Great to see ergonomics issues getting attention on HN. When you ignore (or are unaware of) ergonomic issues for years, you can get into serious trouble (like I did). I had been programming for over 10 years without any problems (and without paying any attention to ergonomics), and 7 years ago I got Repetitive Stress Injury (RSI) really bad. I tried many things to get rid of it, but it was very hard to get rid of. The RSI got so bad that I thought I had to give up programming all together.
Fortunately I managed to find a combination that worked for me. The most important component was using a break program that made sure I took breaks to rest my arms and hands, and to do some exercises. I also switched to an ergonomic keyboard and mouse. I am now completely recovered, but it really made me realize that we need to pay attention to ergonomics.
In addition to what I mention in my post, I am now also using a height-adjustable desk (like the OP). It's really good to be able to switch between sitting and standing. If you are like me for the first 10 years of my career (i.e. ignoring ergonomics), consider paying a little bit of attention now, otherwise it may become a problem later on.
I was in a similar position. I started using computers at a young age (around 7) and by my early 20s had debilitating RSI. At one point I couldn't hold a mouse for much more than 15 minutes. I would wake up in the morning with both of my arms completely numb. I "solved" that problem by going through probably $5,000 worth of ergonomic keyboards and chairs.
I still experienced severe wrist pain, finally peaking out in 2010 where the pain and numbness was continuous. I assumed incorrectly that I had irreversible nerve damage.
Unrelated to this I started doing upper body strength training. Besides going from not having done a pushup in years to doing hand stand pushups I can now sit at my computer for 12 hour stretches with zero pain. By the way, this was about 3 weeks of training before the pain vanished. Over the past few years I've had brief pain a handful of times, that went away quickly.
Now whenever I start developing any sort of problem I revert whatever piece of my lifestyle that is out of balance back to its normal state. I wish I had figured this out a decade ago.
Eh, many many people get debilitating RSI whe they first start typing a lot in college or wherever, and grow out of it in a couple of years regardless of therapy technique.
It's crazy really to use an ordinary keyboard. It's basically the same as when the keyboard was invented. At that time there was some justification for having to fit your hands to the machine. Now there is none really. The Microsoft one is pretty cheap. If I have to use an ordinary keyboard now it feels fine for the first five minutes but then I start to feel what it really is - cramped.
I feel the same way about QWERTY -- I've been typing in Dvorak for ten years now, and on the rare occasions I have to go back to QWERTY on a full-size keyboard it feels like I'm tying my fingers into knots.
In addition to height adjustable desks, there is some interesting tech chasing this need. Lumoback has developed a bluetooth enabled device to track and help maintain good posture: www.lumoback.com [disclaimer: the founders are friends]
Well spotted! Just a few minor edits. But I do think it's important to get the message out - it's so easy to ignore, and then you can end up with real problems and real pain for a long time.
Both links are about posture thus making his comment relevant to both. If you mention something to someone concerning something you've done, do you never mention it again even with a different audience? The bigger question is "Why shouldn't he say the same thing?" It's not like he's spamming the front page with links. He has an experience that might be applicable to people who did not see the first link (like me, I come to HN multiple times a day but did not see the previous link or comment).
Pointing this out seems akin to hanging out with a friend in multiple social settings and when he tells a story you have heard before but the group hasn't, you stop him and tell him he's told that before.
Better that he repeats himself a lot then to mention it only once. It was the first time I saw this comment and as somebody who's developing aching wrists and fingers, I'm glad I came across it.
Maybe the smartest and most talented person I ever met.
Born in 1895 is eastern Europe and as a child never went to school, missed many meals, feared for his safety, and emigrated to the U.S. alone at age 11. Married my grandmother 6 years later and raised 6 children in a 2 room flat during the depression. His entire adulthood: painted buildings with lead-based paint, installed asbestos, smoked cigarettes, and lived in Pittsburgh back when the skies were black with soot all day long. Worked his ass off and suffered and died from emphysema at age 80.
