More about RSI

What is RSI?

The term Repetitive Strain Injury (RSI) is not, in itself, a medical diagnosis. It is used to describe a number of named musculoskeletal conditions (such as Tenosynovitis, Cramp of the Hand, Tendinitis, etc.) as well as 'diffuse RSI' which is more difficult to define but which recent research attributes to nerve damage. These are almost always occupational in origin. 'Repetitive Strain Injury' is a term similar to that of 'sports injury' in that it tells more about how the injury was sustained, rather than what the injury actually is.

RSI conditions occur in both upper and lower limbs as well affecting the spine in various areas, which in turn can cause referred pain into the limbs, making diagnosis difficult. Symptoms of numbness, tingling, sharp pain, dull ache, weakness, loss of grip and restricted movement of limbs can render people incapable of carrying out the simplest of tasks, at home or at work. Lack of accurate diagnosis and access to appropriate treatment further exacerbates the condition, frequently resulting in job loss and economic deprivation.

What are the different forms of RSI ?

RSI can be broken down into three main groups, those being disorders of the tendons, nerves and muscles. Below are listed some of the more common ailments including a brief explanation for each.

Group 1 Tendons

Tendinitis
This condition refers to the tender swelling of tendons, the rope or cord like structures which connect muscles to bones in order to work the joints of the body. When any group of tendons are overused microscopic tears can result, leading to inflammation. Even a minor contraction in the muscle can then lead to further irritation.

Tenosynovitis
Tenosynovitis involves inflammation of the protective sheaths surrounding some tendons. It most commonly affects the tendons of the hand, wrist and arms, although it may occur at other tendon sites. When the gliding surfaces of the tendon and sheath become roughened and inflamed from overuse, tenosynovitis will present as aching, tenderness and swelling of the affected area.

Epicondylitis
Epicondylitis is a common and well defined condition affecting the elbow. It is characterised by pain at the epicondyle, the bony parts on the inside and outside of the elbow joint. It appears under many names and is commonly known as Tennis Elbow. Epicondylitis is the result of some kind of muscle lesion or inflammation of tendons at the point where they attach to the bone.

Trigger finger
Trigger Finger or Thumb involves the flexor tendons of the hand, which control bending movements of the fingers. When the finger or thumb is stretched out, it will seem to lock in position and be unable to move on its own, though it can be easily moved with the other hand or by another person. There may be a nodule, which may be slightly tender, at the base of the affected finger or thumb. Treatment may include anti-inflammatories, splinting, steroid injections into the affected area, or surgery.

De Quervain’s disease
De Quervain's Disease, also known as de Quervain's Stenosing Tenovaginitis, is a form of tenosynivitis. De Quervain's results from inflammation or constriction of the tendons of the muscles of the thumb at the point where they pass into the wrist. Pain may be felt at the base of the thumb near the wrist. Treatment may include steroid injections or surgery.

Dupuytrens Contracture
Dupuytren's Contracture is a hand disorder in which the fingers bend towards the palm and cannot be straightened. The little and ring fingers are most commonly affected but all the fingers can become involved. In patients with this condition, scar tissue accumulates under the skin on the palm of the hand. The tissue (fascia) thickens and shortens so that tendons connected to the fingers cannot move freely.

Reference – Repetitive strain injury Association {RSIA}>

Different forms of R.S.I. continued, or go to Top of Page

Group 2 - Nerves

Carpal Tunnel Syndrome
The carpal tunnel is a passageway in the wrist formed by the eight carpal (wrist) bones, which make up the floor and sides of the tunnel, and the transverse carpal ligament, a strong ligament stretching across the roof of the tunnel.
In carpal tunnel syndrome (CTS) the median nerve is squeezed, often because the tendons become swollen and overfill the tunnel. Symptoms, such as numbness, burning or tingling, affect the thumb, index finger, fore finger and inside of the fourth finger, as well as the same region of the hand. CTS is the most commonly diagnosed form of R.S.I.

