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Can anyone weight in on personal experience and if you felt wrist strain? As a pianist, I think the emphasis on finger-movement chording is misguided. Yes you

Can anyone weight in on personal experience and if you felt wrist strain? As a pianist, I think the emphasis on finger-movement chording is misguided. Yes you can play chords on the piano but the entire point is to minimize finger movement - send as much movement as possible to the hand, wrist, forearm, arm, and body so as to minimize local movement. The reason is because if you try to do everything with your fingers, you increase your odds of getting tendonitis. Using a device that is designed to localize movement just to the fingers - through chording no less - strikes me as completely backwards ergonomically. I see the benefit for those that already have movement limitation, but not really otherwise.

saidajigumi 12y ago
Using a device that is designed to localize movement just to the fingers - through chording no less - strikes me as completely backwards ergonomically. That's a good point on chording mechanics, and useful to compare with Douglas Engelbart's piano-like chording keyboard[1]. Also, if the current design permits minimal movement precision-grip use (vs. crossing into power grip), it may not be too bad. The tricky design challenge of the Twiddler is that it's intended for portable, handheld use. E.g. I met Steve Mann using an earlier Twiddler rev. some years back as part of his then-current cyborg rig. Perhaps it's best to look at this device as another design compromise for a portable keyboard, instead of a desktop keyboard replacement. I wouldn't necessarily want to write a novel on my phone, for similar suitability-to-purpose reasons. [1] http://www.loper-os.org/wp-content/mw/motd_ui.jpg http://www.loper-os.org/wp-content/mw/motd_ui.jpg [2] Image in [1] via http://www.loper-os.org/?p=861 http://www.loper-os.org/?p=861
Procrastes 12y ago
I spent some time working with an early model Twiddler many years ago for a prototype we were building for an industrial application. I loved the idea and was able to get to a pretty decent speed with it, but it was really hard on my wrist. I would not recommend it for constant use. I've since developed some tendinitis and occasional trigger finger (all unrelated to Twiddler use), and I can say it would be a terrible idea for me to try to use one now as gripping makes it worse.
tenfingers 12y ago
Around ~6 years ago I was intrigued by the idea of using a regular midi keyboard as an input device. I was having some RSI issues, and was looking for alternatives. I'm not a professional pianist, but I play both pianos and keyboards. Any regular midi keyboard doesn't have key shadowing issues, so it's very easy to implement chording mechanics. I remember I was only vaguely aware of stenotyping, and certainly didn't know about plover back then, so I just tried some random approaches. The first issue with chording keyboards is the tradeoff you make between the amount of keys in a chord required to perform all permutations readily available in a typing keyboard. You can, optimally, pack all permutations only using ~10 keys, but you might require to perform either 6 key chords (3 keys per hand simultaneously), introduce sequences, or introduce trigger delays. Now, while doable, doing a 6-key chord was quite hard for me. I couldn't remember all the required permutations, and it also required to setup some quantization in order to detect the chords correctly. Quantization in turns imposes an upper-bound on CPM you can attain. Using more space with smaller chords (a larger set of 2 octaves with ~3-4 keys per chord) was easier for me, but the regularity imposed by the chords (jamming the required keys at the same time) was still unnatural. I tried to setup some different mechanics, using a sort of tree dictionary where the keys enters the branches. An approach that worked well was to map the frequent character tuples in adjacent keys. Performing CDE, CDF, DEF, EDC combos would result the vowels, which were mapped repeatedly at other locations using the same musical intervals. Typing with this system felt much more "music style": infrequent letters were mapped sparsely on the keyboard, with vowels available in every octave. You could move left-to-right to type. It's also much easier to press keys in _fast_ sequence than trying to perform a perfect chord timing, or at least that was my impression. I didn't need any quantization this way. Still, for anything but text (ie, programming), a regular keyboard felt so much faster. I remember attaining ~30 wpm or so before giving up entirely. I wish I had investigated some chord/phonetic based system, but I'm not sure how much that could've helped with regular programming.
- dllthomas 12y ago
  As I mentioned elsewhere here, I had a similar experiment (around that same time, I think :-P). What I found worked pretty well was what I called "partially chorded" - where chords in the lower octave determined a mapping in the upper. This eliminates worry about simultaneity and allows one-character-per-keypress responsiveness while still exposing tremendous representation (8 choose 3 times 8 is 448). I found it surprisingly usable in my test application, grouping keys by a fairly cursory analysis of what was likely to go together - minimizing changes of map seems desirable. I never got around to implementing a keyboard driver for it, so it was only available in my test application. I don't think I have the code available anymore, unfortunately - it's something I've always been meaning to revisit.
colin_mccabe 12y ago
I don't have any personal experience with the Twiddler. But I have read a lot about computer-based repetitive strain injury and how to avoid it. Dr. Pascarelli's book is a really good resource here. Normally the advice to "minimize finger movement" is really intended to protect your wrists, not your fingers. If you need to hit a key, but you avoid moving your hand and instead move your fingers, you will be stretching your wrist. If you consistently bend your wrist to the left or right (radial deviation or ulnar deviation) to reach notes, you may get carpal tunnel syndrome. This is basically an inflammation of the soft tissue surrounding the nerve that passes through the "carpal tunnel," a circle of bone in your wrist. The same thing happens when using a flat computer keyboard, and for the same reasons. This is why the correct keyboard posture is the V-shaped one, and the correct way to reach keys is to move your hand, not stretch your wrist. There are keyboard designs that can (almost) completely avoid ulnar and radial deviation. For example, the SafeType, a vertical keyboard, is a lot easier on the wrists. It's shaped roughly like an accordion, with the keys on both sides. This eliminates the temptation to bend your wrists to reach a key on the other side of the keyboard. The vertical "handshake" position is also a lot less stressful on the wrist than the flat keyboard one. There are finger issues that can come up if you strike the keys with too much force. These are especially a problem on the ultra-shallow (low travel) keyboards that Apple and other manufacturers are pushing now. In general, though, I would expect a design that only required finger movement to be much easier on the body than a traditional design, PROVIDED that the keys used were good quality, high travel keys. (This is a very important "provided" since a lot of keyboards nowadays are absolute garbage!) I'm curious if any research has been done on the ergonomics of chording keyboards. If not, perhaps research on RSI issues with trumpets would be a good proxy? In general, trumpet players don't have to move their hands, but only their fingers while playing. On the other hand, trumpets have a lot of vibration, which tends to exacerbate RSI issues.
- whoisterencelee 12y ago
  I have been looking around to see if there is high travel key switch which I believe is key to a good chording experience, something in between a piano key and a keyboard key. The trumpet should be a good model for the perfect chording experience. I have played the trumpet years before (in high school) and I recall that there wasn't much strain to the waist or finger. Is there any professional trumpet players here whom can share some experience in regard to the strain at high playing speeds? The location of the strain? Where the limitations are?

