive one sold at a popular office store. Unfortunately, there are two deficiencies in the chair that develop after a few weeks of sitting for long hours. I'm not sure if it's my anatomy that weakens or components of the chair, but here goes:
1) The edges of the curved lumbar support starts digging into the back. Over time this translates into lower back pain and muscle spasms.
2) The mesh material stretches out resulting in loss of bottom support. When this happens the seat starts to sag. Online reviews mention this as "the seat turning into a hammock"
Step 1: Padding the Back Support
Buy a bleacher cushion from the local dollar store or Walmart. Wedge it between the mesh back and the lumbar support. I used this configuration for years. The foam rounds out the edges of the lumbar support but over time, the shape of the support still ends up digging into my back. Recently I came up with an improved modification detailed in the next step..
Step 2: Flattening the Lumbar Support Curve
The problem with the lumbar support is that the curve is angled too tightly. Rather than softening the edges, the support can be flattened by wedging an object BEHIND the outside curve. My office has an abundance of Amazon packaging bubbles, and they just happen to fit perfectly. Anything about the same size should work.. a t-shirt, towel, rag, whatever. The flattened lumbar modification is far more hospitable to my kidneys.
Step 3: Fixing the Seat Hammock
Buy a square of upholstery foam ($7 at your local Walmart) and stuff it under the seat. Work it in through the front underside opening little by little. Tugging from the edge openings help it into place. Surprisingly, this is harder to accomplish than one would expect. In the end, persistence pays off. The seat will be far more supportive for your butt and your back. Over time, the seat may still sag. If you look closely, you'll notice I shoved magazines underneath the cushion to fix this. Keep stuffing magazines into there until seat cushion stiffens to the level desired.
This concludes the Hyken chair hack. Hopefully these tips save your seat, your back, and your bank account from having to buy replacement chairs every few years.