Cubital Tunnel Syndrome
The cubital tunnel is a passageway inside the elbow (cubitus is Latin for elbow). The ulnar nerve is one of the major nerves of the arm. It controls forearm movement, finger movement and grip and provides sensation to the little finger and half of the ring finger. The ulnar nerve passes through the cubital tunnel as it crosses behind the elbow. The tunnel is lined with a sheath or fascia of tissue whose function is to protect the ulnar nerve as it slides through the bony tunnel. Cubital Tunnel Syndrome occurs when this nerve is compressed or injured

Guyon’s Canal Syndrome
Guyon's tunnel is a space in the wrist which contains the ulnar artery and vein as well as the ulnar nerve, which is one of the major nerves in the arm. Compression of the nerve at this point can lead to, among other symptoms, loss of sensation and loss of ability to stretch and flex the fourth and fifth fingers, and general weakness in the hand.
Treatment options can include avoiding activities which aggravate the condition, splinting, anti-inflammatory medication, steroid injections, and physiotherapy. If these are unsuccessful, surgery to decompress the nerve may be needed.

Pronator Teres Syndrome
The pronator teres is a muscle in the forearm which is used in the act of turning the hand so the palm faces downwards (pronation). In Pronator Teres Syndrome, the median nerve (long nerve running down the arm, through the wrist and into the hand) can become compressed by the pronator teres. This causes sensory symptoms such as numbness, tingling and pins and needles in the fingers and weakness in gripping and pinching movements. The pronator teres itself may be enlarged. It is important to note that this syndrome rarely shows up on electro-diagnostic conduction tests. Treatments include anti-inflammatories, TENS to assist pain reduction, splinting, and physiotherapy. As in all RSI type conditions, some changes will usually need to be made to the activity or process which is causing the pain. If other strategies are not helpful, surgery may be considered.

Radial Tunnel Syndrome
The radial tunnel is a space formed between five anatomical structures at the outside point of the elbow. Movements such as repetitive rotation of the forearm cause constriction of this space which puts pressure on the posterior interosseous nerve, a branch of the radial nerve.
Symptoms may include pain in the elbow and/or forearm, which may feel worse when the middle finger is pressed backwards.
Treatments may include restricting movements of the forearm, splinting, anti-inflammatories, and physiotherapy. As in all RSI-type conditions, some changes will usually need to be made to the activity or process which is causing the pain. If other strategies are not helpful, surgery may be considered.

Reference-Repetitive strain injury Association {RSIA}

Different forms of R.S.I. continued, or go to Top of Page

Group 3 – Muscles

Muscle sprain and strain
Muscle strain is excessive stretching or working of a muscle, resulting in pain and inflammation. Different tissues in the body have different tolerances to stretching. Ligaments, as above, are flexible but do not stretch well, leaving them prone to injury when overstretched. Muscles have a different response to stretching. The fibres within the muscles tear, which can cause muscle pain, but they regenerate, becoming larger and stronger. This happens to a greater or lesser extent depending on the activity - e.g. when bodybuilding the pain, recovery and muscle growth cycle is quicker and more noticeable, but this same process does go on with other repetitive activities we carry out in our jobs and daily lives. Hence the term 'keyboard athlete'. In RSI, repeated strain and the magnitude of the load exceed the muscle tissue's ability to repair. This may explain why workers often first report problems after a period of increased workload.

Myalgia
This means simply "muscle pain". Not everyone accepts that muscles can become injured through repetitive use, and those who do not, assert that pain in muscle is either fatigue from unaccustomed work (and will go away in time with rest), or is imagined. They cannot believe that muscles can be damaged from low level activity.
Those who do believe that low-level activity can cause myalgia argue that with low-level activity carried out for prolonged periods, only certain muscle fibres are used - the load is not shared or rotated throughout the whole muscle. Another factor may be that when the muscle is contracted, intramuscular pressure rises to such an extent that normal blood flow and oxygen exchange is restricted. This can lead to pain, inflammation and scar tissue. It's important to note that this muscle activity can be for the purpose of holding a static posture as well as for movement, so holding a fixed position for long periods of time can also be a factor in muscle pain.

Myositis
Myositis is an umbrella term for a number of muscle diseases in which inflammation and degenerative changes occur. Some doctors consider mysotis to be an autoimmune condition. It is not clear what causes myositis, but a number of factors may be involved including genetic pre-disposition plus exposure to chemicals, viruses or other infectious agents. Sometimes people with mysositis go on to develop Raynaud's Disease. Like Raynaud's, mysositis is not an RSI-type conditon but it does have some features in common and may be one of the conditions a rheumatologist or neurologist will be looking out for during the diagnostic process.

