Ergonomics Input Devices

Computers Controlled by Gesture

In an interesting video clip from the BBC’s ‘Click’ programme called ‘Computers Controlled by Gesture’, there is a summary of current developments in the world of human gesture control as an input device. It brings back memories of Tom Cruise in “Minority Report“.

Whether this form of computer input technology will ever see serious light of day or not, or whether it will replace the keyboard and mouse, is anyone’s guess, but it is interesting to see trends in technology moving away from using the standard devices (although it is hinted that currently there is no good replacement for a keyboard for text entry).

Whether this technology can save us from RSI related injuries is open to debate; it may well transpire that they just mean we are susceptible to different types of injuries, but it is a good sign that developers are at least rethinking the now traditional methods of interacting with computers. It could lead to opportunities in computer use for people with all kinds of different disabilities, and not just RSI.

Is this the start of a new age in ergonomics, or is it just the latest phase of hi-tech gimmickry ?

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Ergonomics RSI Tips

Forearm extensor muscles, wrist position and RSI

When you position your hands at a keyboard as discussed in an earlier article referring to ‘typing with clawed hands’, bad positioning of the wrist can lead to overuse injuries caused by strain in your forearm extensor muscles.

clawed_hands_rsi_sm.jpgThe common position for hands hovering above a keyboard is as shown on the right, which I refer to as the ‘claw’. This position elevates the tension in the aforementioned extensor muscles, causing them to become fatigued over prolonged periods of time. Typing whilst the hand/wrists are in this position (another common posture mistake) will further

Career Ergonomics RSI Tips

RSI – What to do? (Part 3 – RSI Dealing With A Long Term Condition)

The following article is a follow-on from RSI – What to do? (Part 1 – RSI Initial Symptoms) and RSI – What to do? (Part 2 – RSI Dealing With Progressive Symptoms) .

OK, so you are experiencing a long term RSI condition, ie it has gradually worsened for more than 2 years. You are in continual pain at work and find it difficult to do your job. You have perhaps gone through consultations with ergonomists, doctors, physiotherapists and just about anybody who’ll listen, but still you find no relief. You struggle to remember what it felt like not to associate pain with computer use. You may be wearing an arm brace (and probably have a large collection of them by now), and you probably have a sizeable collection of strange ergonomic mice at your computer that don’t seem to help. Your employer keeps expecting the same work output from you and you stress about how you can get through it. You get by by doing what you can, but generally come home each night from work and feel anxious about the situation and the searing pain down your arms. You wonder what you can do, and how you are supposed to live a normal life – you can’t remember what normal life was like before this injury!

So what are the options then? Well I remember a great bit of advice from my father

Miscellaneous RSI Tips

Forearm Extensor Muscle Overuse and RSI

(Article updated 22 April 2011)

RSI symptoms are very often the result of extremely tight (overused) forearm extensor muscles. These muscles are located in the upper forearm region. They are used to raise the wrist and fingers, which is the primary motion involved in unergonomic keyboard and mouse driven activities such as having the hands bend backwards and fingers raised while hovering over a keyboard ready to type.

The tight and potentially knotted extensor muscles end up being over used, and don’t get the chance to recover. This leaves them in a permanently fatigued state, tightly tensioning the forearm tendons to which the extensor muscles are attached, causing referred pain down the tight tendons into the hands, wrist and fingers.

Forearm Extensor Muscles
Forearm Extensor Muscles

The forearm extensor muscles consist of five main muscles and are shown colour coded in their approximate position in the image above. The image is meant for indication only, and I recommend you search for a more detailed anatomical diagram for a more accurate placement.

The five forearm extensor muscles are –

  1. Extensor carpus radialis longus which attaches to the index finger but controls bending of the wrist towards the thumb as well as bending the wrist back.
  2. Extensor carpi radialis brevis which attaches to the middle finger and again controls the raising of the wrist.
  3. Extensor digitorum which attaches to all four fingers of the hand but controls the straightening of the 3rd, 4th, 5th fingers.
  4. Extensor carpi ulnarus which attaches to the 5th finger and is used to cock the wrist outwards, for example reaching for a far away key on a keyboard.
  5. Extensor indicis attaches from not far behind the wrist to the index finger and is the primary control muscle of that finger.

