Upper Limb Disorders include a range of disorders that affect the arms, hands and neck - in fact any of the upper limbs of the body that could suffer from incorrect posture, strains or repetitive injuries. These disorders are usually appear as aches, pains, tingling and other sensations, but there is a wide variety of signs and symptoms for each kind of disorder.
Musculoskeletal Disorders and Upper Limb Disorders
The term 'Musculoskeletal Disorders' is used to cover a very wide range of ill-health conditions that affect the structures of the body: the bones, tendons, muscles and other tissues. These disorders can be caused through physical force, repetition, vibration and posture constraints. Upper Limb Disorders are Musculoskeletal Disorders.
In a work environment, such disorders can cause significant losses through time off and sickness absence, and result in reduced productivity through poor morale. These issues are of similar importance in volunteer situations, where those people who are suffering might be less likely to continue volunteering or need to reduce their duties. In fact, more people suffer with longer-term health issues that suffer accidents in most work situations.
Some kinds of Upper Limb Disorders (ULDs) are well known, such as Carpal Tunnel Syndrome, Tennis Elbow and Vibration White Finger. Repetitive Strain Injury (RSI) is often used as a term for a range of ULDs that have been caused by repetitive movements, such as the hand movements of a typist. However, this term is becoming less used as the individual disorders and diseases are becoming more recognised.
As part of the Risk Assessment that is completed, these three aspects of the work should be analysed as to whether or not there is a risk posed to the person. More detail about each of these areas is included in the below paragraphs.
Constraints placed on a person's ability to move freely and comfortable can lead to aches and pains and could develop into longer-term disabilities. Similarly, tasks where a person has to take up an unnatural posture for some the time can lead to injuries as well. As such, it is important to ensure that people can keep to a position that is as comfortable and natural as possible and recover from any short-term work that is in cramped or uncomfortable positions.
Some typical problems include stooping down or over stretching (in any direction) to reach something needed for a task or to view something, such as a screen. This can be overcome by placing objects in more accessible (or more comfortable) places. People might also be forced into unnatural positions if the lighting is poor as they move to make the best of available lighting.
Pressure could be placed onto the hands when gripping badly designed handles and hands could be over-stretched, for example by using scissors that are too large for the person's hand. Consider also the 'handedness' of tools and objects – most items are designed for right-handed use, and left-handed people might find these hard to use effectively.
Where the task allows, people should be seated. When seated, people need space in front of them to allow their legs to reach comfortably onto the floor and enough knee room needs to be available. Seating should be adjustable (especially if using a computer screen) and a footrest can be used if a person finds this more comfortable.
One important factor to consider is the individual needs of the person – each and every person is a different size and has different strengths and abilities. As with any task, part of the Risk Assessment should include a discussion with the person or people carrying out the task to ensure that all issues can be addressed.
Care should be taken when choosing items which have 'ergonomic' in the title. Many tools and pieces of equipment are designed for the 'average' person, and an individual might not fall within this definition. One person's ergonomic tool is another person's long-term illness.
Finally, consideration should be given to the person's own inherent posture. It is true of today that most people's posture is far from good, in fact this itself could lead to many longer-term health issues.
A high repetition rate can lead to an injury as the muscles are not given adequate time to relax and recover. Any task that needs similar, repeated actions every few seconds or for most of the working day could lead to injury (including Repetitive Strain Injuries). A very common example of such repetitive action is the use of a computer keyboard.
If force is needed in these actions, such as when using a hammer, this might increase the risk of developing a ULD, even on shorter tasks. There is also an increased likelihood of injury if the hand is used to provide force directly. Take as an example typewriters, which needed some force to operate, and compare that with today's modern soft-touch keyboards.
People that carry out highly repetitive tasks, including those that do not involve much force such as typing on a keyboard, should be encouraged to take regular rest breaks. This break might be a planned rest break or is could be a break to to carry out a different task.
If people act as a team, encourage them to alter their work or rotate the tasks between the people, providing that the tasks are not so similar that they use the same kinds of movements.
Some tools and equipment vibrate or have vibrating parts. Not only can this be a noise nuisance to the person, but these vibrations can cause other health concerns. Hand-Arm Vibration Syndrome (HAVS) is one disorder that is caused by repeated exposure to vibrating hand tools (amongst other causes). Another common disorder relating to vibrating equipment is Vibration White Finger, which can be disabling.
The first warning signs that something has the potential to lead to a vibration disorder is a numbness or loss of dexterity in the hands after using a piece of equipment. This is worse when the temperature is cold (due to the restricted blood flow around the body, especially in the fingers).
The most effective way to control vibration is to choose power tools carefully. Most modern power tools are designed with anti-vibration features, and such tools need to be maintained in order to keep these features working correctly (such as by lubricating moving parts). It is unlikely that older tools and equipment would have such features built into the design. Additionally, many domestic tools do not comply with the more stringent standards that have been set for industrial tools as it is anticipated that the frequency and duration of use would be much lower.
On cold days, the dexterity and numbness problems can be improved by wearing warm gloves, which can also help to prevent the onset of vibration-related disorders at it maintains the blood flow in the smaller blood vessels in the hands and fingers. However, no gloves provide protection against vibrations very effectively, as there is a tenancy to over-grip the item to compensate, which will transmit the vibrations through the musculoskeletal system better than if the person were to provide a normal grip without gloves.
Another form of vibration-related disorder is Whole Body Vibration, which can cause back pains and other injuries. Sitting or standing on something that vibrates, such as a sit-on lawn mower, can cause these especially if the manufacturer's design does not consider the effects of vibration on the person. Again, most modern equipment has features build in to limit the vibrations that affect a person using the equipment.
If vibrating equipment is used extensively, say for grounds maintenance, a further assessment might be necessary using vibration-sensing dose-meters. These can be affixed to the appliance or equipment in question, and provide a go/no-go indication or dose of exposure to vibrations. This is better than relying on manufacturer's data which usually is adequate for new equipment only.