Me:
I write software in an air-conditioned office, eat delicious healthy food every meal, work out at a fancy gym, and have more money than I know what to do with.
Sure we have it pretty easy but you are making a wrong comparison here. You can't compare the life and health standards of the early 1900 with our health and life standards (at least in the developed world). Things moved for the better not only for Software developers.
The right comparison is between you and someone who has achieved the same education/social level in the same period of time.
Not necessarily. His grandfather, while breathing and possibly ingesting toxins his entire life, did one thing most programmers do not do: exercise a lot. Yes, I saw the "work out at a fancy gym" part. There is a huge difference between going to the gym a few times a week and doing labor like his grandfather did.
My own grandfather did hard manual labor his entire life and drank whisky like a fish until he was in his late 60's. Chewed tobacco his entire life. When he was 88 I saw him working in the back yard and he had muscles that I didn't have at my prime (in my 20's). He died at 95.
I walk 4 or more miles a day, 7 days a week, some up steep hills. That's my commute, on the days that I go to work, my exercise when I don't. I really don't expect that I'm simulating my grandfather's level of exercise, but I hope it does something to get me to 95, in as perfect health as my grandfather was when he died.
You really want to measure life expectancy for people entering working age to avoid measuring infant mortality. Those numbers sound like they don't take that into account.
In logic, providing even one counter-example is considered refutation. Its tempting to do that with social/medical fields too. You're right its not statistically significant, but its absolutely, certainly data. An organism CAN survive extreme conditions, even thrive.
For example, claims of necessary action based on real statistical data are unwarranted. The existence of populations that thrive in the so-called 'unhealthy environment' do show there are more variables at work. Who's trumpeting "we should all work like 1800's laborers for good health!"? Nobody, but not because its not true. Because we're lazy-ass modern narcissists who want a quick fix.
Did you mean to say "emigrated to the U.S. alone at age 21"? If that wasn't a typo, then your grandfather has my sincerest respect. Doing that, and getting married at 17, certainly indicates a lot more maturity than the average teenager today.
The title is hyped and inaccurate. It's not software development that's bad for health. It's the bad sitting posture and that's not essential to software development.
It's true that the title might be a little hyped. However, the most interesting thing I learned was that improving sitting posture alone will not alleviate standing posture problems.
I've been doing CrossFit for a year now. I couldn't articulate enough how it has improved my posture and general fitness. There isn't one particular thing about CrossFit, rather the whole. I'd recommend to anyone.
Second that. I used to have constant shoulder issues with my mouse arm. As long as I'm being active with my shoulder I'm good. CrossFit, yoga, slack lining, it doesn't matter what you do, but not being physically active is a detriment to your well being. Everyone owns it to themselves to live healthy!
For those who want to get started, but don't know how checkout Nerd Fitness: http://www.nerdfitness.com/blog/ I have no ties, only that it's a great place to start learning about how to take care of yourself.
Technically it's free. Plenty of websites with all sorts of helpful information about programming. But paying to be a part of a box and a small community while working in a competitive environment is worth money. To me at least.
About ergonomics, there's several things I don't do (and you shouldn't as well)
- Don't use your laptop without a 'docking station' for long. Strain to your neck, back and hand/wrist. A mouse/keyboard and support to keep the screen at eye level does wonders
- Don't use a 'moving mouse'. Apple magic trackpad is great. Trackballs are great as well.
- Even better, limit the use of a pointing device (if your job allows it, e.g. for anything graphic this is difficult). Today I do most of my work with keyboard alone, even web browsing (the exception is clicking links and buttons)
Clicking links - In firefox, activate 'search for text when i start typing' (options->advanced), then just type the text of the link and press enter. If the link is something frequently occuring on the page like 'reply' then type something right in front of hit then press tab and then enter. :)
>> Don't use a 'moving mouse'. Apple magic trackpad is great. Trackballs are great as well.
I have used Apple Magic trackpad for almost an year and I started having severe discomfort when I my middle and ring finger are stretched. I was not resting my palm properly and that probably contributed to the issue. I switched to an evoluent mouse (http://www.amazon.com/Evoluent-VerticalMouse-Regular-Right-V...) and it got better very fast (in couple of weeks).
