Turning a simple task chair into an ergonomic chair

Greetings Instructables Community!
 I have an issue finding a nice ergonomic chair for my desk at home. I'm currently using a task chair that looks like this mildly crude cartoon (blue chair with fuscia burst).
I was thinking of disassembling it, using the back rest and the seat to make an ergonomic chair, much like this one (the kneeler with the chappy gent on it).
Or I could save myself some trouble from building the frame from scratch and make a chair like this (the black office chair-esque kneeler).

So, any tips? I've been turning it around in my head for months and any suggestions would be greatly appreciated. I guess I don't want blood clots in my calves. Thanks!

- Jules

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koontzman6 years ago
Here are some design specs with URLs, and one myth-buster re: knees bearing weight: kneeling chair is a type of chair for sitting in a position with the thighs dropped to an angle of about 60 to 70 degrees from vertical (as opposed to 90 degrees when sitting in a normal chair), with some of the body's weight supported by the shins, from http://en.wikipedia.org/wiki/Kneeling_chair A number of recent studies have confirmed Mandal’s work, with evidence suggesting that an angle of 110° or greater between the trunk and thighs reduces the pressure on the spine by as much as 35%, from http://www.kneelingchairs.com.au/evolution-of-kneeling-chairs/ One mis-perception regarding kneeling chairs is that the body's weight bears on the knees, and thus users with poor knees cannot use the chair. from http://en.wikipedia.org/wiki/Kneeling_chair
Koosie7 years ago
hhmmm, I very often fall asleep on my office chair (same as picture 2) and when my last one did that (picture 1), I wasn't very happy.  :-<

None-the-less, It shouldn't be to hard to convert, maybe you can just bend the "arm" down that bends up for the back-rest.  Cheaper chairs should just be a single piece of metal, I've had one of those.

If you look at the arm in picture 1, if you took that out, turned it upside-down and put it back, the knee-rest would be in an upwards postion.

I think the easiest way would be to get hold of the cheapest chair that you can find, butcher it and then see what happens.

If you do, make an Instructable for us! :->
mrjoancroft (author)  Koosie7 years ago
"maybe you can just bend the 'arm' down that bends up for the back-rest"
I was staring at my chair last night before bed thinking this exact thing. True story. Good call!
It's going to be a big project so I've been considering making it an instructable as well :].
The construction of the chair itself (pic 2) is simple enough, so I should be able to break it down and play with the parts while still being able to reassemble it in its original form. Thanks Koosie for your input!
Anytime.  Just don't blame me if the chair breaks and impales you! ;-)
Goodhart7 years ago
Well, the one you have pictured looks simple enough to make with some sturdy tubing, and if you have the means to bend it; my biggest problem would be in making it the proper size.

But, if you have that worked out also so that it will fit you, I don't see many difficulties with "building" it.....but it might be more difficult to turn an office chair into one of those (unless you will just be using the cushion and headrest). 

Personally, that "ergonomic" seat looks terribly uncomfortable, but then, I have knee problems and supporting myself like that would make them hurt worse.  
mrjoancroft (author)  Goodhart7 years ago
I'll probably end up re-upholstering the seat and backrest with foam and such (to build up the firmness and shape); it's likely that I'll have to experiment to get it the right size. I wonder what I could use as the bar from the seat to the knee rest. You've got a point with the sturdy tubing.
My lower back has been giving me jip and since I work online, it's the best option to keep my circulation in good shape and stave off the back pain. An ergo chair best fit for you would probably be some lumbar support as opposed to the kneeling position. Thank you for your input :)
Yeah, that third one you have pictured doesn't support the back well. 

Right now, where I work is struggling to get me positioned so I can sit and type for long periods of time without:
 #1:  hurting my shoulder  (moving the keyboard to a tray under the table eliminated my needing to lean forward)
#2: hurting my lower back (we're still working on this one)
#3: no stress on the kness (this one is pretty much solved at this point). 
The ergonomic chairs are the devil, because I have a bad knee I don't notice myself slowly putting a lot of pressure on my hip joint, which hurts an awful lot later on...

Though adjusting it to fit me would help, it's my mothers chair, I just make use of her office occasionally...

Also it takes most of your attention span to posture yourself effectively on them until you get used to the idea... 
Yeah, I think I will just sit "upright" like I have for 51 years   LOL