saidajigumi 12y ago

Using a device that is designed to localize movement just to the fingers - through chording no less - strikes me as completely backwards ergonomically. That's a good point on chording mechanics, and useful to compare with Douglas Engelbart's piano-like chording keyboard[1]. Also, if the current design permits minimal movement precision-grip use (vs. crossing into power grip), it may not be too bad. The tricky design challenge of the Twiddler is that it's intended for portable, handheld use. E.g. I met Steve Mann using an earlier Twiddler rev. some years back as part of his then-current cyborg rig. Perhaps it's best to look at this device as another design compromise for a portable keyboard, instead of a desktop keyboard replacement. I wouldn't necessarily want to write a novel on my phone, for similar suitability-to-purpose reasons. [1] http://www.loper-os.org/wp-content/mw/motd_ui.jpg http://www.loper-os.org/wp-content/mw/motd_ui.jpg [2] Image in [1] via http://www.loper-os.org/?p=861 http://www.loper-os.org/?p=861

Procrastes 12y ago

I spent some time working with an early model Twiddler many years ago for a prototype we were building for an industrial application. I loved the idea and was able to get to a pretty decent speed with it, but it was really hard on my wrist. I would not recommend it for constant use. I've since developed some tendinitis and occasional trigger finger (all unrelated to Twiddler use), and I can say it would be a terrible idea for me to try to use one now as gripping makes it worse.

