computer display ergonomics

[jacobolus]

tp4tissue, myself, and some others have been discussing computer display ergonomics in the context of bickering about what display resolution is worthwhile to pay for (and let’s confine discussions about resolution to other threads and not drag them in here, thanks), but I thought it would be useful to start a separate thread about display placement, since I started doing some online research about the subject, and some of the links that popped up seem contrary to the “conventional wisdom” I had heard before.

The basic idea of these links is that computer display should be placed substantially lower than usually recommended, and displays should be tilted substantially back at the top. This is a very different position than the one I usually see advocated, with the top of the screen at eye level or slightly above, and the display relatively straight up and down. (And quite different from the setup I see people using in any office I’ve ever been in.)

This seems to be the first source that got linked around in ergonomics circles sometime in the late 1990s:

“New Visual Considerations At Computer Workstations”
http://www.allscan.ca/ergo/vangle2.htm


http://www.allscan.ca/ergo/dscreen.htm


“The influence of computer monitor height on head and neck posture”
http://burgess-limerick.com/download/a17.pdf

http://office-ergo.com/eyestrain-neck-pain/


“Eye Strain, Neck Pain and Monitor Placement (Conventional Wisdom vs Ergonomics Evidence)”
http://ergoweb.com/eye-strain-neck-pain-and-monitor-placement-conventional-wisdom-vs-ergonomics-evidence/

It seems like there was a bunch more research about this “low monitor” placement in the ~2000–2005 timeframe. I haven’t read through the relevant research papers yet, but I’ll put a link in here if I find anything especially notable.

[RED-404]

I like to have the top edge of the monitor about 2" above eye level when gaming. I find looking down at a monitor when playing FPS games, especially console ports "low FoV" or flight sims to be really disorienting. As for work I really couldn't care less about monitor location as long as I can get up and take a walk or work on my feet from time to time.  I can say the few times I have worked at a workstation that had the monitor under the surface of the desk or semi recessed it felt strange if the keyboard didn't also have a substantial negative tilt.

[PieterGen]

I scanned, very quickly, one of the documents. It has a good point in that it seeks a position for the neck that gives the least stress, which does not by definition mean a 100% upright position.

A point I'd like to bring up is that the human body is not really built for sitting still, but rather for moving. So perhaps some variation in the 'neck tilt' might be healthy ?

[tp4tissue]

I scanned, very quickly, one of the documents. It has a good point in that it seeks a position for the neck that gives the least stress, which does not by definition mean a 100% upright position.

A point I'd like to bring up is that the human body is not really built for sitting still, but rather for moving. So perhaps some variation in the 'neck tilt' might be healthy ?

god I h8 the human body..  wish I had a cylon body.. fffff..



On the serious side...  Even if you sit like in that picture.. You couldn't do it for very long, because your back and ab muscles has to keep extremely tense for you to be so "upright"


Which is why they keep telling kids to sit straight, but they can NEVER do it..   because it's tiring..  and you'll naturally want to slouch..  or slid ur butt forward..


and when you do either of ^^^ those things,  it'd be impossible to have a downward angle machine.


So the confounding variable in that diagram is not neck....


 

[davkol]

Nah, it has more to do with the Western civilization and lack of muscles.

[jacobolus]

PDF available from http://scholar.google.com/scholar?q=related:GTzl9slz9iEJ:scholar.google.com/&hl=en&as_sdt=0,5

This “optimal gaze angle” is very different from the way most people position computer displays, and much closer to the angle we use when e.g. reading a book, or working with our hands.

[jacobolus]

I’ve been trying a setup like this for the past day or so, and so far I quite like it:


When I get the chance, I’ll try shifting the base of the main monitor arm to the side of the desk, so I can push the display a foot further away, to see what difference that makes. (In general though, I don’t much mind having it ~2.5 feet from my face; my eyes aren’t feeling strained, etc.)

[jacobolus]

Here’s a (paywalled) 2006 paper that seems to support the idea that a “downward line of sight” display has some longer-term health benefits:
http://www.sciencedirect.com/science/article/pii/S0169814106000035

Abstract:

This study investigated the long-term effects of vertical monitor placement in 150 ordinary offices workers. Random assignment was used in creating a high line-of-sight (HLS) group (n=75) and a downward line-of-sight (DLS) (n=75) group. The line-of-sight to the midpoint of the screen was 15° below horizontal for the HLS-group and 30° for the DLS-group. Measurements were taken at set-up and again 12 months later. Significant differences, favouring the DLS-group compared to HLS-group, were found for subjective symptoms, oculomotor capacity, and self-reported sick leave. The DLS-group exhibited flexion of both the neck and back about 5° more than the HLS-group. No differences were found for work-related diagnoses, traditional clinical measures, or electromyographic activity. The results correspond with previous laboratory findings and give additional empirical support from natural work environments to the beneficial effect of DLS in visual display unit (VDU) work.