Is the reasoning behind avoidance of the 'moving mouse' simply because you move your wrist a lot when mousing? I find that with the dpi cranked way up on my mouse it takes considerably less motion to click on things than with a trackpad. Moving my mouse all the way across a 1080p screen is essentially a finger twitch. I've tried the vertical mice before too, but they definitely take some getting used to.
Any ideas for file manipulation with the keyboard? With long Windows paths there's no way a CLI is going to be faster than moving files around with Explorer, which is not very keyboard friendly. I've looked at alternative file managers and haven't found anything that sticks.
What's not keyboard friendly about explorer? I find it very easy to work with, actually one of the most keyboard friendly programs i have! Arrows and typing for navigation, (shift+)tab for jumping from tree to file list(without mouse you actually get used to working without tree-view, i have mine always hidden), ctrl+c/v/x = duh. F2=Rename, Ctrl+shift+n = new folder. Alt+Up = Up, Alt+left/right = back/forward. Alt+D = Navigation bar(with autocomplete!). Ctrl+E = Search. Alt+P = Preview, Contextmenubutton alone = right mouse button (i'm surprised many people don't know about this button), this contains almost all the remaining things you need that don't have a dedicated hotkey, and even this list can be navigated quickly with the keyboard, for example Contextmenubutton+R = Properties, Or N for SendTo.
Frequently working with two different folders? open a new window(Ctrl+N) and dock one window on each side of the screen with win+left/right. Then simply alt+tab between them, or use the win+nr if you have it docked on your taskbar.
The only thing i'm missing for keyboard navigation is a hotkey to toggle navigation bar on/off and a more sleek autocomplete, such as visual studios or quicksilver.
My problems with shoulder and wrist pains all originate from stressful projects. When you sit entire days with your muscles tense, over and over again, that is when problems start to occur.
I can not connect my problems to bad ergonomics, because the way I was sitting in front of my computer all the way up until university years, those were far from ergonomic positions. But if you are relaxed and have fun, you automatically vary your posture and position.
Ergonomic chairs and keyboards are only one way to make you be able to endure your stressful work condition a bit longer when you sit there stressed trying to meet deadlines and whatever problems you fight with. The pains will show up, only later.
Myself, I often try to wake up from the work, feel my body and if I'm actually stressed. Take a deep breath, see if I can let my arms hang loose and relaxed. If I feel that I'm actually sweaty and have a high pulse, then I need to go for a walk. A good manager that I can bring this up with helps.
Also a bit of a fuck-off attitude also helps: My health is so much more valuable than the job and its compensation.
I can't read the article as the server is not responding, but from what I gather it's about RSI, carpel tunnel, etc. I'd like to present an alternate viewpoint and suggest that RSI is not caused by physical action, such as typing on a computer keyboard or bad posture, but rather it's root cause is psychological (with the understanding that physical things are happening, but they are controlled by your mind).
I suggest reading "The Mindbody Prescription" by Dr John E Sarno. Here is one of the better summary of the ideas (in Word doc format): http://www.rsi.deas.harvard.edu/handout.doc
Personally, I have been pain free for over 10 years thanks to this.
Same here. It was really quite bad, I had nerve pain 24/7, numbness, soreness, you name it. In fact, when I first learned about TMS, it got worse. I was unemployed, and going through very bad depression, and despite ceasing all computer use, I was still in constant pain. I think my subconscious was just sadistically causing me pain.
Anyways, the symptoms disappeared quite suddenly during an LSD trip, weirdly enough. It was one of the most blissful days of my life, just relaxing in nature with some good friends.
Still unemployed and depressed, but at least I don't have horrible pain to deal with every day...
Good tips. Also I think it's really important to get up and walk around every few hours if you're sitting.
If your boss won't allow you to do this then seriously consider quitting. Your personal health is way more important than some job where you're taking orders from someone who won't even give you 10min to walk around.
