ib9 musculoskeletal risks and control

8/12/2019 IB9 Musculoskeletal Risks and Control

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IB9 Musculoskeletal risks and control

Element B1: Musculoskeletal risks & control

Learning outcomes:

On completion of this element, candidates should be able to:

Outline type causes and relevant work place examples of injuries and ill healthconditions associated with repetitive physical activities, manual handling and poorposter.

Explain the assessment and control of risks from manual handling,repetitive activitiesand poor poster.

Minimum hours of tuition: 4 hours.

1.0 Ergonomics

Understanding ergonomics at workYou may have come across the term ergonomics. People sometimes refer to it as human factors.Not everyone really understands what ergonomics is, what it does, or how it affects people.

What is ergonomics?

Ergonomics is a science concerned with the fit between people and their work. It puts people firsttaking both their limitations and capabilities into account. Ergonomics sets out to ensure that tasks,equipment, information and the environment suit each worker.

To assess the fit between a person and their work, ergonomists have to consider many aspects,including:

the job being done;

the demands on the worker;

the equipment used (its size, shape, and how appropriate it is for the task);

the information used (how it is presented, accessed, and changed)the physical environment (temperature, humidity, lighting, noise, vibration);

the social environment (such as teamwork and supportive management).

Ergonomists consider all the physical aspects of a person, such as:

body size and shape;

fitness and strength;

posture;

the senses, especially vision, hearing and touch;

the stresses and strains on muscles, joints, nerves.

Ergonomists also consider a persons psychological aspects, such as:

mental abilities;

personality;


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knowledge;

experience.

Assessing physical aspects, jobs, equipment and working environment and the interaction betweenthem enables ergonomists to design safe, effective and productive work systems.

Applying ergonomics to the workplace reduces the potential for accidents, ill-health and injury andimproves performance and productivity.

AccidentsIn the design of control panels, consider:

the location of switches and buttons - switches that could be accidentally knocked on or offmight start the wrong sequence of events that could lead to an accident;

expectations of signals and controls - most people interpret green to indicate a safecondition. If a green light is used to indicate a warning or dangerous state it may be ignoredor overlooked;

information overload - if a worker is given too much information they may become confusedmake mistakes, or panic. In hazardous industries, incorrect decisions or mistaken actionshave had catastrophic results.

Ill-health

Controls and equipment should be positioned in relation to how they are used. Those used mostoften should be placed where they are easy to reach without the need for stooping, stretching orhunching.

Failure to observe ergonomic principles may have serious repercussions, not only for individualsbut whole organisations. Many well-known accidents might have been prevented if ergonomics hadbeen considered in designing the jobs people did and the systems within which they worked.

Ergonomics is typically known for solving physical problems. For example, ensuring that worksurfaces are high enough to allow adequate clearance for a workers legs. However, ergonomics

also deals with psychological and social aspects of the person and their work. For example, aworkload that is too high or too low, unclear tasks, time pressures, inadequate training, and poorsocial support can all have negative effects on the person and the work they do.

Here are some examples that highlight typical ergonomic problems found in the workplace:

Display screen equipment

The screen is poorly positioned - it is too high/low/close/far from the worker, or is offset toone side.

The mouse is placed too far away and requires stretching to use.

Chairs are not properly adjusted to fit the person, forcing awkward and uncomfortablepostures.

There is glare on the screen from overhead lights or windows, increasing the risk ofeyestrain.

Hardware and/or software are not suitable for the task or the person using it, causingfrustration and distress.

Not enough breaks or changes of activity.


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These problems may result in mistakes and poor productivity, stress, eye strain, headaches andother aches or pains.

Manual handling

The load is too heavy and/or bulky, placing unreasonable demands on the person.

The load has to be lifted from the floor and/or above the shoulders.

The task involves frequent repetitive lifting.

The task requires awkward postures, such as bending or twisting.

The load cannot be gripped properly.

The task is performed on uneven, wet, or sloping floor surfaces.

The task is performed under time pressures and incorporates too few rest breaks.

These problems may result in physical injuries such as low back pain or injury to the arms, hands,or fingers. The problems may also contribute to the risk of slips, trips, and falls.

Work-related stress

Work demands are too high or too low.

The employee has little say in how they organise their work. Poor support from management and/or colleagues.

Conflicting demands, e.g. high productivity and quality.

Poor control of the risks causing work-related stress could lead to ill health and reducedperformance and productivity.

Managing the working day

Not enough recovery time between shifts.

Poorly-scheduled shifts.

Shifts that clash with domestic responsibilities.

Excessive overtime worked by employees.

These problems may lead to tiredness or exhaustion, which can increase the likelihood of accidentsand ill health.

There are many ways in which ergonomic problems can be identified. Ideally, several approachesshould be used:

Employees should be approached and their views sought. They are the best-placed to advise onthe work they do, the problems they may have and the impact of those problems on health, safetyand performance.

