True confessions of Hank Austin, Ergonomist:
When I do an office ergo evaluation I work my way down asking about the discomfort in different body parts. If it comes up that the client is having sciatica issues we begin to talk about their “seats”. I always ask about their office and car seats and specifically ask if they are contoured. I ask if the seats go up on the edges. When they do, there is the distinct possibility that that contoured edge is pressing on their sciatic nerve. People who sit with their legs spread out a bit can have their legs go over the contoured chair edge.
I once asked a chair designer from a major manufacturer why they contoured the edges. He said because it looked good. Any of you have a different take on that (I do know that there are contoured chairs with force mapping strategies and “hugging” the body features as well)? Anyway, I told him about the sciatic issue and that the contours (on this one chair) can twist the leg thus twisting the hip in the socket potentially also causing hip problems. His face fell, and he did not say much to that. The key is that all of these features are great- they just need to fit the individual employee or they can actually cause harm.
For my clients with major sciatic issues I suggest that they try to get a car next time with a flat seat and do the same with their office chair. In the mean time I suggest they get a pillow like a stadium seat (any color you want) and it can lift your legs above the contoured edges.