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Computers and Carpal Tunnel Syndrome Studied 365

Posted by michael
from the aching-wrist dept.
pioneer writes "An article on MSNBC.com reports that a Danish study has found that computer use is not a significant risk factor for carpal tunnel syndrome. Not sure about you, but I spent a lot of time learning dvorak and kinesis to prevent just that... the 'inevitable' onslaught of RSI/carpal tunnel/etc."
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Computers and Carpal Tunnel Syndrome Studied

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  • Dutch study? (Score:5, Informative)

    by stefanvt (75684) on Thursday June 12, 2003 @09:18AM (#6180911)
    Actually the article says it's a Danish study ...
  • CTS != RSI (Score:5, Informative)

    by squarooticus (5092) on Thursday June 12, 2003 @09:20AM (#6180948) Homepage
    If the article header is accurate, then Pioneer should be informed that carpal tunnel syndrome is only an INSTANCE of RSI, and the two are not equal. It is, in fact, still possible that every single other type of RSI has computer use as a significant risk factor and not contradict this study.
  • by BreadMan (178060) on Thursday June 12, 2003 @09:22AM (#6180965)
    Says the article:

    According to the (U.S.) National Institute of Neurological Disorders and Stroke, a 2001 study conducted by the Mayo Clinic also found that heavy computer use â" up to seven hours a day â" did not increase the userâ(TM)s risk of developing the injury.

    I don't know about you, but my computer usage averages about 10 hours a day. However, I don't know if I actually type for 7 hours out of the ten, after factoring in meetings and other productivity boosters.

    I worry more about my eyes than wrists. I may not be typing 100 wpm constantly, but I am looking at my monitors even when not typing.
  • Re:Not Ineveitable (Score:5, Informative)

    by Troed (102527) on Thursday June 12, 2003 @09:25AM (#6180983) Homepage Journal
    I started using computers with a mouse when I was 12, and I've had extreme problems. I'm now using a mouse with my left hand (I'm right-handed) at home, a trackball (centered in front of the keyboard) at work. I also use a natural keyboard at work and a normal at home. If I sit extended periods of time I get a tingling/freezing feeling in my index fingers (yeah, I'm not touch typing fully) and I regulary have neck pains and pains in my upper arms.

    I seriously question this study - I've seen numerous fellow employees at various companies who have dealt with their RSI problems in different ways. (Here's one tip for managers: raise the temperature! Sitting in a cold draft only worsens things).
  • by Surak (18578) * <`moc.skcolbliam' `ta' `karus'> on Thursday June 12, 2003 @09:28AM (#6181013) Homepage Journal
    The cramping of wrists actually has nothing to do with CTS. CTS != RSI, but CTS is ONE kind of RSI, as someone else pointed out. You could have an RSI, but not necessarily CTS.

    IANAD.

  • Do what? (Score:2, Informative)

    by vbprisoner (676611) on Thursday June 12, 2003 @09:33AM (#6181057) Homepage
    Try telling this to the people (about 6) I know who have had supportive treatments and/or operations.

    It has occured to me that all these people are females in their 40's or 50's, who are generally receptionists, keying in data whilst on the phone.


    I've had a mild case & switching to one of the specialist keyboards has helped. I use a Fingerworks [fingerworks.com] TouchStream ST - excellent but it takes some getting used to, is a right old pain if you work in the UK and need to use the £ sign (character map etc etc).

    The mouse thing is interesting - I have found that most problems occur in the hand that isn't using the mouse, as it's being lifted of the keyboard whilst mousing.
  • by Anonymous Coward on Thursday June 12, 2003 @09:42AM (#6181149)
    CTS is a type of RSI, they claim typing (a highly repetitive action) does not necessarily cause CTS. That's pretty much saying repetition is not associated with RSI.
    No it isn't. It's saying repetition of a very particular type is not associated with CTS.

    According to your logic, if I said that smoking wasn't associated with rabies (a type of disease), I'd be saying that smoking wasn't associated with any diseases at all. But It's perfectly possible to claim smoking isn't associated with rabies but is associated with a wide variety of other diseases.

