Author Topic: Help a newb out - Keyboard angles  (Read 3657 times)

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Offline aya3154

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  • Posts: 70
Help a newb out - Keyboard angles
« on: Wed, 30 May 2018, 11:14:09 »
Hi guys, thanks for clicking on my thread
I'm relatively new to KBs in general so I appreciate all input

I'm thinking of designing a keyboard case for the Zeal60 out of a solid piece of aluminum, I'm thinking of making the base all in one piece (inclusive of feet)
Was wondering what angle the case should be inclined at and what kind of difference each one makes ?
« Last Edit: Wed, 30 May 2018, 11:34:27 by aya3154 »

Offline grimmold

  • Posts: 8
Re: Help a newb out - Keyboard angles
« Reply #1 on: Wed, 30 May 2018, 16:15:57 »
Note: I'm not a doctor and actually just looked most of this up to write this, so please take it with a grain of salt.

From: How does the hand work?
(I'd recommend this article to anyone to get a glimpse of how amazingly designed our hands are)

"The long flexor and extensor tendons of the forearm muscles are partially surrounded by protective layers, called tendon sheaths. They produce a fluid that acts as a joint lubricant to lessen any friction caused by movement. The tendon sheaths can become inflamed, which may be caused by injuries or by overuse resulting from repetitive uniform motions.

Muscle tendons, nerves and blood vessels run from the forearm to the hand through a passageway, which is level with the wrist on the inside of the hand. This passageway is called the carpal tunnel and is made up of connective tissue and carpal bones. If the tissue around the carpal tunnel swells up as a result of an inflammation or an injury, the nerves may be compressed, causing pain and distortions in sensation."



If anything in the carpal tunnel of the wrist, such as tendons and ligaments, become inflamed or otherwise compress the nerves that are right next to them, the result is pain and potential injury. To avoid this, you minimize wrist use by keeping them in a neutral position, which is straight. This is impossible when 10-finger typing on a standard keyboard since your wrists are in a constant state of pronation and ulnar deviation:



From Xah Lee's website:

"The standard keyboard creates several biomechanical problems for the operator. First, the hands tend to be ulnarly deviated up to 40 (mean values of 25; Smutz et al., 1994) placing additional loading on the carpal tunnel and increasing the pressure within the tunnel as much as 13% (Werner et al., 1997). Second, to obtain a flat palm, the forearm tends to be pronated close to the anatomical limit (mean values of 76), which requires the activation of the forearm muscles (mainly pronator teres and pronator quadratus). Such tension over extended time periods can also lead to muscular fatigue. Third, to compensate for this tension, there is a tendency for operators to lift the upper arms laterally and forward, which requires the activation of the shoulder muscles (primarily the deltoid and teres minor). Again, static tension may lead to fatigue. Fourth, depending on the height and slope of the keyboard, there is a tendency for the wrists to be extended up to 50 (mean values of 23; Serina et al., 1999). Of all the possible wrist deviations, this wrist extension may be the most critical with carpal tunnel pressures increasing to 63 mmHg (for fingertip forces of 6 N), considerably above 30 mmHg, the threshold level for potential injury (Rempel et al., 1997)." (Andris Freivalds, Biomechanics of the Upper Limbs: Mechanics, Modeling and Musculoskeletal Injuries)

Then, having an inclined keyboard results in extension, as shown in the wrist motion graphic and as noted in the above quote. The solutions to these problems are tenting (pronation), having each half of the keyboard at a neutral angle for your wrists (ulnar deviation), and negative tilt (extension).

(This isn't an endorsement of this keyboard, as you'd ideally want a higher tenting angle for increased pronation reduction, but this is the best picture I've found that includes a split design, tenting, and negative tilt)


Also, standard keyboards being unsplit results in horizontal adduction, which triggers several muscles in the back and shoulders, resulting in, as we all know, pain, and potentially injury over time:



The solution to this problem, and to all of the problems I've mentioned, is a keyboard that's fully-split, tentable, and negatively tiltable.

"Such problems at a typewriter keyboard were noticed as early as 1926 by Klockenberg, who proposed that the keyboard be split into two halves, each angled 15 from the center line (Figure 10.21, included angle is 30), as well as tilted laterally down (sometimes termed tented). Furthermore, Klockenberg (1926) suggested an arching of the key rows for each half of the keyboard to better configure with the natural layout of the fingers. The lateral tilting was more specifically examined by Creamer and Trumbo (1960) with a mechanical typewriter cut into two halves and tilted at five different angles. Keying at the middle position of 44 was 5% significantly faster than at the extremes of 0 (flat) or 88 (nearly vertical). Kroemer (1964, 1965, 1972) performed a more detailed analysis by varying also the upper arm position and found that the subjects preferred a similar hand orientation of 40 for the upper arms hanging down naturally. Although the subjects preferred typing on a split and tilted keyboard over a standard keyboard, typing speed did not show any differences. Error rates, however, decreased by 39%." (Andris Freivalds)

So since you're in the design phase of your project, I strongly recommend considering more ergonomic options; though if it has to be standard, then I'd recommend making it as flat as possible. If it being somewhat non-standard is okay, then for it to be as ergonomic as possible, you'd at least want negative tilt; so if you add feet to it, add them on the side closest to you. If that's too funky, then flat it is.