Just to toss down what's worked for me in case it helps someone else:
I was on the brink of RSI (numbness in the fingers) until I changed to a Kinesis Advantage keyboard, and a trackball mouse (thumb movement). Some lingering issues were cleared up with exercise -- mostly wrist rollers and grip training. I still use a flat keyboard & normal mouse occasionally without issue.
Back pain is a little battle, but a good chair (Steelcase Think) is night & day if you're sitting for more than a few hours at a time. Generally I do the best here when I'm not being lazy about my exercise. Squats, deadlifts, weighted sit-ups, etc. all help a ton.
The Kinesis Advantage works fairly well for me on the Mac. You can change key layouts on the keyboard itself (as opposed to the OS) if something isn't to your liking.
There is one thing that I missed though: play, pause, ff, volume and brightness controls on the keyboard. I haven't worked out a solution for volume and brightness, but play, pause, and ff I do with keyboard shortcuts through Quicksilver.
Just wanted to clarify: it looks like you _can_ set different key bindings for screen brightness in the Mac's preferences. I can't find similar for volume controls though...
I used to be, and the Kinesis works great there. It is a super configurable keyboard. You can swap the definition of any two keys (make enter -> backspace, caps lock -> escape, etc.)
The only OS that I've had issues on is Windows. There's a USB3 driver issue there. But I don't program in Windows, so doesn't affect me.
Anyone have experience with eye issues? I've seen Ophthalmologists and my vision is perfect, but I am constantly in discomfort/ border line pain and it's been like this for over 2 years. I know it's due to computer use but various "therapies" don't seem to be making a difference. Would love to hear your experiences.
Edit: I've gotten some great responses below. In case it helps anyone here is what I do to help myself:
* lower the brightness of displays as low as possible
* make sure I am looking down at any screens
* fish oil supplements
* I wear these ridiculous yellow tinted motorcycle sunglasses (motorcycle sunglasses are padded, trapping moisture)
I mitigated this issue buy purchasing a pair of reading glasses (+0.5 diopter; I have perfect vision). When I feel eye strain set in, I pop on the glasses, which sets the focal point of my monitor further away, allowing my eyes to relax a bit. Vice-versa if I'm already wearing the glasses.
That sometimes happens to me, after doing 100+ hours/week, for some months straight :). The best solution is to get away of the computer, as much as possible.
Other things that can help:
- Have good ambient light. Don't look at monitors in the dark.
- Adjust the monitor backlight/bright to as low as possible, while it still looks good.
- Take short rests often. Every ~40 minutes, get away of the computer. Look at a distant point in the horizon for a couple of minutes.
I've struggled sometimes too. Try increasing your font size. My vision is excellent, but I think staring at tiny fonts increases strain on your eye muscles or something.
Also, as monitors have gone up in resolution over the years, pixel density has increased, shrinking the default font size from what is appropriate for the eyes.
Lowering the brightness is not always beneficial. In fact, the opposite can be true. Brightness is usually controlled electronically by rapidly switching the backlight on and off. Therefore, lowering the brightness can increase the amount of flicker, which is imperceptible but still implicated in strain. Try turning the brightness all the way up, which will minimize flicker. If it's too bright, wear sunglasses and see if that helps.
>I've struggled sometimes too. Try increasing your font size. My vision is excellent, but I think staring at tiny fonts increases strain on your eye muscles or something.
This one has been the big one for me. My vision is not excellent, and the coke-bottle glasses are a testament to that, but I'm just about 20/20 with them on and I still end up feeling weird after staring at a screen for too long. I tend to use fonts about three steps up from normal size and I never have problems anymore.
Big fonts and 1920x1200 (Retina) on a 15" screen makes for a lot of workspace and it looks good. :)
It'd be great if many apps actually let you do that. Finder on OSX - how do increase the font size there? IntelliJ - how do you increase the font size there? I can increase the font size of my editing area, but not of the tree area with files in it.
Have been using macs for the past few years, and this is my one of my biggest bugbears - font sizes are often very locked down, and I end up having to shift my position or squint.