    Please use logic more carefully.
  • Re:Not Ineveitable (Score:3, Informative)

    by Surak (18578) * <`moc.skcolbliam' `ta' `karus'> on Thursday June 12, 2003 @09:42AM (#6181152) Homepage Journal
    There's actually a lot of factors that contribute to carpal tunnel. I'm the same as you, I have no problems and have never used special keyboards or R/L hand mouse switching. A programmer friend of mine has to wear the wrist braces because his CTS is so bad, and he also started when he was young.

    Some things include factors such as your own work habits. For instance, do you take breaks from the keyboard and mouse? I take a break every couple of hours to stretch my legs, otherwise I start to get that cramps in my legs from sitting for too long. This is *good* for the wrists and highly encouraged by doctors to avoid RSIs such as CTS. Also the *size* of ones wrists could be a factor -- people with larger wrists have larger nerve pathways, and hence (possibly) a decreased risk for nerves getting pinched. I have large wrists -- so large in fact that many bracelets will not fit me.

  • by Anonymous Coward on Thursday June 12, 2003 @09:45AM (#6181169)
    Just remember to alternate... reduces the stress..
  • by Anonymous Coward on Thursday June 12, 2003 @09:50AM (#6181205)
    There is a big difference between CTS and RSI. Unfortunately, most people do not get that. CTS is relatively rare, extremely painful, and is very difficult to get rid of once you have it. CTS can sometimes be fixed by wrist surgery. The basic deal with CTS is that your carpal tunnel is too small for the goods running through it once they swell. You are in deep shyte if you get diagnosed with CTS


    RSI is basically tendinitis. There are a million causes for it and it is hard to track down. If you get it, you have to spend a good deal of time tracking down exactly where the cause is.


    Both are awful to have. But you can't appreciate the pain until you get it. It is disabling...try to get through your day without hands. Driving, eating, washing...all the basic necessities hurt like hell.


    Computer use is certainly a good aggravator, but you can get it from a variety of ways. It is very much a black science when you go to the doctor. Some people have the most awful ergonomics but suffer nothing, while people with perfect ergonomics get it.

  • Re:Not Ineveitable (Score:5, Informative)

    by Anonymous Coward on Thursday June 12, 2003 @09:50AM (#6181206)
    Actually, the more likely cause is the fact that most people lean on their elbows. This cause inflamation of the ulner nerve, which results in tingling in the fingers, usually starting with the pinky fingers. This can be solved quite easily by wearing elbow pads for a period of a week to 3 weeks, and taking a Super B Complex vitamin daily.

    Same symptoms as Carpal Tunnel, different reason.
  • by takev (214836) on Thursday June 12, 2003 @09:50AM (#6181214)
    I use a computer about 80 hours a week, which
    is a lot I know. And a few months ago I got a pain in my left wrist, so I stopped and actualy took some sick leave.

    But even after a week it still was painfull to type, so I tried to find out why and I located the problem to using the ctrl key, which made my hand strain (especialy the ctrl-b and ctrl-f combinations).

    The solution was rather simple, I remamped my ctrl key to the caps-lock key (old keyboards actualy had the ctrl key there). And I disabled the old ctrl key so that I would unlearn to use it.

    The next day and ever since I'm typing happely again. Except, I get confused when I have to type on some one elses workstation :-)

    BTW I already had the caps-lock disabled anyway, because I mostly use vi and it is rather anoying to see your lines joined instead of moving downwards, when you accidentaly have activated the caps-lock.
  • by corvi42 (235814) on Thursday June 12, 2003 @09:57AM (#6181256) Homepage Journal
    if its not a significant risk, then why did I get nearly debilitating pain in my wrists when I coded all day long with a standard keyboard, but it went away as soon as I switched to an M$ natural keyboard? I'd never had such pain before, and since I've switched, I haven't had it return. I'd say that this pain was "caused" by the use of a lousy keyboard for long periods - but maybe I'm deluding myself.
  • by docbrown42 (535974) on Thursday June 12, 2003 @10:25AM (#6181505) Homepage
    That damned little puck-mouse that came with the Mac G3s. I used one for almost 2 years, and because it didn't support my palm correctly, it screwed up my wrist. I know that shortly after they came out, you could buy a cover that gave wrist support, but my previous employer wouldn't buy one, so my wrist has problems.

