Why Seat Depth Adjustment Matters
If you have read our page on What To Look For When Buying An Ergonomic Office Chair you'll have seen listed as one of the five key features of any ergonomic office seat is to have it be seat depth adjustable.
Many people aren't even aware that such a feature exists on office chairs, let alone why it's so important.
Just think about when you go shopping for trousers or jeans, most stores offer a choice of 3 or 4 leg lengths for your size, or an oversize leg length that can be altered to your needs.
And it really is no different with office chairs, one size doesn't fit all. Unless you are fortunate enough to have a leg length that corresponds with what the manufacturer designed his fixed seat depth chair for, then you are going to find that this type of seat will always be a compromise.
You may find that a fixed seat chair appears to have been made for your leg length and still doesn't feel comfortable to sit in. Why is this?
Well, it's actually quite simple, the measurement that is most critical is your upper leg, the part that is sitting on the chair's seat.
If your upper leg measurement doesn't suit the chair's seat depth you still won't be comfortable in it, even though your leg length seems right for it.
A few years ago I had a client who told me that she had suffered six years of discomfort in her office chair and observing her sitting in her chair it wasn't difficult to see why.
Her legs protruded way beyond the seat's fixed pad. She explained that she had extremely long femoral bones and estimated that this part of her leg overhung the edge of her chair seat by 8''
By simply changing to a seat depth adjustable chair she was able to adjust the seat's front to back dimension to the correct length for her needs. As a result she managed to find comfort at work for the first time in many years.
So, if you have a fixed seat and you find that your legs seem to be protruding more than 2-3 inches beyond the end of the seat pad, consider a sliding seat chair.
Seat depth adjustment on office chairs is still nothing like as common as it should be, manufacturers are slowly introducing it, generally on high end seating products.