The work system should be assessed, using a series of simple questions such as

Is the person in a comfortable position?

Does the person experience discomfort, including aches, pain, fatigue, or stress?

Is the equipment appropriate, easy to use and well maintained?Is the person satisfied with their working arrangements?

Are there frequent errors?


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Are there signs of poor or inadequate equipment design, such as plasters on workers fingersor home-made protective pads made of tissue or foam?

If there are frequent errors and incidents where mistakes have occurred and people have beeninjured, the circumstances surrounding them should be examined thoroughly. It is highly likely thatthere will be clues to the causes of those incidents in what has happened. Accident reports can bevery useful in identifying details of incidents and their possible causes. Examination of sicknessabsence and turnover records may also highlight areas for investigation.

If the employer thinks that an ergonomic problem has been identified, they should look for likelycauses and consider possible solutions. A minor alteration may be all that is necessary to make atask easier and safer to perform. For example:

provide height-adjustable chairs so individual operators can work at their preferred workheight;

remove obstacles from under desks to create sufficient leg room;

arrange items stored on shelving so those used most frequently and those that are theheaviest are between waist and shoulder height;

raise platforms to help operators reach badly located controlschange shift work patterns; and

introduce job rotation between different tasks to reduce physical and mental fatigue.

Employees should be consulted and their suggestions and ideas solicited. If they are involved fromthe start of the process, this will make it more likely that they will accept any proposed changes.

Any alterations should be properly evaluated by those who actually do the job.

Care should also be taken that a change that is introduced to solve one problem does not causedifficulties in another part of the workplace.

It is not always necessary to consult ergonomics professionals, and the expense of making changescan often be kept low. However, if a straightforward solution cannot be found, professionaassistance is often the next step.

Ergonomics input does not necessarily involve high costs, and can save money in the long term byreducing injuries and absence from work.

An understanding of ergonomics in the workplace can improve the daily work routine. It is possibleto eliminate aches, pains, and stresses at work and improve job satisfaction. Ergonomic solutionscan be simple and straightforward to make - even small changes such as altering the height of achair can make a considerable difference.

Question: Outline the meaning of the term ergonomics.

Outline the ill health effect arise from poor ergonomic design.

1.1 Work-related Upper Limb Disorders and the Risk Factors

A Guide to Work-Related Upper Limb Disorders (WRULDs).

Definition:

The term WRULD is used here as synonymous with Repetitive Strain Injury, Cumulative TraumaDisorder etc. It is a somewhat vague term under which a large variety of conditions and symptoms


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are classed. A fundamental distinction can be made between those conditions with a specificrecognised medical diagnosis and those of a so-called 'diffuse' nature, which still lack a clear-cutdiagnosis. Within the first category, the non-diffuse group, the following conditions are frequentlyencountered:

carpal tunnel syndrome;

tendonitis;

tenosynovitis;

de Quervain's syndrome;

tennis elbow;

thoracic outlet syndrome and others.

All these are 'classic' conditions, well-recognised, with prescribed clinical tests and clear-cuassociated symptoms. This is in contrast to the diffuse group of conditions which largely escape theclinical tests and sophisticated medical investigation. The factors that are consistent in this groupare:

similarities in individuals' causative history;

similarities in individuals' symptoms and symptom behaviour;

often disappointing results to non-diffuse type treatment.

The diffuse group of conditions is characterised by a range of symptoms (ache, pain, tingling,cramps, numbness, heaviness, tightness and others) which tend to vary in location, intensity andnature. It is typical for symptoms to 'jump around' and once established, to appear spontaneouslywithout obvious trigger or cause. Symptoms are often felt 'deep' in the tissues, and can be hard todescribe by those who experience them. Another aspect can be the emergence of symptomsgenerally associated with the sympathetic nervous system. Examples include the reporting ofheaviness, hands feeling hot or cold, swelling and tightness, usually without any visible signs.

In contrast with conditions such as 'tennis elbow' and carpal tunnel syndrome, the structure at fault

is not easily identifiable. Difficulties with diagnostic tests and changing symptoms have in the pastled some people to believe that this condition is predominantly 'in the mind' rather than reflecting aphysical injury. Even though psychological factors do play a role, recent research has clearlyidentified measurable nerve function deficits.

In spite of the wealth of information and opinions on diffuse WRULDs, the current medicalunderstanding of exactly how this condition is caused, of what the damage consists and how todetermine a prognosis, is still very limited. However, three groups of risk factors have beenidentified and are generally accepted as such.

These are:

static muscle loading;

overuse and repetition; stress.