The extensor muscles exist at different depths in the arm and some are hard to precisely locate.

Over use strains along any of these extensor muscles from bad ergonomic practices (like having a clawed wrist at a keyboard) can lead to them developing knots (solid tissue that is scarred). This scarring results in pain (to press on at the location of the knots) but is mainly noticeable as referred pain down the forearms into the back of the hands and fingers – which is a classic RSI symptom. The extensor muscles (apart from the extensor indicis)  attach to various bones around the elbow joint, and some pain symptoms can also be found close in to the attachment points.

You can do a check to see how fatigued your forearm extensor muscles are. Using your left hand to check your right forearm extensor muscles press down firmly with the thumb onto the full area of the various forearm extensor muscles, move the position of the thumb over these muscles and check for pain. Repeat the diagnosis with the left arm extensor muscles and your right thumb.


If you are in any doubt about what these muscles do, press your thumb on your arm as above and raise your wrist up as if you were about to type. Also raise and wiggle your fingers. With your thumb, you should be able to feel the various extensor muscles tightening as your wrist and fingers raise.

If you find the extensor muscles to be in pain with the above procedure then these muscles are fatigued. It also means that ergonomically, you are not using your keyboard properly and are probably typing using the claw, which causes this type of problem. This type of condition is one of the most common mechanisms for RSI pain, but can easily be addressed by changing the way you type.

If you are experiencing pain in these muscles, it is time to try to relieve them which can be done by massage, icing and rest. Consult your doctor or a trained physiotherapist to find out the best techniques which may include ultrasound. You should also read my post about Trigger Point  Therapy on extensor forearm muscles which describes my findings from an excellent book for self help in RSI diagnosis and massage techniques. You may also want to try to find a knowledgeable Trigger Point massage therapist.

It is also time to re-assess your typing technique otherwise you may be placing yourself at risk of an RSI type condition. This may send the forearm extensor muscles into a more permanently fatigued state, from which recovery may be difficult, and in some extreme cases may be impossible.

In my own case, forearm muscle fatigue is the primary mechanism for my RSI pain. Unfortunately for me, I learned of the prevention techniques several years after my symptoms began, when these symptoms had already become more persistent.  I do however still get some much needed temporary pain relief these days from massage of the forearm extensor muscles and tendons, just not very long  lasting , but my injury is after all a long term one.

Related articles on forearm extensor muscles :

Typing with clawed hands

Forearm extensor muscle overuse wrist position and RSI

Does forearm extensor trigger point massage offerer a potential cure for RSI?

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Does forearm extensor trigger point massage offerer a potential cure for RSIDoes forearm extensor trigger point massage offerer a potential cure for RSI??
Ergonomics RSI Tips

RSI – What to do? (Part 2 – RSI Dealing With Progressive Symptoms)

This is a follow on article from Part 1 which dealt with managing Initial RSI Symptoms.

The following is relevant if you have been experiencing RSI symptoms for a few months and they are now persistent in nature.

wrist_pain.jpgThe rate of success in dealing with RSI symptoms is proportional to the speed that a sufferer can diagnose the causes of those symptoms, and their understanding of the corrective actions required to avoid further injury.

The onset time for RSI injuries can be fairly rapid (in my own case I went from having initial symptoms to intermediate symptoms within 3 to 4 months. It is therefore vital that sufferers glean RSI knowledge as fast as possible, try to understand the causes of their symptoms, and make the necessary adjustments to their working practices.

So the scenario for this article is of a worker who has had RSI symptoms for a few months, and is experiencing any of the following –

Ergonomics Miscellaneous RSI

RSI – will workers ever listen?

RSI is in the news again today with the Chartered Society of Physiotherapy calling for employers to take RSI injuries more seriously. Among their recommendations are – regular breaks for workers, access to Occupational Health Specialists, and risk assessments for employees. All of these suggestions are great, and need to be seriously looked at since there appears to be a spiraling in the numbers of cases of RSI injuries. In the same article, according to the Health and Safety Executive, there were 115,00 new cases of RSI reported in the UK alone last year.

Coming from an office environment with a large employer, I have witnessed first hand how difficult it is to educate a workforce in the dangers of using a computer. Employers can spend vast sums of money on employee ergonomic education and can still make little impact on workers’ perceptions on computer use.