>Finder on OSX - how do increase the font size there?
While browsing a folder, do a secondary click (right button on Magic Mouse or two-finger click on a trackpad), open "Show view options". A popup window will appear; select your desired font size (I think 16px is the maximum). Then click on "Use as defaults" and all folder and file labels will use the same font size.
Do your eyes also feel very dry? If you already have dry eyes, starring at computer will make it worse. I had similar problem for a while, until I started to force myself to drink lot of water at the office, and humidifier at home.
Of course, this is just one of the possible causes.
I definitely agree with this! Hell I use it to bring the temperature of the colors down to match the lighting during day and night. It's a brilliant program.
Along the same lines, I had bad posture for a long time, and always wondered what to do about it. "Stand up straight" was too simplistic, and "do yoga" was too broad.
He describes how to analyze posture (once you learn, you see signs of bad posture -- aka muscle imbalances -- in nearly everyone: people at work, at the store, even professional athletes), and then he lists dozens of simple exercises that work to restore your muscle balance. And at some point you'll do an exercise that engages a muscle you haven't used in years, and when that happens, your body feels FANTASTIC!!
The books are just the tip of the iceberg, too. There are Egoscue clinics around the country that can take you to advanced levels.
I had arm trouble while typing for a while, and fixed it.
Trigger point therapy was the big one. I had a few spots in my right forearm that were messed up. The therapist jabbed them. It hurt terribly, but then my arm was much better.
I'm strong enough that I can now do the same thing to my own arm if I feel it getting tense. Armaid is also a great tool for this.
On my left arm, I had something worse. Found a physiotherapist who did MAT (muscle activation technique) and he managed to work out some adhesions in the upper part of my left hand.
If you have pain, go see a relevant therapist. There's a decent chance you have some kind of muscle trouble.
Note: I saw several non-useful therapists. For muscle adhesion problems, results should be pretty quick. I only needed 1-2 sessions with each of these guys.
I can only speak from limited personal experience, but I don't know any programmers/developers with carpal tunnel syndrome (though they may have other issues), but I know plenty of other office worker friends who do have it. I've never had it despite all the time I spend at a laptop or a computer.
For my own part, I'm not someone who crunches at the keyboard for sustained periods of time, and I regularly switch up between mouse and trackpad and trackball. But I wonder if for non-hackers, the reliance on the mouse and, in my opinion, extremely inefficient computer operating methods, is a factor in how a standard office worker can get CTS even though they spend less time at a computer than your average professional developer.
I've known a couple with carpal tunnel syndrome. But even if you exclude that, just about every programmer I know over the age of 25 has had some kind of wrist or hand pain at some point. Probably due to the amount of typing and mousing involved. (I fully predict the rebuttal to be that these people are doing it wrong.)
In most cases there seems to be no long-term damage, and the injuries in question are probably not terribly serious. It's just harder to rest one wrists or fingers than it is (say) one's knee, ankle or shoulder.
I developed a horrible pain in my right wrist at the age of 20, during my first software development internship. Any motion I made with the mouse was torture. I had to start using the mouse with my left hand to do work at all.
The pain is gone now, but I take ergonomics quite a bit more seriously. I'm considering getting a split keyboard, although it breaks my heart to have to get rid of my clicky das.
I have one and love it. You have to be willing to invest time in it though: it took me 2 weeks to get up to full speed, plus I spent a bunch of time remapping the thumb keys to my liking.
I got a Kinesis about a year ago after developing wrist pain, and second the recommendation. It took me a full month to get back up to speed on it but now my wrist pain is gone. The keys feel nice too. My only complaint is that it makes it difficult to type one-handed while I'm eating, but I really shouldn't be eating at the computer anyway. :)
Something else I tried was putting my mouse on a slant away from the keyboard so that the radius and ulna were not as pronated. This helped, but my mouse kept sliding off the incline. Ideally I'd like something at an angle in between a standard horizontal mouse and the vertical ones like the Evoluent. It seems there are a few new models on Amazon since I looked last--may have to try one. My pain is more in the arm than the wrist, so fine wrist motion is more important than being completely vertical. At some point it may just make sense to 3D print a mouse of the appropriate shape...
