Muscle & joint problems from Computer Work

If you have not completed HSAS on-line Display Screen Equipment training and assessment, please contact the HSAS team to register. mailto:safety@essex.ac.uk

Symptoms

Sedentary work at a computer increases the risk of problems in the neck and shoulders, as well as the hands, wrists, arms and elbows (upper limbs).

Early symptoms such as niggling dull aches or discomfort are initially relieved following short breaks from work. However if ignored, the discomfort may become more persistent despite rest and be accompanied by other symptoms such as:

• tenderness or burning sensation
• shooting pains, often from the wrist into the elbow
• numbness or tingling
• pins and needles
• painful or reduced grip
• swelling
• muscle spasms

The onset of symptoms may occur when feeling particularly pressured or stressed, whether from personal anxieties or work concerns. Headache and migraine can also be triggered by tension in muscle as the result of psychological pressures.

Problems may be noticed following a return to work after a long break; after periods of intensive keyboard or mouse work; when under pressure to complete work to tight deadlines; when interest and absorption in work reduces awareness of posture and the need for frequent screen breaks.

Causes

Keyboard workers are particularly vulnerable to muscular pains or problems with joints and tendons because of the prolonged static muscular effort, required to support upper limbs in fixed or awkward postures during keyboard and mouse use.

Key factors known to increase the risk of muscle and joint problems are:

• Poor sitting posture
• Keying or using the mouse with arms/elbows extended forward
• Working too long without breaks
• Poor typing technique
• Feeling pressured and tense

Action to Take

Awareness of existing work posture and practice is essential to identify changes that should be made to reduce the risk of foreseeable musculoskeletal problems from your work at the computer.

1. Adjust your chair

- every day before starting work, but also throughout the day. Ensure your chair is adjusted to support upright posture, allowing your back, shoulder and neck muscles to relax whilst sitting static.

Sitting Posture

• Use the chair for support, not the desk - sit well back into your chair; adjust the height of the chair back to fit into the small of your back, low enough to support your pelvis in a forward tilt.
• Let the chair take the strain - use the tilt adjustment to recline the back support sufficiently to allow your back and neck muscles to relax, whilst maintaining an upright posture.
• Sit tall - with your head balance squarely on your shoulders, keep your shoulders relaxed and elbows tucked close by your sides.

Keying Posture

• Raise the height of your chair so your elbows are above the desk level.
• Use a footrest if your heels are now not touching the floor.
• Sit close to the desk, keep your elbows tucked in at your sides when typing or using the mouse. Ensure your upper arms are free to hang vertically down from your shoulders.
• If the arms on your chair prevent this, use a chair without arms or see if the arms can be safely removed.
• Lift your wrists to type, keeping your hands in alignment with your arms. Only rest your wrists on the edge of the desk when not typing or better still, relax your arms by your sides or do stretching exercises.

2. Reposition Equipment

Ensure you have first adjusted your chair to support an upright but relaxed posture. Then position your display screen equipment to ensure you can maintain that correct posture whilst working.

If you use a laptop for more than an hour at a time, always use an additional keyboard and mouse, which will ensure you can maintain the correct posture for keyboard/screen work.

Keyboard and Mouse

Relax against the chair back, keep your elbows close to your sides and draw your chair close to the desk. Bring your keyboard and mouse close to the desk edge, leaving sufficient space to rest your wrists when not keying.

If you need to look at your fingers to key, avoid dropping your head forward. Instead remain upright, using your chair for support, pull your chin in and lower your eyes (not your head) to view your keyboard.

Lift your wrists to key, keeping them straight, not flexed back. A wrist support should only be used when at rest. Avoid mouse use by using keyboard shortcuts instead. If you must use the mouse be careful to hold it lightly with a relaxed hand when in use. When not operating the mouse, release your hold and relax your arm or do some stretching exercises.

Computer Screen

Position the screen straight in front of you. You should not view the screen with your neck twisted to one side.