This post reminds me of the user Data's avatar:

« Last Edit: Sun, 03 June 2018, 10:25:51 by grimmold »

Offline grimmold

  • Posts: 8
Re: Help a newb out - Keyboard angles
« Reply #2 on: Wed, 30 May 2018, 17:30:45 »
(Revised and merged with my original post for the convenience of new readers)
« Last Edit: Thu, 31 May 2018, 02:03:44 by grimmold »

Offline aya3154

  • Thread Starter
  • Posts: 70
Re: Help a newb out - Keyboard angles
« Reply #3 on: Wed, 30 May 2018, 23:57:48 »
Note: I'm not a doctor and actually just looked most of this up to write this, so please take it with a grain of salt.

From: How does the hand work?
(I'd recommend this article to anyone to get a glimpse of how amazingly designed our hands are)

"The long flexor and extensor tendons of the forearm muscles are partially surrounded by protective layers, called tendon sheaths. They produce a fluid that acts as a joint lubricant to lessen any friction caused by movement. The tendon sheaths can become inflamed, which may be caused by injuries or by overuse resulting from repetitive uniform motions.

Muscle tendons, nerves and blood vessels run from the forearm to the hand through a passageway, which is level with the wrist on the inside of the hand. This passageway is called the carpal tunnel and is made up of connective tissue and carpal bones. If the tissue around the carpal tunnel swells up as a result of an inflammation or an injury, the nerves may be compressed, causing pain and distortions in sensation."

Show Image
Show Image


If anything in the carpal tunnel of the wrist, such as tendons and ligaments, become inflamed or otherwise compress the nerves that are right next to them, the result is pain and potential injury. To avoid this, you minimize wrist use by keeping them in a neutral position, which is straight. This is impossible when 10-finger typing on a standard keyboard since your wrists are in a constant state of pronation and ulnar deviation:

Show Image


From Xah Lee's website:

"The standard keyboard creates several biomechanical problems for the operator. First, the hands tend to be ulnarly deviated up to 40 (mean values of 25; Smutz et al., 1994) placing additional loading on the carpal tunnel and increasing the pressure within the tunnel as much as 13% (Werner et al., 1997). Second, to obtain a flat palm, the forearm tends to be pronated close to the anatomical limit (mean values of 76), which requires the activation of the forearm muscles (mainly pronator teres and pronator quadratus). Such tension over extended time periods can also lead to muscular fatigue. Third, to compensate for this tension, there is a tendency for operators to lift the upper arms laterally and forward, which requires the activation of the shoulder muscles (primarily the deltoid and teres minor). Again, static tension may lead to fatigue. Fourth, depending on the height and slope of the keyboard, there is a tendency for the wrists to be extended up to 50 (mean values of 23; Serina et al., 1999). Of all the possible wrist deviations, this wrist extension may be the most critical with carpal tunnel pressures increasing to 63 mmHg (for fingertip forces of 6 N), considerably above 30 mmHg, the threshold level for potential injury (Rempel et al., 1997)." (Andris Freivalds, Biomechanics of the Upper Limbs: Mechanics, Modeling and Musculoskeletal Injuries)

The solutions to these problems are tenting (pronation) and having each half of the keyboard at a neutral angle for your wrists (ulnar deviation), with a tented, split keyboard accomplishing both:

(This isn't an endorsement for this keyboard, it's just a generic example)
Show Image


Also, standard keyboards being unsplit results in horizontal adduction, which triggers several muscles in the back and shoulders, resulting in, as we all know, pain, and potentially injury over time:

Show Image


The solution to this problem, and to all of the problems I've mentioned, is, obviously, a fully-split and tentable keyboard.

"Such problems at a typewriter keyboard were noticed as early as 1926 by Klockenberg, who proposed that the keyboard be split into two halves, each angled 15 from the center line (Figure 10.21, included angle is 30), as well as tilted laterally down (sometimes termed tented). Furthermore, Klockenberg (1926) suggested an arching of the key rows for each half of the keyboard to better configure with the natural layout of the fingers. The lateral tilting was more specifically examined by Creamer and Trumbo (1960) with a mechanical typewriter cut into two halves and tilted at five different angles. Keying at the middle position of 44 was 5% significantly faster than at the extremes of 0 (flat) or 88 (nearly vertical). Kroemer (1964, 1965, 1972) performed a more detailed analysis by varying also the upper arm position and found that the subjects preferred a similar hand orientation of 40 for the upper arms hanging down naturally. Although the subjects preferred typing on a split and tilted keyboard over a standard keyboard, typing speed did not show any differences. Error rates, however, decreased by 39%." (Andris Freivalds)

So since you're in the design phase of your project, I strongly recommend considering more ergonomic options; though if it has to be standard, then I'd recommend making it as flat as possible.