    Of course, now I use trackballs almost exclusively, so it doesn't matter as much. Optical trackballs are SO nice!

  • Re:Do you exercise? (Score:2, Informative)

    by Troed (102527) on Thursday June 12, 2003 @10:26AM (#6181516) Homepage Journal
    Yeah, I'm fit, and I do/have done both sports, athletics and weight lifting. I don't touch McDonalds nor Coca Cola ..
  • by Anonymous Coward on Thursday June 12, 2003 @10:27AM (#6181518)
    I had the worst RSI in both arms, shoulders and back pains as well. It all started at once after years of 14h a day on the computer. I tried acupuncture, physiotherapy, geek gloves of many types and more.

    Using my new touchpad (synaptics is better for linux, mine isn't) and the smart-gloves from imakproducts.com (after reading about them in /.) I felt a relief, yet the situation was quite static, no serious improvement. What really helped was sports. Try swimming 2-3 times a week, this lets you put more pressure on the muscles then on the tendons and the spine. Having too much tension on the spine can reflect pain in various places in the body, even a pain that is similar to tendon inflammation.

    So... here's the prescription
    * Sit straight
    * Less hours
    * Touchpad
    * Smart Gloves
    * Ergonomic keyboard
    * Sports
    * Increase room temp.
    * Go for a break often, never continue working with pain
    * Sue your insurance
    * Eat stuff that is good for the liver (less alcohol then). Liver is the source of energy for the tendons.
    *
  • by Qzukk (229616) on Thursday June 12, 2003 @10:33AM (#6181569) Journal
    Its not computer use specifically thats the problem, its improper posture and position. This has been known since shortly after the problem was recognized.

    I've used computers since I got my commodore 64 a little more than 15 years ago. Never had a problem, until this year.

    This year, I sliced open one of my fingers bad. The bandage I was wearing changed my typing position, and within the 12 or so days I had the bandages on, my wrists started hurting and my fingers tingled. The bandage and wrist pain is gone now, but my fingers still do tingle on occasion.
  • by barryfandango (627554) on Thursday June 12, 2003 @10:35AM (#6181585)
    My girlfriend is a registered massage therapist and often fixes me. I can tell you that as a user who is mousing/typing eight hours a day, my forearms (especially the mousing right arm) are not healthy. Instead of the supple, flexible muscle that is supposed to be there, when my gf works on it it's like just under the skin there are lumps of chewing gum with crunchy pieces in them.

    Thanks to her help i'm getting better, however, and can offer this advice:

    - find the working position that is optimal for muscle relaxation. I have two desks put together in an "L" shape with an armless chair, so i can rest my elbows up at the level of the keyboard. What kills your muscles is having them flexed (even gently) for a long period of time.

    - stretch every 30-60 minutes. I do these three forearm stretches and find them very effective:

    1. Hold your arm straight out. Bend your hand forward at the wrist, pulling it with your other hand until you feel a gentle stretch. Hold it for at least 30 seconds (it takes at least this long for muscle fibers to get the hint and release.

    2. do the same thing bending your hand backwards.

    3. this one is more complicated but is really the money stretch: hold your arm straight out in front of you, make a fist with your hand and hold it tight. Rotate your arm to that the thumb-side of your fist is facing outward. Now grab the fist with your other hand and pull it down and outwards, simultaneously bending the wrist and rotating the arm further. If done properly you should feel a nice stretch all through your forearm. Be gentle: it's more important to hold it longer than to push it harder.