And another one from 2003:
“VDU work with downward gaze: the emperor's new clothes or scientifically sound?”
http://www.sciencedirect.com/science/article/pii/S0169814102001920

Lower monitor placements, with gaze angles to the centre of the screen 30–45° below the horizontal line are proposed as an alternative to higher monitor placements advocated by prevailing guidelines. A scientific basis for this proposition has been established within a comprehensive theoretical framework, founded on an ecological systemic approach to vision. A review of the literature shows reduced visual strain and a strong tendency towards reduced symptomatology in subjects working with downward gaze. Increased musculoskeletal load is not evident in m. trapezius, while a clinically insignificant increase might be present in some other neck and shoulder muscles. Research studying subjective preferences is inconclusive at present. The evidence indicates that lower monitor placements result in less strain on the total network of muscles involved in visual display unit (VDU) work.

[RED-404]

The only way I can really see this working well is if something "for most people it will have to be something" forces you to keep a good posture. The local county library has the monitors under a glass desk and you have to sit up to see the monitor if you slouch the monitor will blur out due to some sort of film on the underside of the glass that limits viewing angle.

[jacobolus]

A chair like the capisco chair pictured that supports at least 5-6 different postures (like a normal office chair, like a saddle chair, like a high saddle-seat stool, backwards with either normal or saddle type posture using the backrest as forearm armrests, reclining and optionally using the backrest to rest the elbows, sideways) makes it much easier to avoid getting stuck in one bad slouch. Especially nice with a height-adjustable desk like the one pictured, and display(s) on easily adjustable arms, since those sitting styles work best at different chair heights, and since standing up occasionally is also nice.

I think poor posture is partly a result of bad chair design (combined with way way too much static sitting). Car seats, airplane seats, movie theater seats, most office chairs, most school desks, etc. are really quite bad.

[hoggy]

A few years ago, it was the fashion for newsreaders to have a monitor below the glass desk (back in the day of CRT screens).  But much like today, they have such technology and never use it.

[Lanx]

i had the downward sight monitors back in my computer lab in the mid 90's.

Looking back on it, it felt really "trollish" but did not feel uncomfortable.

[JackMills]

This “optimal gaze angle” is very different from the way most people position computer displays, and much closer to the angle we use when e.g. reading a book, or working with our hands.

This is interesting information to approach a display setup. I prefer to switch between sitting and standing desk, and I find that the traditional setup for a sitting desk doesn't translate well when standing. When I stand I tend to look down because it lightens the tension in my neck, which seems to be similar to these optimal gaze angles.

Another topic I would like to ask about, multiple monitors, how do prefer to setup these? I always sit in front of one screen with the other next to it. This is far from ideal, because I tend to turn my head a lot. Optimal would be to center yourself to both screens and maybe even to place the screens at a slight angle so that they form a V or a wedge (I hope this is understandable, because I cannot find a proper explanation at the moment)

Jack Mills I am working with my laptop today and I just took it of its stand trying to achieve a similar setup as jacobolus has. It just occurred to me that this is a more normal setup for laptops, but you always put it on a stand because that's how you have been thought a good position should be like.

[jacobolus]

Another topic I would like to ask about, multiple monitors, how do prefer to setup these? I always sit in front of one screen with the other next to it. This is far from ideal, because I tend to turn my head a lot. Optimal would be to center yourself to both screens and maybe even to place the screens at a slight angle so that they form a V or a wedge (I hope this is understandable, because I cannot find a proper explanation at the moment)

I typically have my main work on one screen, and if there’s another screen, it gets miscellaneous/auxiliary stuff like documentation, tool palettes, extra data displays, or chat windows. I don’t spend too long continuously typing
on the second display; I’m either glancing at it briefly or else looking at it with my hands off the keyboard.

I am working with my laptop today and I just took it of its stand trying to achieve a similar setup as jacobolus has. It just occurred to me that this is a more normal setup for laptops, but you always put it on a stand because that's how you have been thought a good position should be like.

Yeah, I’ve been thinking about this too. I think slightly higher up than the laptop display is usually a bit more comfortable, and also further back. But a laptop might not need to be elevated quite so much as people often elevate it when trying to be “ergonomic”.

[JackMills]

I typically have my main work on one screen, and if there’s another screen, it gets miscellaneous/auxiliary stuff like documentation, tool palettes, extra data displays, or chat windows. I don’t spend too long continuously typing
on the second display; I’m either glancing at it briefly or else looking at it with my hands off the keyboard.