Ergonomics RSI Tips

RSI – What to do? (Part 1 – RSI Initial Symptoms)

It can be a very confusing time for a computer user when they first experience RSI symptoms. The symptoms can often develop after a protracted period of intensified work, which may be ongoing. Initial injury symptoms can be very mild and will more than likely be ignored by the worker who will continue to work through them. This may be because the worker feels that the symptoms are very slight, and are manageable, or they may simply be confused about what those symptoms are. At this stage it is highly likely that the worker will not consult anyone about their symptoms eg an ergonomist, a company doctor, GP etc, and will more often than not want to avoid exposing their problem (however small) to their employer.

The danger with this is that, if symptoms are left unchecked, it can lead to their rapid worsening and the long march to a more debilitating (and difficult to treat) condition.

This need not be the case. There is a lot you can do at this early stage of RSI symptoms to help yourself.

Ergonomics Input Devices Miscellaneous RSI Tips

How ‘Clicked Off’ Are You About Your Mouse? – mouse clicking alternatives and RSI

The act of a human clicking a mouse to control a computer has been around since the inception of window based GUI (Graphical User Interface) systems. Before GUI based systems were around, keyboards were the prominent way of user interaction with a computer. Mouse based systems were a leap forward in terms of computer usability, and have allowed a multitude of different graphical applications to be built around them.

The biggest problem with the invention of the mouse, and for that matter all current GUI based computer systems, is that they force a user to do a very repetitive motion that had up until their invention not been done before, ie the repetitive small movement of the index fingers to send a ‘click’ to the computer to say ‘do this’. Sometimes this repetitive task can be very intensive (depending on the application being used). This has over the last 15 years or so led to a large increase in cases of Repetitive Strain Injuries (RSI).

So what alternatives to standard mouse ‘clicking’ exist right now for the computer user? (Note: the following is by no means an exhaustive list)

  • keyboard short cuts
  • voice recognition software
  • foot pedal clicking
  • graphics tablet/tablet PC pen “taps”
  • software generated clicks
  • touch screen monitors

Each of the above have their own set of positive as well as negative points. The following is a brief summary

Ergonomics Input Devices RSI Tips

Of Mice and Men – Mice and RSI

I’ve had a rather unpleasant history with mouse use, culminating in the inability to use a bog standard mouse with either hand for more than 2-3 minutes before the onset of severe pain. This reaction has built up over many years of mouse (ab)usage, and I have a certain loathing for the devices now. It has to be said that many of the cheaper mice (normally the ones shipped by certain PC manufacturers) are some of the most unergonomic pieces of equipment available. Computer manufacturers have a lot to answer for having shipped us less than ergonomic mice with their computers for the last 20 years. Quite often an end user does not experience any other type of mouse apart from the one that ships with their computer system. Whilst these mice are designed with aesthetically pleasing features, their ergonomic qualities leave a lot to be desired. This can of course be tolerable if the user seldom uses the computer, but if they do use it a lot then it can ultimately lead to the onset of RSI type symptoms.

Having seen what manufacturers ship with their systems, I would be a proponent of legislation to ensure that the basic minimum mouse is an ergonomic one.

Ergonomics RSI Tips

Keyboard Thumping and RSI

One vivid memory of my injury when employed was watching how fellow workers in certain situations thumped their keyboards. I remember it well, because I used to wince when I saw them do it.

Having been an RSI sufferer for the best part of a decade, and having come from an identical background to my colleagues (and no doubt had been prone to thumping keyboards in my time), I fully realised the implications of the use of excessive force as people interacted with their keyboards.

Keyboard thumping (the act of hitting the keyboard keys with exaggerated force or heavy pounding) can be barely noticed by the user, but is usually attributable to them being overly frustrated with the computer/piece of software being used or or emotionally involved with an angry ‘flame’ mail etc. During these times it is not unusual for this anger and stress to build up and be vented in this way. There is really no place for emotional frustration and computer use. Your body needs to be ergonomically positioned, relaxed and fluid when interacting with computers in order to minimise the exposure to RSI causing effects, and not demonstrating emotional reactions like the guy below!

The keyboard/computer is ‘paying the price’ for the person’s anger and frustration.