    If you're a Canadian living in Ontario or BC, you can go see a Registered Massage Therapist - they do wonders, and can give you advice on stretching and posture. Also Active Release Therapy (or ART,) which is provided by certain RMT's and Chiropractors, is pure gold for more serious problems. I don't know what regulatory bodies exist in the states, but i know that in Canada's unregulated provinces (everywhere but BC and Ontario) a lot of massage workers are either foofie-lala new age aromatherapy types or borderline sex industry workers, as opposed to genuine health care providers - so be careful.
  • by dwvanstone (581420) on Thursday June 12, 2003 @10:35AM (#6181589)
    I've lived through an unfortunate bout of tendonitis. I was still experiencing tingling symptoms and arm pains and popping my anti-inflammatories after 8 months when I finally found a physical therapist who successfully pinpointed that I have very tight muscles in my neck (scalenes) and chest (pec minor) that are impinging on my circulation & nerves in my arms. When he works those muscles, I get referred tingles & pain in my arms.

    Through some Alexander technique [alexandertechnique.com] and structural integration [rolfguild.org] work (i.e., rolfing), I'm finally better.

    Whereas my regular doctor blamed computer usage and recommended I take off a few months from work, my PT believes this my symptoms were caused by poor posture over a lifetime - shoulders drooping forward, neck dropping forward. I believe the PT more than my doctor. (I have since changed doctors.)

  • by Anonymous Coward on Thursday June 12, 2003 @11:18AM (#6182066)
    Carpal Tunnel Syndrome, the slowing of the median nerve in the carpal tunnel due to pressure on the nerve, is not a Repetitive Strain Injury. For clarity of discussion, these are the symptoms of CTS (as opposed to a tendonitis or other soft-tissue irritation):
    * Numbness or pain in your hand, forearm, or wrist that awakens you at night.
    * Occasional tingling, numbness, "pins-and-needles" sensation, or pain. The feeling is similar to your hand falling asleep.
    * Numbness or pain that worsens while using your hand or wrist, especially when gripping an object with your hand or bending (flexing) your wrist.
    * Occasional aching pain in your forearm between your elbow and wrist.

    Here are a couple medical journal articles from several years ago, non-Danish in origin, that detail some of the risk factors of CTS:
    http://www.ncbi.nlm.nih.gov:80/entrez/query. fcgi?c md=Retrieve&db=PubMed&list_uids=8198771&dopt=Abstr act
    http://www.ncbi.nlm.nih.gov:80/entrez/query.f cgi?c md=Retrieve&db=PubMed&list_uids=9048313&dopt=Abstr act

    Briefly, in case you're not on a network with access to the full text of those articles, analysis of over 5000 patients showed no correlation between type of employment and CTS. Risk factors included thyroid disease, obesity, and a "square" shape to the wrist. Simply put, conditions that contribute to elevated levels of intra-articular fluid, and skeletal structure that elevates the pressures of those fluids on the median nerve, will contribute to the occurrence of CTS.
  • by useruser (638080) on Thursday June 12, 2003 @12:13PM (#6182676) Homepage Journal

    5% risk, huh? Wow, that sure is small! Oh wait, they don't cite the baseline incidence, so who knows if its all that small. 5% could be a 300% greater risk for all we know.

    No signifiant relationship between more than 20 hours of use of a keyboard? Great news, for me: I work 60 hours a week with a keyboard! Oh wait, they neglected to analyze the subset of individuals like me. Talk about a low powered measure and analysis. Did they even look at the distribution? I bet there's a slight skew.

    Well I'm glad the numbness in my palm isn't caused by my excessive computer use. Then what the hell is causing it? I sit on my butt all day and sleep on my back all night! What else could it be?

    Seriously, until every scientist on Earth is forced to pass a course on psychometrics, this kind of research gets us nowhere. Statistics is a garbage in, garbage out practice.

  • Re:Not Ineveitable (Score:2, Informative)

    by ZESTA (18433) on Thursday June 12, 2003 @12:17PM (#6182732) Homepage
    If your pinky is numb, it is from something other than CTS. I recently had CTS surgery in my right hand, and will soon for my left. CTS does not effect the pinky or the pinky side of your ring finger, as those areas are served by a nerve that is outside of the carpal tunnel.