I try to do the same, however I notice that I tend to start typing on the second display. Even if I have a good tool to make windows switch displays easily, I tend to keep my head in a turned position too long. And bad habits die hard, I will have to take time to reprogram myself.

Yeah, I’ve been thinking about this too. I think slightly higher up than the laptop display is usually a bit more comfortable, and also further back. But a laptop might not need to be elevated quite so much as people often elevate it when trying to be “ergonomic”.

My keyboard tray is about 10 cm lower then my desk surface, which seems to be good at the moment to test the downward gaze with my laptop screen. As I am working with an external keyboard the laptop is automatically set back further. It seems to be an enjoyable setup.

[jsquared]

I've found I have a lot of trouble finding the best angle for my elbows, and the arm padding is a huge factor for me when Im picking out a chair because of it. As I am working or playing games for an extended amount of time I find myself resting more and more on my elbows, though, and ruining my posture Maybe higher armrests would help out?

[jacobolus]

Mini update. So I haven’t kept quite the same setup as the picture I showed upthread, but I have had my displays tilted maybe 15° back for the last 4–5 months, with the top of the display at about nose level. It’s great, more people should try it.

[rsadek]

I've found I have a lot of trouble finding the best angle for my elbows, and the arm padding is a huge factor for me when Im picking out a chair because of it. As I am working or playing games for an extended amount of time I find myself resting more and more on my elbows, though, and ruining my posture Maybe higher armrests would help out?

The ergo folks often suggest no armrests. Maybe try dropping them all the way down and not using them for a bit?

They also say if there's a lot of weight on the elbow, something else is set up wrong: seat height, chair height, etc. Can you say what causes you to put so much weight on the elbows?

[rsadek]

This downward angle thing is interesting. I find that working on a laptop on my lap really strains the neck. Maybe that's too low?

[Keymonger]

Yikes... looking at this image makes my neck hurt.

Anyways I've been thinking about this a bit and I think the best setup might actually be something dynamic. Some kind of electric monitor stand that shifts the monitor around in height so your neck won't constantly be in the same position, although most of the time it would be near the range of 'eye level condition'.

[jacobolus]

Yikes... looking at this image makes my neck hurt.

In practice, it’s about the same neck position you’d have reading a paperback book held out in front of you in one hand. Much better than what most people do when looking at their cellphones.

The picture there is a bit misleading though (or I’d even say wrong). You don’t actually want to tilt your whole head/neck forward by bending your spine, with your head way out in front of your body. Instead, you want your neck/spine to stay tall and straight, but rotate your head forward around its own center, lowering your chin without leaning forward, keeping the center of mass of your head over your body. It’s not an uncomfortable position to hold, and doesn’t cause much static muscle load.

[njbair]

Well on that note... Does anyone WTB some monitor risers?

[rsadek]

Fwiw I really like the humanscale monitor arms. They are great and allow me to change it up so I don't have to keep the same position.  If it's not comfy or I feel strain, I just move the monitor and it stays put. The counterbalance is great.

[jacobolus]

I’ve been pretty happy with these arms:
https://www.massdrop.com/buy/Ergotech-Freedom-Arm?mode=guest_open

[rsadek]

I�ve been pretty happy with these arms:
https://www.massdrop.com/buy/Ergotech-Freedom-Arm?mode=guest_open

 Those are real nice. I like it

Here's the one I referred to

http://www.humanscale.com/products/product.cfm?group=M2

I love em. They can be found for less and some employers have discount arrangements for employee purchases. Costly, but less than we blow on boards and keycaps!

[timofonic]

This downward angle thing is interesting. I find that working on a laptop on my lap really strains the neck. Maybe that's too low?

I moved my HP 2475w 24" display and yes, it feels better. But I also need a not-****ty armchair, the good one got broken and zero money these days  :/

I'm tired about laptop usage. I really hate the laptop keyboard and feeling so uncomfortable in "lazy mode" (typing at the bed), I would kill to hack a mechanical one on it and improve the ergonomy of it on all use cases.

It's a MSI with Intel COre i7 7500HQ one, I would replace the battery to a big one. I don't want a low power laptop because I use EDA stuff and others run the apps really slow, I would sacrifice weight and have 4-6H full-speed autonomy desdpite it might add 3-4KG (but I would love to use the battery as PSU for external devices, including the soldering iron and any circuit on PCB/breadboard).

I might open a thread about that, I'm researching about it too.

[awakened]

I've got a 40' monitor and I think i'm way too close to it, arms length away approximately, I haven't gotten any neck pain or the such but I feel like my eyesight is going to the crapper.

[-musubi]

I’ve been pretty happy with these arms:
https://www.massdrop.com/buy/Ergotech-Freedom-Arm?mode=guest_open

I'm definitely planning on getting these arms once I get a bigger desk