These risk factors are identical for both the diffuse and the non-diffuse conditions. There isanecdotal evidence to suggest that people using the keyboard and mouse are more likely todevelop a diffuse condition. Those working in an industrial setting seem to be more likely to developa more specific form of WRULDs. This is likely to be related to the different 'mix' of risk factors inthese settings.


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Static muscle loading.

Static muscle loading describes muscular activity, which focuses on holding an object, or onmaintaining a certain posture or position which involves little or no movement. The problem with thisform of activity is related to the muscle structure and the way muscles work. For muscles to be ableto contract, they require energy which is delivered to them via the blood circulation. When musclescontract, they effectively compress the blood vessels which feed them and if a contraction ismaintained for any length of time, as during static activity, their blood supply is reduced and a build-

up of waste products can accumulate. This results in muscle fatigue and can be experienced as anache or discomfort. Computer work tends to be more static and less varied than clerical oradministration work, and can cause static muscle loading in a variety of body areas unless regularbreaks and changes in activity occur. When using the keyboard, static muscle work is required tohold the arms and hands in place. Furthermore, if the back is not well-supported, static muscleactivity will occur there and in the muscles of the neck. Over time, this can lead to localised muscletightness and postural imbalances, which can compromise the blood supply and the nerve functionin the arms and hands.

Overuse and repetition.

Overuse of specific muscles and repetition of certain activities can carry the risk of straining tissuesbeyond their normal capacity. Initially, fatigue occurs and if demands increase or sufficient changesin activity or breaks are not provided, aches, pains and injury can result. Any repetitive taskperformed continuously without sufficient breaks or changes in activity will place demands onspecific structures and result in a risk of injury.

The way in which an activity is performed will affect the likelihood of a problem occurring. Takingcomputer work again as our example; more specifically, the angle of the wrist while typing or usingthe mouse; we can see that with wrists in a neutral position, the risk of an overuse problem isgreatly reduced compared with typing or using the mouse with wrists extended or deviated. This isdue to the affected structures working in a neutral, relaxed position, causing minimal compressionor stretch and requiring minimal effort and muscle activity.

Stress.

Stress and other psychological factors, perhaps surprisingly, can play an important part in the onsetand experience of WRULDs too. This is due to stress causing increased muscle tension andgenerally sensitising the nervous system, which leads to an increased perception of pain. Stressfactors, whether related to work, family or any other area, can therefore be important contributors toWRULDs.

Pathology.

Which parts of the body are actually affected and how can the often-varying symptoms beexplained?

Different structures have been suspected of causing the pains associated with WRULDs and nowthere is strong evidence that the main site of injury and symptom generation is the nerves ratherthan muscles, tendons or joints. Although a tendinitis, muscle strain or joint problem may coexist,the real cause of the diffuse pains appears to be located in the nerve structures. A combination ofnerve compression, reduced blood supply and over-excitation through the body's stress response isbelieved to cause a low-level inflammation of the nerves. This in turn alters the functioning of theseneural structures, generating any of the symptoms listed earlier. As a result, normal touch cancause discomfort and gentle movements can become acutely painful. As the nervous system itself


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is affected, symptoms can vary greatly. No longer do these nerves simply transmit the informationits receptors pick up, but they may distort the messages and can even generate their own.

Treatment.

Frequently, people with WRULDs seek treatment only when the symptoms start to seriouslyinterfere with their work, or when their pains persist even during rest. This is unfortunate as earlyintervention produces the best and fastest results. In our experience, the most effective treatmentlies in a combination of hands-on techniques, exercises, relaxation, good workstation ergonomics

and advice on posture and work pacing. Rest alone does not cure WRULDs; it may at best settlethe symptoms temporarily. However, prolonged rest will lead to a deconditioning and weakening ofthe muscles and associated structures.

Before embarking on an exercise regime, it is advisable to have an assessment by aphysiotherapist who is specialised in the treatment of these disorders to ensure appropriateexercises are given. From an initial assessment, the therapist should be able to determine the mainunderlying contributory factors and develop an appropriate treatment programme for eachindividual. During the course of treatment, the symptoms experienced by the individual oftenchange. An experienced therapist is able to interpret these changes and to adjust and progress thetreatment accordingly. As these disorders take some time to develop, they tend to take time toresolve and often require changes in work pattern and in postural or tension habits. Thereforetreatment can continue over a longer period of time than initially expected.

At times, when a person is first assessed, his or her symptoms are quite acute. As the symptomsease, the treatments are spread out over time with emphasis being placed on self-management.This should allow for new postural and work habits to be formed and a set of exercises to be carriedout regularly. There is no standard treatment period: for some people who seek treatment early,three or four sessions are sufficient; for others who have developed a more chronic problem,treatment may continue for a number of years with appointments at three- or six-monthly intervals.

The physiotherapy techniques that have been found to be most effective include:

neural and spinal mobilisation;

soft tissue techniques; postural and muscle imbalance work.