tenfingers 12y ago

Around ~6 years ago I was intrigued by the idea of using a regular midi keyboard as an input device. I was having some RSI issues, and was looking for alternatives. I'm not a professional pianist, but I play both pianos and keyboards. Any regular midi keyboard doesn't have key shadowing issues, so it's very easy to implement chording mechanics. I remember I was only vaguely aware of stenotyping, and certainly didn't know about plover back then, so I just tried some random approaches. The first issue with chording keyboards is the tradeoff you make between the amount of keys in a chord required to perform all permutations readily available in a typing keyboard. You can, optimally, pack all permutations only using ~10 keys, but you might require to perform either 6 key chords (3 keys per hand simultaneously), introduce sequences, or introduce trigger delays. Now, while doable, doing a 6-key chord was quite hard for me. I couldn't remember all the required permutations, and it also required to setup some quantization in order to detect the chords correctly. Quantization in turns imposes an upper-bound on CPM you can attain. Using more space with smaller chords (a larger set of 2 octaves with ~3-4 keys per chord) was easier for me, but the regularity imposed by the chords (jamming the required keys at the same time) was still unnatural. I tried to setup some different mechanics, using a sort of tree dictionary where the keys enters the branches. An approach that worked well was to map the frequent character tuples in adjacent keys. Performing CDE, CDF, DEF, EDC combos would result the vowels, which were mapped repeatedly at other locations using the same musical intervals. Typing with this system felt much more "music style": infrequent letters were mapped sparsely on the keyboard, with vowels available in every octave. You could move left-to-right to type. It's also much easier to press keys in _fast_ sequence than trying to perform a perfect chord timing, or at least that was my impression. I didn't need any quantization this way. Still, for anything but text (ie, programming), a regular keyboard felt so much faster. I remember attaining ~30 wpm or so before giving up entirely. I wish I had investigated some chord/phonetic based system, but I'm not sure how much that could've helped with regular programming.

dllthomas 12y ago
As I mentioned elsewhere here, I had a similar experiment (around that same time, I think :-P). What I found worked pretty well was what I called "partially chorded" - where chords in the lower octave determined a mapping in the upper. This eliminates worry about simultaneity and allows one-character-per-keypress responsiveness while still exposing tremendous representation (8 choose 3 times 8 is 448). I found it surprisingly usable in my test application, grouping keys by a fairly cursory analysis of what was likely to go together - minimizing changes of map seems desirable. I never got around to implementing a keyboard driver for it, so it was only available in my test application. I don't think I have the code available anymore, unfortunately - it's something I've always been meaning to revisit.

colin_mccabe 12y ago

I don't have any personal experience with the Twiddler. But I have read a lot about computer-based repetitive strain injury and how to avoid it. Dr. Pascarelli's book is a really good resource here. Normally the advice to "minimize finger movement" is really intended to protect your wrists, not your fingers. If you need to hit a key, but you avoid moving your hand and instead move your fingers, you will be stretching your wrist. If you consistently bend your wrist to the left or right (radial deviation or ulnar deviation) to reach notes, you may get carpal tunnel syndrome. This is basically an inflammation of the soft tissue surrounding the nerve that passes through the "carpal tunnel," a circle of bone in your wrist. The same thing happens when using a flat computer keyboard, and for the same reasons. This is why the correct keyboard posture is the V-shaped one, and the correct way to reach keys is to move your hand, not stretch your wrist. There are keyboard designs that can (almost) completely avoid ulnar and radial deviation. For example, the SafeType, a vertical keyboard, is a lot easier on the wrists. It's shaped roughly like an accordion, with the keys on both sides. This eliminates the temptation to bend your wrists to reach a key on the other side of the keyboard. The vertical "handshake" position is also a lot less stressful on the wrist than the flat keyboard one. There are finger issues that can come up if you strike the keys with too much force. These are especially a problem on the ultra-shallow (low travel) keyboards that Apple and other manufacturers are pushing now. In general, though, I would expect a design that only required finger movement to be much easier on the body than a traditional design, PROVIDED that the keys used were good quality, high travel keys. (This is a very important "provided" since a lot of keyboards nowadays are absolute garbage!) I'm curious if any research has been done on the ergonomics of chording keyboards. If not, perhaps research on RSI issues with trumpets would be a good proxy? In general, trumpet players don't have to move their hands, but only their fingers while playing. On the other hand, trumpets have a lot of vibration, which tends to exacerbate RSI issues.

whoisterencelee 12y ago
I have been looking around to see if there is high travel key switch which I believe is key to a good chording experience, something in between a piano key and a keyboard key. The trumpet should be a good model for the perfect chording experience. I have played the trumpet years before (in high school) and I recall that there wasn't much strain to the waist or finger. Is there any professional trumpet players here whom can share some experience in regard to the strain at high playing speeds? The location of the strain? Where the limitations are?