For me, mousing has been consistently and terribly painful. I bought a right-handed Evoluent mouse (I am right handed) and it worked wonders, until a period of particularly intense mousing, at which point I bought a left-handed model.
Now, I primarily use the left-handed Evoluent mouse. During periods of intense mousing, if I start to feel pain, I'll switch to the right-handed Evoluent mouse for a week or two.
You mentioned wanting a mouse which put your hand at an angle in between a standard mouse (horizontal) and the Evoluent mouse (vertical). Is there a particular reason for this?
I ask because I've found the Evoluent to be incredibly comfortable. Besides which, a vertical orientation most closely emulates the position your hands would be in when you are anatomically at rest (standing, with your hands hanging down at your sides).
As much as I love the Evoluent mouse, I still feel that eliminating mousing from my computer use is the Right Way to address mouse related pain. Treat the root cause, not the symptoms, as they say.
I basically use keyboard shortcuts for everything. The two parts of using a computer which I found most difficult to control with a keyboard were web browsing and window resizing / management.
For web browsing I stumbled upon Chrome + the Vimium extension. It has non-chording key bindings for switching tabs, moving around on the page, following links, copying (yanking) text, etc. Basically, Vimium adds Vim-like keybindings to many common browser tasks. Find it here: http://vimium.github.com/
For window resizing and management, I use Moom (it's a Mac application). It is fantastic. You can setup key bindings to resize a window to a preset dimension, among other things; but that's what I use it for primarily. I have 3 key bindings that I use all the time: 1) full screen, 2) two thirds on the left side of the screen, and 3) one third on the right hand side of the screen. Moom is here: http://manytricks.com/moom/
I've also become aware of Slate for window management on the Mac, which looks amazing, but is a tool of the large investment / large payoff sort, and I just haven't had much free time lately. Slate is here: https://github.com/jigish/slate
I use one daily and really like it, although its made of cheap plastic. The $99 list price is pushing it, you can probably find one on ebay for ~$30. I got mine for free at the Humanscale showroom when I went to look at their chairs.
Maybe you are right. When I was 20 or so, I also used the computer a lot, not so much for programming yet, but for this and this. So I did use the mouse much more than I do now. However from time to time I felt issues with my hands.
So I even bought this heavy Logitech Natural Keyboard, I think things improved a lot. Anyway, from time to time I still had minor issues.
Being 28 now, working since some years fulltime as developer with normal keyboards, I hardly have such issues anymore. Although I have to admit that I pay attention that I get up from time to time. But I am definitely no ergonomics ideal. Half of the time I sit like depicted on the picture on the OP's link and in the evenings even worse when I hack at home on my laptop.
When I was working as a Japanese to English translator, I started getting carpal. Switching to Dvorak keyboard solved the problem, with the added bonus that I could type 10 WPM faster after six months of getting used to it.
I am in my early 20s but I already get wrist and elbow pain from mice. Trackball is better, but still causes pain. The keyboard has never been an issue. My workstation is now 100% keyboard controllable. Vimperator and XMonad were key to this transition. Now I just have back problems.
Don't improve your sitting posture: stand instead! We know about posture, but we're rubbish at it because humans are lazy! More scientists say you should stand or treadmill while working, and I definitely concur.
I was getting a lot of the negative side effects of sitting at a computer all day over the past few years, and I made several changes that have really helped, including: hiking once to twice a week, switching positions regularly between sitting at a desk, reclining on a couch, and standing, and making sure to move around regularly through the day, avoiding those long periods of sitting still for hours. The constant headache and random pains I was having have faded.
Not only software developers sit in desks. Most employees in my company aren't software developers. I'm glad this article is one about the physical problems of sitting incorrectly all day, as oppose to the increasing "this isn't good for your health articles", describing software development as a deadly stressfull depressing job that isn't for everyone. If your health is deteriorating due to software development, YOUR DOING IT WRONG! :)
The article isn't loading, but on a related note I just had a brief discussion about standing desks on my site, and finally bought a Geek Desk. If you are wanting to buy one I list 3 good brands here, and also my warnings about them (below) if you are tall.
