Occupational Health Service

Don't Feel the Strain

Work related Upper Limb Disorder (WRULD) is an umbrella term for conditions that may affect muscles, tendons, nerves or joints (i.e. the soft tissues) of the upper limbs in a working environment.

The term has largely replaced the old expression 'Repetitive Strain Injury (RSI)', which is not a recognised medical phrase and is similar to 'sports injury' in that it suggests how the injury occurred but says nothing about the injury itself, i.e. what is actually wrong.

Any part of the body that is subjected to repeated high frequency or forceful use may develop symptoms due to inflammation, swelling or pressure on local tissues. Environmental circumstances such as cold, vibration, poor or awkward posture and stress may increase this tendency.

There are many well-defined specific conditions affecting the upper limbs, such as Tennis Elbow, Carpal Tunnel Syndrome and De Quervain's Tenosynovitis. There are also a group of nonspecific upper limb conditions where pain or 'pins and needles' are present but a definitive problem in the muscle, nerve, tendon or joint cannot be found. The cause of these conditions is uncertain but it has been suggested that local muscle fatigue or poor upper back or neck posture may be contributory.

It is worth remembering that virtually all of the conditions we see in working environments can also occur from other activities such as certain hobbies, DIY work or even general domestic routines. Many of the conditions described under the WRULD heading can also occur as a result medical conditions that are not activity related, e.g. Carpal Tunnel Syndrome may occur in Rheumatoid Arthritis and pregnancy.

Risk Factors
WRULDs are unlikely to have one single cause. In most cases, a mixture of factors will combine to result in a WRULD-type condition. Some of these factors, the primary factors, are mainly to do with the environment. However there may 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
• a cold working environment

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 may contribute to this process.

A large number of people work in an office environment and use computers at the work place. The Safety, Health and Welfare at Work (General Application) Regulations, 1993, Part VII "Work with Display Screen Equipment" lay down the health and safety requirements aimed at protecting VDU users against visual, postural and stress problems associated with their use. The following are some practical tips to setting up and adjusting your work station. (adapted from HSA VDU Guidelines):

1. Feet firmly on the floor or supported by a footrest
2. Knees bent at about 90 degrees
3. Keyboard flat or slightly inclined
4. The head should not be tilted back or too far forward
5. Shoulders relaxed
6. Maintain the natural curve of the spine
7. Lower back supported by the chair
8. You should be able to sit back in your chair with your hips fully supported
9. The front edge of the seat should not push against the knees
10. When using the keyboard your elbows should be slightly bent with your forearms parallel to the floor and your wrists almost straight.

Getting Comfortable, Posture and Breaks

• Adjust your chair and VDU to find the most comfortable position for your work. Make sure you have enough workspace to take whatever documents or other equipment you need.
• A document holder may help you avoid awkward neck and eye movements.
• Adjust your keyboard to get a good keying position. A space in front of the keyboard can be helpful for resting the hands and wrists when not keying.
• Try to keep your wrists straight when keying. Key a soft touch on the keys and do not over stretch your fingers. Good keyboard technique is important.
• Position the mouse within easy reach so it can be used with the wrist straight.
• Do not sit in the same position for long periods. Make sure you change your posture as often as practicable. Some movement is desirable, but avoid repeated stretching to reach things you need (if this happens a lot, rearrange your workstation).
• Most jobs provide opportunities to take a break from the screen, e.g. to do filing or photocopying. Make use of them. Frequent short breaks are better than fewer long ones. EM

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