This post reminds me of the user Data's avatar:

Show Image


Thank you for the informative post, much appreciated
it was definitely very interesting reading up and building knowledge on the ergonomics
Alas I already have a PCB for a standard one for this project at least, rest assured if anything I'm inspired to do a split one as well but going one step at a time
& as a result I will make as flat as possible a design for this project for the ergonomics  :thumb:

Offline aya3154

  • Thread Starter
  • Posts: 70
Re: Help a newb out - Keyboard angles
« Reply #4 on: Thu, 31 May 2018, 00:01:23 »
Quote
So since you're in the design phase of your project, I strongly recommend considering more ergonomic options; though if it has to be standard, then I'd recommend making it as flat as possible.

Actually, to be as ergonomic as possible, you'd want negative tilt to compensate for the elevation of the keys. So if you add feet to it, add them on the side closest to you, and then use a separate flat wrist rest. Something like this, minus it being split and tented somewhat: 

Show Image



If that's too funky, then flat it is.

I agree ergonomically negative angles are better however yeah it might just be a bit too funky but I will give it a shot in the design process ;D

Offline grimmold

  • Posts: 8
Re: Help a newb out - Keyboard angles
« Reply #5 on: Thu, 31 May 2018, 02:27:50 »
I'm really glad it helped! Since you're open to the idea of negative tilt, you could incorporate a flat wrist rest into the design. That'd be awesome (if not really heavy :- P)! As for the tilt angle, I'm assuming you have a standard keyboard, so you could experiment with negatively tilting it until your wrists are at a really neutral and comfortable angle while typing. Anyways, have fun designing it! Maybe you could keep us updated on the process in this thread?

Offline aya3154

  • Thread Starter
  • Posts: 70
Re: Help a newb out - Keyboard angles
« Reply #6 on: Fri, 01 June 2018, 20:25:16 »
I'm really glad it helped! Since you're open to the idea of negative tilt, you could incorporate a flat wrist rest into the design. That'd be awesome (if not really heavy :- P)! As for the tilt angle, I'm assuming you have a standard keyboard, so you could experiment with negatively tilting it until your wrists are at a really neutral and comfortable angle while typing. Anyways, have fun designing it! Maybe you could keep us updated on the process in this thread?


Yup a standard keyboard for now so I will try to get a flat wrist design and neutral angled. I'll post a finished image of the CAD design when it's done but it won't be anytime soon ahah  :)) , thanks for help  :thumb:

Offline grimmold

  • Posts: 8
Re: Help a newb out - Keyboard angles
« Reply #7 on: Sun, 03 June 2018, 10:28:21 »
I was reading over my post again and realized that I, ironically (considering the original question), totally failed to address extension properly (due to my ignorance), so I redid my post to prevent others from encountering bad information. I originally wrote:

Quote
The solution to this problem, and to all of the problems I've mentioned, is, obviously, a fully-split and tentable keyboard.

No, a fully-split and tentable keyboard won't solve all of the problems I mentioned by default unless the tenting design allows for negative tilt.

I feel pretty bad for offering bad medical advice to almost 300 people, but I hope this post can fix it somewhat. Sorry to everyone that read my original post and was misinformed! If I've missed anything else, please let me know.
« Last Edit: Sun, 03 June 2018, 10:35:55 by grimmold »

Offline uncannyapple

  • Posts: 2
Re: Help a newb out - Keyboard angles
« Reply #8 on: Mon, 11 June 2018, 18:07:05 »
Quote
No, a fully-split and tentable keyboard won't solve all of the problems I mentioned by default unless the tenting design allows for negative tilt.

Does the said negative tilt result in your wrist flexed instead of just neutral? The pinky and ring finger are short enough to allow reach to only 1 more upper row.

Also what's the deal with 5 or even 8 degree positive angle in many new cases GB? It almost make the user do jazz hands already.
« Last Edit: Mon, 11 June 2018, 18:09:09 by uncannyapple »

Offline jcoffin1981

  • Posts: 694
Re: Help a newb out - Keyboard angles
« Reply #9 on: Tue, 26 June 2018, 07:00:49 »
I've noticed that my wpm have increased annd my wrists feel better with the legs flat on the board.  However, some boards are molded with an angle.  I don't think you can please everyone, but the flat or very low angle is better for wrist health.

I'm looking at my Leopold board vs the Pok3r and there is a big difference.  The Leopold has a 1-2% angle and the Poker has maybe a 4-5% angle.  It's hard to go back to the Poker after using the Leopold.  The Leopold has legs and I can change it but the Poker doesn't.
« Last Edit: Thu, 28 June 2018, 20:26:48 by jcoffin1981 »
KPB V60 Gateron Browns and Leopold Keycaps.  Poker 3 with Gateron Browns and Poker keycaps.  Poker 3 with Cherry MX Browns, ABS keycaps and white LED's.

Leopold FC660M- my new favorite, right out of the box.