I'm so excited for it to come in the mail it makes me sick.
Another option which allows one to sit and keep the core engaged are things like a the swopper chair or exercise/swiss/balance balls. Because of the nature of the subtle movements, your hip flexors are engaged often (as long as you don't completely slouch on them).
FWIW, my biggest wrist and arm problems came from using a "sticky" mouse. As the mouse and pad gets "old" and dirty, there's often a lot of friction when moving the mouse.
The mouse should move very easily. (try lightly touching it with you little finger)
If you're worried about sitting all day, drink more. Water, tea, coffee, anything really. You'll have to go to the bathroom more, that WILL get you out of your chair.
I'll let everyone make their own determinations about milk -- I would be a skim-only person, and then only sparingly. But if asked for a recommendation, I would say limit milk intake to much less than water.
Sugarfree soda = the devil.
Sugarfree juice -- the real stuff -- is probably ok in moderation. However, a good chunk of the health value in fruits comes with the pulps and skins and pithes and the like. Fruit juice is really just a portion of the healthy nutrients one can get from fruit. Moderation is the key, as the glycemic load of fruit juice, even just the squeezed stuff, can really be high.
Never mind what all this stuff does to one's dental health, which is harsh (even milk is a culprit.) I simply can't encourage those of us who sit at desks in this job to drink enough water. 64 oz is the recommended minimum a day, but I think it should be higher.
Caveat: this works for me, so your mileage may vary.
When these discussions come up people often mention the Steelcase Leap as an equal. Find a local store that sells them and try them all out. For me the major distinguishing point was the lower back support. The cheaper Aeron version would dig into my back while the Leap had some flexibility to it. I'm not sure if the higher end Aeron chair would have been superior with the contouring lower back support but I'm glad I got the Leap over the base Aeron model.
No, you don't need expensive chairs for coding, you don't need to "sit down well" because it is not possible or good for you. Do sit for hours in a "correct" posture and you will discover that your body tries to move constantly from it (blood circulation needs your pressure points to change constantly or bruises will appear).
Instead of buying expensive things go buy experts book on the area of posture, or better, go talk with expert people in the field. Books like this helped me in the past(I had pain in my back years ago) :
http://www.amazon.com/Steps-Pain-Free-Back-Solutions-Shoulde...
But I assert you that in the area you live there is already lots of good people that could help you. In my area I found a martial arts expert(that won Olympic gold medals when young) that could identify wrong postures from an eye shot.
PS: I code mostly standing up and with a high stool.
I do way prefer the Aeron over the Mira. The back support on the Mira is better but... Once I've used the Aeron's pellicle mesh (both in the back and on the part you sit on), I simply cannot go back to a chair which doesn't have a pellicle mesh.
The Aeron is a bit cheaper and you can find quite some at a bargain price if you're in the U.S.
I forked that and $300 or so on a Topre-switch based keyboard (an HHKB Pro 2 but YMMV, some people prefer bigger keyboards -- I'd rather move my hands / fingers as few as possible). Probably that a real split / symmetric keyboard like the Kinesis Advantage or the Maltron are even better (they're using Cherry Mx switches, no Topre).
Fortunately I managed to find a combination that worked for me. The most important component was using a break program that made sure I took breaks to rest my arms and hands, and to do some exercises. I also switched to an ergonomic keyboard and mouse. I am now completely recovered, but it really made me realize that we need to pay attention to ergonomics.
I've written up my story in more detail here: http://henrikwarne.com/2012/02/18/how-i-beat-rsi/
In addition to what I mention in my post, I am now also using a height-adjustable desk (like the OP). It's really good to be able to switch between sitting and standing. If you are like me for the first 10 years of my career (i.e. ignoring ergonomics), consider paying a little bit of attention now, otherwise it may become a problem later on.