Writers Cramp
Writers Cramp has been known to the medical profession for many years. There are clear descriptions of the condition in nineteenth century medical books, when it was known as ‘Scriveners’s Palsy’. Writers Cramp It is part of a family of disorders known as Dystonia which are characterised by muscle spasms and sometimes abnormal postures or twisting movements of the affected part of the body. Although historically the condition has been associated with those who earn their living by writing, the term is also used to cover general muscle cramps affecting some musicians, painters, office workers etc.

Reference- Repetitive strain injury Association {RSIA}

What causes RSI ?

Repetitive Strain Injuries are unlikely to have one single cause. In most cases, a mix of factors will combine to result in an RSI-type condition. Some of these factors, the primary factors, are mainly to do with the (working) environment. However, there will usually also be some secondary factors, which may be personal to the individual.
Primary factors may include, ergonomically unsound workstation, prolonged periods of work without adequate breaks, sustained overuse from too much repetitive movement, poor posture, excessive workload, patterns of work and a cold working environment.
Secondary causes of RSI may include (but are not limited to):

• Predisposition. Factors such as age, intrinsic strength, and general health, may all contribute to differing levels of tolerance to repetitive or prolonged strain in individuals.
• Stress. Stress makes muscles and soft tissues tense up, and when they tense up, they are more likely to be injured. Both physical and social stressors at work may contribute to this process.

RSI is by no means confined to keyboard workers but there can be no doubt that the increased prevalence of these painful and sometimes disabling conditions is related to the huge rise in computer use since the late 1980s.

The Health and Safety Executive (HSE) has published guidelines to employers on how to comply with the display screen equipment regulations. Insufficient rest breaks are a key risk factor and computer users may also face repetitive keyboard work, awkward gripping and twisting movements associated with mouse use and poor overall posture. In particular hot-desking, sharing work-stations, and the widespread use of laptops do not always take account of employee needs and the varying heights and sizes of individual computer users.

There are many actions associated with computer use which, if left uncorrected, may lead to RSI-type conditions in some individuals. Some of these actions can be avoided by better workstation or equipment design. However many computer users will also need to make the effort to change their computing style
Many computer users have a tendency to type with their wrists resting on the desk in front of the keyboard. This can compress the space available for the median nerve to the hand, leading to carpal tunnel syndrome. Using a soft wrist rest may help, but they have their disadvantages as they may actually discourage computer users from adopting a better typing style. It is generally best to type with the hands hovering above the keyboard, parallel with the arms (i.e. with wrists straight).

There are also risks associated with using the mouse. Many people use the mouse in the same way as the keyboard, with the wrist leaning against the desk and all the movement pivoting from the wrist. In addition, the design of the standard mouse that comes with most computers involves awkward gripping movements. The design of most keyboards means that the mouse has to be placed too far to the side, meaning the arm has to maintain a stretched posture. A better way of using the mouse is to hold the mouse lightly and make smooth movements involving the whole arm. Regular breaks from activity and releasing the pressure in the hands, wrists and forearms seems beneficial. Breaks will often be required to be kept to a minimum due to work pressures, but recent studies have shown just by taking a thirty second break every five minutes, plus a five minute break every half hour or so will greatly decrease your chances of developing R.S.I.

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Mouse and Keyboard use in relation to RSI

Once described in the Western Journal of Medicine as a “manifestation of an occupational epidemic” the mouse has become essential to the everyday use of computers. Although being increasingly used the device itself hasn’t fundamentally changed in design since it’s invention in 1968 by Douglas Engelbart. Today there are dozens of variations of the mouse such as, inverted mice also known as trackballs, hand held pointers, and countless ergonomically designed devices claiming to reduce or stop RSI. Some of these devices may in fact actually work as they claim but CTS and what is now being called MAS Mouse Arm Syndrome are still a workplace plague spreading to where-ever computers and mice are found.

MAS - Mouse Arm Syndrome is a form of RSI - Repetitive Strain Injury has been studied extensively in a number of countries. Today it is well known that prolonged use of a computer mouse can cause pain, stiffness and often even permanent damage to the muscles and tendons of the human body. Those who sit for long duration behind the computer without breaks may, over a period of time, develop RSI (Repetitive Strain Injury). This can lead to Mouse Arm, which relates directly to the prolonged use of the mouse.

