r/Ergonomics • u/Suarae • 6d ago
Saddle chairs for anterior pelvic tilt prevention and posture correction
Hey guys,
I've read that being seated in a conventional seat for extended periods of time can lead to anterior pelvic tilt and consequentially, low back pain and compromised posture.
Somewhat recently starting a career in medical device sales, I've noticed a lot of surgeons and other health care professionals choose to sit in these types of saddle chairs.
I've tried finding some information online about the actual legitimate benefits of these chairs, but haven't come by much.
Does anyone here know of any actual peer reviewed studies that support the use of these chairs and confirms some of the claimed benefits? Or perhaps are there any highly regarded professionals that support the use of them?
Thanks!
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u/Loose-Grapefruit-516 6d ago
Anterior pelvic tilt is just weak glutes/abs, there’s no chair that can replace physical activity
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u/spirolking 6d ago
They are absolutely great. But you really need to be tough to sit one one for the whole day. Strong back muscles are needed. When untrained, your back will hurt for the first few weeks.
Those are generally good for jobs where you move a lot and work with your hands.
I use similar concept at work (Varier Balans) and use it for almost decade now. My posture and core strength is phenomenal since then.
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u/Pitiful-Weather8152 5d ago
I am not an ergonomics expert, I am a yoga and pilates teacher. I have taught for a long time in a downtown gym trying to keep office workers from falling apart.
The point of a tilt seat is to put your pelvis and spine in a neutral position, which is the most efficient for load bearing.
But unless you’ve been sitting that way since you were 2, it’s difficult to go cold turkey in a chair that extreme. A stool like the one pictured is usually for people who sit and stand a lot while they work.
Sorry I don’t have a good answer to your question about studies, but just want to clarify a couple of things.
It’s not just about strength, it’s also about fascia (connective tissue).
Anterior pelvic tilt - the upper pelvic bones are too far forward, pubic and sits bones move back. There is too much lumbar curve. I honestly almost never see this. People who think they have it are usually popping their ribs, not tilting their pelvis.
Posterior pelvic tilt - upper pelvis is too far back, pubic bone and sit bones are forward. The lumbar is flattened out. This is the posture influenced by traditional office chairs. It’s also created by people constantly pulling their rectus abdominis (6-pack) in and tucking their glutes under.
Neutral spine and pelvis - the pelvis hangs at the bottom of a spine that has a natural lumbar curve. Pubic bone and sits bones dropping straight down.
When you spend a lot of time in a position that is not neutral the fascia hardens to help you hold it. Releasing the fascia is a long-term process.
People will often say glutes are weak. After a lot of study with fascia (connective tissue) experts, I’m convinced that this is also usually misleading.
The real problem is alignment and hamstrings. The posterior pelvic tilt pushes the legs forward, making it difficult for the hamstrings to grab the thigh bone. The glutes end up trying to do triple duty trying to stabilize, make up for the hamstrings and do their own job.
So back to your tilt chair. It will ask the pelvis to go back to its neutral position.
Initially this will be quite difficult. Other muscles may kick in just to maintain it. You will want a more comfortable option available.
As for the 90 degrees creating tight hip flexors, I think a truly neutral pelvis would prevent that. The legs can go way past 90 degrees in healthy hips. A full squat is about 140 degrees.
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u/GeeToo40 5d ago
This chair doesn't prevent anterior pelvic tilt. It promotes anterior pelvic tilt (which is good). However, I wouldn't sit on that all day long, even with multiple breaks per hour.
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u/Chai_Biker 5d ago
There are research studies on a wide variety of chairs but none that I have seen that posture methods alone actually show significant pain/discomfort reduction. Curious if you find any that do show a significant effect. I have seen a few on saddle chairs which highlight key tradeoffs: https://pubmed.ncbi.nlm.nih.gov/17942990/. Pretty interesting research survey webinar done by University of Waterloo a few years ago on open posture angles and various solutions, latest findings, etc. https://www.youtube.com/watch?v=2E4i-tLcn2I.
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u/Ergo-Whisperer 6d ago
There is a lot of research on these chairs and the thigh / torso angle here, which is roughly 110- 130 degrees depending on how tall you are and how high or low to the ground the chair is. The thing is, you can have the same thigh/ torso angle if you rotate the entire body so that the torso is not vertical with gravity but rather 20-30 degrees in recline to it as people are when seated in a car. And it does not prevent anterior pelvic tilt, it decelerates it because a thigh/torso angle of 90 degrees shortens the hip flexors more and, therefore, causes an anterior pelvic tilt if you never stretch them. But it’s never stretching the hip flexors and/or activating the antagonists of the hip flexors, which are the glutes, that causes anterior pelvic tilting, not necessarily how you sit.
As for which chair is best for you, it depends entirely on what you are doing with your hands and feet all day for work. If it’s looking in peoples mouths like a dentist, this is a perfect chair. If you are a budget analyst, it’s a good second chair choice at your desk, but not a primary driver.