How do I make my desktop arrangement ergonomic?

[HungerMechanic]

Okay, I've been using a computer desk from the 1990s. It's obsolescent, but I haven't found anything better to upgrade to, because I'm not sure what qualifies as an improvement.

To understand my setup, picture a flat desk. Now, put a raised monitor shelf at the back of that desk. Then, flank that monitor shelf with some taller shelves at the back.

There is a keyboard tray under the desk itself.



You can see that it was designed for CRT 4:3 screens, not large wide-screen monitors. So now I have the monitor sitting forward on the desk itself, rather than on the monitor mount at the back of the desk.



Anyway, the biggest issue for me, ergonomically speaking, is that the keyboard is safely in a below-desk tray, where it poses no ergonomic issues, but the mouse is on the desk itself, above the keyboard tray. It's on the desk because:

1. It can't fit on the keyboard tray, since I have a full-size keyboard there.

2. The armrests of my chair at the sides would get in the way of using a lower-positioned mouse. [They're designed for use with a desk-positioned mouse.]

Now, I doubt that this is the best ergonomic arrangement. The mouse should probably be on the same plane as the keyboard, right? I actually have the keyboard tray tucked into the desk somewhat, so that's it's almost like a 65% board [the F-keys are hidden under the desk.] This is a usable arrangement, but I am still leaning forward to use the mouse.

I guess I have two options:

a.) Put everything on the desk. This would probably necessitate moving the monitor back, though, and getting rid of the shelves that are in its way. And it would necessitate a smaller keyboard. At least the chair arm-rests would be aligned with everything.

b.) Put everything on the tray. This would also mean a smaller keyboard. And I would need a chair with adjustable armrests, or no armrests, I guess.

Or, I could get a new desk. But for what ideal arrangement, I'm not sure.

[Venaros]

I'm not really an ergonomics nut, but it sounds like you've got a lot of the points right, I would definitely recommend putting your keyboard and mouse on the same level. If you want to keep the numpad, I'd highly recommend getting a dedicated numpad, you can save a lot of mouse space, and move it away when you don't need it, and keep your arms closer together. Is your chair height adjustable? I would be putting your chair height and keyboard/mouse height so that your elbows will be at a 90 degree angle.

Other ergonomic points to consider: What is your eye level relative to your monitor? Your eye level should be around the top of the monitor. What angle are your wrists at when you use the keyboard?

[HungerMechanic]

Any future builds will be TKL or smaller, so I'm not overly worried about numpad. I'll use a separate one, maybe even on the left.

The chair is the biggest problem. With the fixed armrests, my elbows are at an approximately 90-degree angle on the desk surface, but go lower than that to reach the keyboard.

Like 100/80-110/80.

The eye level to the monitor, at least, is correct. It's situated so that my eyes are looking at the top 25% of the monitor.

[Findecanor]

Could you detach the arm rests from the chair, or are those what are keeping the chair together?

[superbia]

c) http://xahlee.info/kbd/trackball_index.html

[HungerMechanic]

Yeah, I really should have invested in a chair with no armrests / adjustable armrests.

I bought a new chair recently, but it doesn't have adjustable armrests.

Why do 'ergonomic' 'office' chairs have fixed armrests? Are all desks the same height? No keyboard trays?

EDIT: Thanks, superbia. I have a cheaper trackball, but will be investing in a SlimBlade if a compact keyboard arrangement works.

(So far, I've been thinking of getting a 75% keyboard instead of a TKL. This would allow greater space for a trackball in the keyboard tray, or even a mouse.)

[nevin]

Corner or L shaped desks are just tricky. They are designed more for space saving then for ergonomics. I have never been fond of keyboard trays either, although i've used a number of different ones in work environments over the years. Never enough room for a mouse, even if using a 60% (unless you have the keyboard way to the left, but then, that's not optimal either). Trays are fine if you use a trackball. You can either try to find a shorter/lower desk or a taller/higher chair. I'm in a similar situation right now, the table i'm using is just slightly too tall for the chair that i have. I have also removed the arms from my chair, was a simple two screws for each arm.

[RSanders]

... Why do 'ergonomic' 'office' chairs have fixed armrests? Are all desks the same height? No keyboard trays?...