Mouse vs. Keyboard

It is very likely that prolonged repetitive use of both the keyboard and the mouse can contribute to the onset of RSI. Some recent studies have found an increased risk associated with the mouse as opposed to the keyboard.

One recent study in particular conducted in Denmark which involved nearly 10,000 people suggested that using a mouse device for more than 20 hours per week was associated with a risk of developing C.T.S. and in comparison found no significant risk associated with the keyboard. It has been estimated that one individual who uses a mouse on daily basis can turn out over 2,000,000 mouse clicks a year and travel over 100 km on there mouse pad and a proportion of this distance is attributed to just fidgeting about and moving unnecessarily over the mouse pad. These movements do not take into account the amount of time the hand is just holding onto or hovering over the mouse, during which time the muscles and tendons in the hand and wrist are tensed and stretched. A recent survey fielded for one of the largest mouse manufacturer’s in the world questioned 1000 internet users and found that 63% of respondents spent more time holding their mouse than any other commonly held objects including cell phones, remote controls steering wheels or even their lovers. The same manufacturer is currently turning out 270,000 units each day or 6,000,000 per month. Given these figures it seems likely the term “Mouse Arm Syndrome” will be heard more often in the future.

Physical effects on muscle and tendon groups of mouse use

Below are some of the major problems when using a mouse with relation to which muscles and tendons that are mostly affected by repetitive and / or prolonged mouse usage.

Starting with the hand. When the hand is completely relaxed the fingers flex and the hand is half way between a fist and completely straight. This balances the tension between the flexors and extensors of the fingers. When the flexors are tight they can trap the median nerve and cause what is commonly but called "carpal tunnel syndrome." When the extensors are too tight they can cause epicondylitis or "tennis elbow." They can even trap the radial nerve and cause numbness in the hand. In order to prevent this the hand must be positioned so that it is not too straight and not closed too tight ie- relaxed .A regular mouse causes the extensors to tighten in order to hold the fingers slightly above the mouse buttons. They are under slight tension all the time which causes the cumulative injury effect.

Next the wrist. With a regular mouse the wrist is usually extended slightly. This is not a major problem but the tension on the wrist extensors to maintain this position is definitely a problem. When using a mouse the weight of the arm and shoulder is supported by the trapezius and levator scapulae muscles. The scalenes also tighten as the shoulder is supported. This is because you cannot rest the weight of the arm and shoulder on the mouse while using it. Almost everyone has felt that "burning" in the muscles between the neck and shoulder after using a mouse for any length of time. This causes damage to the tissues that builds up over time. These symptoms can be painful in the least and debilitating for an individual in extreme cases, which are becoming more common.

References – repetitive strain injury association {RSIA}
- journal of ergonomics

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Incidence, occurrence of RSI

How many people are affected by RSI ?

The precise number of people affected by RSI is difficult to determine, however some statistics and estimates are available which have been listed below

Europe
during the period between 1998-1999 an estimated 4.1 million people suffered from the disorder. (European Union Labour Force)

United states
for the same period between 1.8-2.1 million people affected.(Bureau of Labour Statistics)

Statistics for the rest of the world are difficult to come by however the RSI Association estimates it will in some way affect 8 out of 10 workers in some time of their life and globally now one out of every fifty workers will have been forced to take time off due to the affliction. Estimates could be as high as 100 million people worldwide that have some form of RSI.

Is it a growing problem?

Statistics have shown that from the time of the first PC’s in the early eighties, RSI has steadily increased to account for 60% of all work related illnesses. In 1981 RSI accounted for 18% of all illnesses and had steadily risen to 60% by 1998. The problem has remained stable as a percentage but has increased due to the increased prevalence of computers and job specialisation.(Occupational Safety and Health Administration)

Is it a growing problem?

One of the biggest problems with RSI is that it is difficult to diagnose unless it is an extreme case. For this reason many suffer in silence until the problem has gone too far and becomes very painful or even debilitating. There is also the stigma that is often attached to those who claim to have RSI, which only serves to magnify the problem.
A person who has RSI will often have aches and pains, headaches and increased stress due their inability to work as efficiently as before. More errors are likely and productivity will almost certainly be affected. These a few early symptoms of a typical RSI. case. Once the condition advances an individual will often need to take pain killers just to function in there job. The next step is usually extreme pain lack of coordination and dexterity, inability to perform day to day tasks effectively which will almost certainly result in time off work. In some cases surgery may be required to correct the condition or alleviate pain.