    -Randy
  • by maw (25860) on Thursday June 12, 2003 @12:21PM (#6182772) Journal
    Ah, kindred typist :) I've never had any problems due to typing either. However, be careful about excessive mousing - I did have pains in my right hand from excessive mousing. Taking off a long weekend away from computers helped, as did buying a mousepad with a wrist support.
  • Dude, you are wrong (Score:2, Informative)

    by Timwit (597019) on Thursday June 12, 2003 @12:50PM (#6183054) Journal
    You conclude that because your breaks give you time to recover, avoiding RSI should be a matter of common sense for everyone--not so fast pal. Sometimes conditions can change and what was once adequate rest is no longer adequate. When conditions change quickly you have no previous experience to draw upon, and you can do damage even while behaving prudently.

    My RSI (a tendinitis, not carpal tunnel) hit me out of the blue when I was 26, and I've never been the same since. Perhaps an infection rendered my tendon sheaths fragile for a few days, or for some reason my collagen production decreased temporarily. But whatever the cause, I was past the point of no return in no time flat. The change was so abrupt that it may not have been possible to avoid at all.
  • by figa (25712) on Thursday June 12, 2003 @12:55PM (#6183121) Journal
    My family doctor told me to get a "gripper" when my RSI first set in, and that's what finally put me over the edge. I'm now seeing a occupational medicine specialist, and she literally laughed at the "gripper" when I told her about it. RSI is not caused by lack of strength, it's caused by overuse. Adding 50 more reps to your hands is going to make things worse.

    The best thing you can do to prevent RSI is take breaks on the computer and do aerobic exercise. Swimming, walking and elliptical stationary machines are the best, from my experience.

    As for the original post, it's inhuman what the US does to meat processing workers. Unfortunately, being white doesn't make my now purple hands feel any better. Everyone needs access to affordable healthcare, physical therapy, and preventative medicine. The current administration's gutting OSHA and undermining its ergonomics recommendations was a terrible blow to everyone.

  • Re:Not Ineveitable (Score:2, Informative)

    by Kooglebot (597765) on Thursday June 12, 2003 @01:33PM (#6183535)
    Wrong. Not the same symptoms, because it is not the pinky and ring finger that are most affected by CTS. There are many forms of RSI, and it's just as silly to say that are most likely to be Cubital Tunnel Syndrome (i.e. a pinched ulnar nerve at the elbow) as it is to say that they are all Carpal TS.

    You are right in pointing out that leaning on the elbow will inflame the ulnar nerve, but I don't lean on my elbows when I type (and I'm careful not to at any other time) and I'm really hurting from this. Just having the elbows bent aggravates the problem. I lowered my keyboard (to lower the angle of my arms when typing) and that has helped, but frankly, I am on the verge of quitting my job because of it. When I type, it hurts, and when I stop, it goes away.
  • Re:Not Ineveitable (Score:2, Informative)

    by Troed (102527) on Thursday June 12, 2003 @04:10PM (#6184949) Homepage Journal
    The study considers 7 hours a day to be a lot - and concentrates on keyboard use. My work day is longer than 7 hours - and then I do spend time at home also in front of a computer. Also, a keyboard is _nothing_ compared to a mouse when it comes to causing CTS.
  • Re:DVORAK is crap? (Score:1, Informative)

    by Anonymous Coward on Thursday June 12, 2003 @05:24PM (#6185720)
    Have you guys seen this applet (http://www.acm.vt.edu/%7Ejmaxwell/dvorak/compare. html) which compares QWERTY vs Dvorak given a sample of text?

    For example, I copy-pasted thatguywhoiam's post into the applet. It reported that having been typed using QWERTY, thatguywhoiam's fingers moved about 24.4 meters while composing his post. On the other hand, had he used Dvorak instead his fingers would have travelled significantly less, about 14.3 meters.

    The applet also gives some other interesting stats, such as the usage of home row letters under the two keyboards (63% Dvorak versus only 31% QWERTY for thatguywhoiam's post).

    Finally, the applet's author even includes a link to the source code if you're so inclined.

    Cool, eh?

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