A "real" ergonomic office chair will be fully adjustable to include the arm rests.  Unfortunately, those chairs tend to be associated with a "real" price (Herman Miller Aeron, for example).   The problem with  readily available desks being a specific height is one of economics.  Companies tend to produce products in a size that fits the majority of who they think will buy their product.  As long as you have the money, however, desk height is no issue as you can have one custom made or you can go with one of the relatively expensive fully adjustable desks currently available.  A properly adjusted chair, in my experience, usually ends up with a desk height that, in terms of ergonomics, is either too high or too low for a particular user.  In my case, I compromise and have my chair just slightly lower than it really should be so I can tuck the armrest mounted keyboard partially under the desk while using the secondary keyboard or completely under the desk when leaving for the day.  You could always raise your current desk on risers you build yourself or carefully cut your desk down to the appropriate size, if necessary.  I avoid the issue entirely by having my primary keyboard mounted directly to the arms of my chair with all of my monitors adjusted so they are at the correct viewing height relative to my chair. If I don't need to use the trackball, I will keep my arms down and supported by the chair arms with all typing done on the chair-mounted keyboard.  If support for your forearms is an issue when using a mouse up on the desk itself, you could consider using a product such as the Ergo-Rest which follows your arm around in a single horizontal plane within a set range of movement.  I use two, one for each arm, when my work involves constant switching between typing and pointing devices.  For work of that nature, it is a bit tedious to have to remove my right hand from the chair-mounted keyboard, locate the Ergo-Rest, rest my arm on the Ergo-Rest, use the mouse, reverse process when going back to typing...you get the idea.   It is simply easier to lean slightly forward at not quite the correct height, ergonomically speaking, and use my secondary keyboard and trackball on the desk itself, as long as both my arms are supported by Ergo-Rests.  For primary keyboard work, I just push slightly away from the desk, lean back very slightly at a very comfortable angle with my feet flat on the ground, and type away.  Incidentally, I use an L shaped desk, but not by choice.  It is what came with my office.  The L shape is actually very conducive to a multi-monitor setup such as the one I use.   I sit facing the inside angle of the "L" with my secondary keyboard resting on either side of that angle (image below). I would not wish a keyboard tray on anyone. Very generally speaking, your lap makes a better tray.


Regarding your original post, this is how I would recommend proceeding:
1) Adjust your chair optimally to your height, i.e. sitting up straight, hip joint 90 degrees, knee join 90 degrees, feet flat on ground just barely supporting the weight of your legs. 
2) Adjust chair arms optimally to your arm length, i.e. shoulders relaxed, elbows bent 90 degrees, top of hands in line with top of forearm with minimal bending in the wrist. If this is  not possible, seriously consider getting a different chair.  Your chair should conform to you, not the other way around.  If the chair arms can be removed and the desk height is acceptable relative to your chair, seriously look at a product such as the Ergo-Rest to support the free weight of your arms while typing or using the mouse.
3) Once your chair is squared away, see how everything is relative to that. Is your monitor still at the correct height relative to your eyes? How much do you have to contort to accommodate the location of your keyboard and mouse? An adjustable tray may fix your issue, or not.  Based on your description of your arms (assuming your shoulders are also relaxed and not hunched up to allow for the height of the arm rests) relative to the keyboard while on the tray, your situation may indicate placement of the keyboard on the desk next to the mouse as a possible solution.  You may have to compromise some in this regard to get everything as close to "just so" as possible in terms of ergonomics. Your goal is to have your body as close to the ideal ergonomic position while seated in a correctly adjusted chair and to have everything you need to access ergonomically positioned relative to this.  It will take experimentation on your part as everyone is different.

[typo]

First of all, YMMV on this. I would tell you to use the same exact setup I have. It is going to cost you around $10,000 though. I do not like "ergonomic" keyboard trays whatsoever. They all "bounce" around as you type just leading to injuries. I have a desk just like yours and find it to work best. However mine is a powered sit stand desk. I feel you should invest in the same. Than Get a "loaded" Herman Miller Embody Chair. Next, a Topre keyboard of your choosing. I warn that if you choose the "RGB" model it will require major modifications to be any good. All the others are fine out of the box, so long as they are not Type Heaven or Leopold. Finally pick up a Elecom  M-XPT1MRXBK thumb trackball, it is like nothing else and not at all like Logitech. Make sure everything is adjusted properly for you. I like a bean bag mouse wrist rest to put my hand at the height of the thumb ball and a hardwood or leather keyboard wrist rest. OH, get an Eneloop Pro battery for the Thumb ball. There is an entire ergonomic workspace. Just a few things. You my want to throw in a good Vesa monitor stand if your display accepts Vesa mount and does not already have a fully articulating display. Assuming you are right handed, put the display all the way on the right rear of the table and tilt it towards you. Adjust it's height correctly. If you are left handed display on left and you require the left handed version of that Thumb ball as well. Not much too it but easily 10 grand. Than you can upgrade your PC and get an Eizo Coloredge display as well. Bringing it more into the $40,000 range then. If you have a budget in mind, just completely disregard all of this then and whatever will be will be

[HungerMechanic]

Thanks for the in-depth responses, RSanders and typo.

I don't think I'm quite ready for RSanders' spaceship solution! Although it is clearly more optimized than most solutions.

You're both right that the chair and desk height is the real weak point here. I should have "gone big" on the chair, as adjustable armrests would solve a number of problems.

I had tried to optimize my desk setup to proper posture in the chair, but it's not ideal. Not without a desk than can elevate. I've considered something like what typo is describing, and may have to go for that some day.

In the meantime, I should adjust my new chair when I set it up, and see how the desk and monitor position need to be modified. I have also been seriously considering a Realforce R2, but I don't think I'll get one unless KBDFans produces the Topre 9009 set again. I knew I'd kick myself for not ordering that.