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Costs of RSI in Europe, US, Worldwide

It is difficult to give an accurate figure on the economic costs of RSI world wide how ever some figures are available.

• In the United kingdom between 8 and 30 billion USD per year. (Trade Union Council)
• In the United States direct costs of over 20 billion USD and indirect cost between 30 and 40 billion USD. (Occupational Safety and Health Administration)
• In the European union between 40 and 60 billion USD are spent on RSI (European Union Labour Force)

On a global scale the most conservative estimate of the related costs of RSI disorders run into the hundreds of billions of dollars. These costs include absence from work, worker compensation, rehabilitation and surgical costs, and cost spent on preventive measures.

How much money is spent preventing RSI?

Today more and more money is being spent on the prevention of RSI, as employers and government become increasingly aware of the size of the problem. Ergonomics is one way of helping prevent RSI research suggests that for every $1 invested in ergonomics intervention strategy (RSI prevention) there is a return of about $17 (Buckle 1999 cited RSIA). Ergonomic solutions range from arm rests and ergonomic keyboards that cost around $100 up to complete ergonomic workstations costing several thousand dollars.

What are the preventive measures?

There are countless varieties ergonomic aids to reduce the chances of developing RSI. Some of these include keyboards, monitors, adjustable desks, arm and wrist supports, ergonomic mice, ergonomic chairs and so on. There is also a wide selection of software that prompts the user take breaks from their workstation.

Do these measures work?

The effectiveness of most of these measures is disputed. No studies have shown any of these measures to be effective in preventing RSI so far. However, it is likely that some do contribute to a more comfortable work environment. Some arm and wrist supports will alleviate some stress on the muscles and a well set up workstation will encourage healthy work habits and posture. Some software programs have been shown to be effective, but in practice the user will usually not adhere to the programs requests to take a break. Furthermore the user often finds this method to be an interruption to their work.
The benefits of taking breaks has been proven effective to relieve muscle fatigue and tightness.

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Taking breaks or pauses as a prevention to RSI.

There is a lot of information available on the effectiveness of taking breaks to prevent RSI. Since this the only known effective measure so far, it will be discussed in detail.

What are micropauses?

There is a lot of information available on the effectiveness of taking breaks to prevent RSI. Since this the only known effective measure so far, it will be discussed in detail.

What are mini-breaks?

Mini-breaks are breaks that are typically 1-2 minutes in length and should be taken at least twice an hour. At least once an hour try to change what you are doing for about five minutes, either by changing your posture or just by varying you movements.

What are the effects of taking breaks?

The benefits of taking breaks have been proven to reduce the incidents and severity of RSI
It helps in several different ways firstly by reducing muscle fatigue, secondly it allows oxygen to flow through the muscle tissue more freely and thirdly it reduces overall stress on the body. (R.S.I.A.)

How many breaks should be taken?

The amount of breaks that should be taken depends on how intense the task being performed is. Generally the best advice for someone performing data entry is to take a total of at least 10 minutes break every hour in the form of micropauses and mini breaks. These breaks are in addition to your normal daily breaks eg. morning, lunch, afternoon.

How does software help?

There are numerous companies manufacturing software designed to remind the computer user to take frequent breaks. Some of the software has pop-up reminders that can be set to block use when a break is required. This software is effective if used correctly as the benefits of taking breaks are proven.

Is software effective to prevent RSI ?

This method of reducing R.S.I. is usually installed in environments where there is an increased risk of developing a problem. These environments have high workloads and are often subjected to deadlines. Due to this fact the software wil sometimes be ignored, therefore reducing the software’s effectiveness. If the software is setup to block the user when reminded, users will often have their chain of thought interrupted and normal work rate disturbed. This is a frequent reason for the user to turn the software off.

References - Repetitive Strain Injury Association {RSIA}
- Occupational Safety and Health Administration {OSHA}
- European Union Labour Force {EULF}
- Bureau of Labour Statistics {BLS}

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