Maintain the correct sitting and keying posture described earlier and position your screen so you can view it with relaxed eyes, looking down as you would for comfortable reading. The top of the screen should be no higher than your eyebrows, to reduce visual fatigue and the risk of neck problems.

A comfortable viewing distance is generally 50-60cm (20-24"), but this is determined by your vision and whether spectacles are worn. Single focus lenses are preferable for screen use. Varifocals are not recommended as they can cause neck problems. If you do wear varifocals, make sure your screen is positioned so that you do not need to extend your neck to get the screen in focus.

Workstation environment

To avoid uncomfortable glare (from bright sunlight) or reflection (mirror image of window/reflected sunlight) when viewing your screen, ensure you do not face into, or have your back to, a window.

Position you computer workstation away from the window, if at all possible and at right angles to it, to reduce the risk of these problems.

3. Work Smart - Take a Break

Long periods of uninterrupted keyboard/screen work greatly increase the risk of muscular problems and pain, as a result of remaining static whilst muscles are tense.

Frequent short breaks from your screen are better than longer infrequent ones. Plan your day to break up longer spells at your keyboard with other varied tasks.

Do not:

• sit static at your computer for longer than an hour without changing your posture, or taking some exercise away from your screen.
• hold on to your mouse unless you are actually using it, but let go and allow your arm/hand to relax between use
• reach forward to lean your arms on your desk; instead rest back against your chair for support.
• put up with pain or discomfort, but seek help immediately to identify the posture and work factors putting you at risk.

Do:

• adjust your chair daily, ensuring an upright posture with support in your lower back
• reduce mouse use and instead learn to use keyboard shortcuts
• plan your work, so you have reason to change your posture or do a different task every 50-60 minutes
• look for opportunities to stand up, arch your back and stretch your spine, or go for a short walk to get your circulation going
• create mini-breaks from keying/mouse work by doing these seated stretching exercises

If you have followed all of the above advice but continue to experience problems, you should contact the Occupational Health Adviser (Tel: 3793; Email:shawkins) without further delay.

4. Keying Technique

Become keyboard competent by learning to touch-type. This will reduce the risk of health problems as:

• you will then look at the screen instead of at your hands - reducing the risk of neck tension
• you will use all your fingers to type and are more likely to have a light touch on the keys - reducing muscle tension in your dominant hand and forefingers
• you will work more efficiently and spend less time correcting errors - which will help reduce pressure and increase job satisfaction

Click here to access online touch typing course

5. WORKING UNDER PRESSURE

Studies have shown that psychological risk factors are of equal importance to physical risk factors in influencing health, in particular musculoskeletal health.

Feeling pressured or stressed increases the risk of physical tension and discomfort. Coping with particularly stressful demands, whether at work or at home, can influence behaviour which may increase the risk of health problems. For example, an individual may forego rest breaks in an effort to cope with high workload or tight deadlines.

Here are some question you may need to consider and discuss with your manager, to manage work pressure appropriately:

1. Are there ways of pacing your work better - to introduce more control over your work rate?
2. Does your system of work encourage you to skip meal breaks to finish earlier or keep on top of the workload?
3. Have you sufficient training and information in order to complete your work successfully?
4. Do you feel there is support from supervisors/managers and colleagues?
5. Do you work overtime that is unplanned, unmonitored and/or not organised to minimise the risk of upper limb problems?
6. Do tasks require high levels of attention and concentration?
7. Do you have any control over the way you work?
8. Are there frequent tight deadlines to meet?
9. Are there sudden, or seasonal, changes in workload or volume without the mechanism to deal with the change?
10. Do you have existing health problems you find difficult to manage at work?

Check the Work related Stress page for more information on how to cope with these demands.

Further information:

Stretching exercises for computer users

Workstation assessments: contact the HSAS team (Tel: 2399; email: ohqueries) when you start work and whenever there are substantial changes to your workstation.

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