Exercises are a crucial part of treatment and a specific programme should be developed for eachindividual to follow. This should include exercises to be used both at home and at work. Taking upsome form of general exercise is often recommended. This can involve gentle gym workouts,swimming or organised classes. As a rule swimming, yoga, gentle stretch classes and walking arepreferable to racquet sports and weight training.

People with an established and chronic condition will benefit from a formal work rehabilitationprogramme, which will progressively increase the tolerance to the critical activity.

Prognosis.

Most people with WRULD make a good recovery with appropriate treatment. Some need a longtime and some might have to limit or space out particularly straining tasks. Factors that affect theprognosis are:

The duration of WRULD symptoms.

The intensity and spread of symptoms.

The time it takes symptoms to ease when stirred up.


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There may also be underlying postural problems such as a long-standing old back injury or analtered spinal curvature that can affect the prognosis. The work in which people are involved andtheir ability to manage it, allowing sufficient rest periods or avoidance of specific tasks, will also beof importance as may stress or psychological factors.

Posture.

Posture is the position of the parts of your body in relation to each other. Your posture constantlychanges, depending on the activity; but no matter what you are doing, there is a way of holding and

moving your body that is balanced and efficient. This is called good posture. It is a state of muscularand skeletal balance which protects the bones, ligaments and muscles of the body against injury orprogressive deformity. Good posture makes movement more effective and more energy-efficientwhilst minimising stress. We talk about the body being in balance. If someone has good posture instanding, for example, when measuring muscle activity in this position, you will find there is almostnone to be recorded, because the skeletal frame is perfectly balanced and does not requireadditional support from the muscles.

Your posture is second nature to you, a taken-for-granted habit. If you have poor posture, probablyothers are more aware of it than you are. You may be aware only of chronic fatigue, headaches orbackaches which can stem from poor posture. Poor posture causes muscular strain, particularly ofthe spinal muscles and therefore wastes energy. It produces uneven stress on spinal joints anddiscs and may cause permanent damage.

When postural habits are good, you can work and play longer without fatigue because your muscleswork more efficiently. Your spine has a chance to develop normally and your internal organsfunction better. You look healthier and happier, your clothes fit better, and you make a betterimpression on others.

Poor postural habits can lead to secondary problems, e.g. stiffness of the joints in the mid/upperback and hip, excessive movement of the joints in the neck and low back, pressure on nerves,lengthened and weakened muscles or tightened and overly strong muscles. All of these canproduce pain and disability and destroy the natural balance of the body.

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1.2 This state of "perfect balance" is best achieved by:-

This state of "perfect balance" is best achieved by:-

Avoiding a poking chin position and keeping your head level so that a perpendicular line droppedfrom just below your eye will hit your collar bone. This should have the effect of lifting your breastbone up a little and make you stand a bit taller.

Allow your shoulders to relax so that the arms hang loosely by your sides.

Tighten your stomach muscles as hard as you can without holding your breath, then let them relaxby just over half. Try to maintain that level of tension as you go about daily activities.

When standing or sitting, get into the habit of tightening the backside muscles. Hold for 10 to 15seconds, then relax. Try to consciously tighten them a little when walking. You will find that if youuse your stomach muscles as suggested, then your bottom muscles will automatically work morewhen you are walking.


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When you stand, your lower back should curve slightly. This curve, called a lordosis, helps todistribute your weight properly through the spine and pelvis. The discs located between each of thevertebrae act as shock absorbers. Excessive pressure within the discs may, when sitting, causedamage, but this can be avoided through proper posture.

The knees should be straight but not locked, stomach flat, ribs raised, shoulders and head erect.Pretend you are balancing a book on your head. Your weight should be evenly distributed on bothlegs. You should be relaxed, not as though you are on sentry duty.

Walk tall with your feet pointing straight ahead. Your arms should swing freely from your sides. Lookstraight ahead; never down.

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1.3 Sitting Posture

As you sit, your pelvis rotates and the lordosis or low lumbar curve is flattened. Good seats andproper sitting posture help reduce this effect and ease the pressure on the discs. Sit tall with bothfeet flat on the floor, your whole back against the chair back, and your head erect. Your weightshould be evenly distributed on both buttocks.

Good seats and how to use them.

At home: make sure your back is supported comfortably. Use arm rests if available. If you are sittingfor long periods, shift your position from time to time.

At work: Avoid hunching forward; if using a stool, place it close to your work surface, so as to restyour arms comfortably. Also, use the height adjustment if available to assure comfortablepositioning.

While driving: Move the seat far enough forward to allow knees and elbows to be slightly bent asyou reach for the steering wheel and pedals. Use added low back supports if needed.

Avoid:

using straight-back chairs with no low back support;

slouching while driving;

using soft seats, such as sofas;

using flat stools with hard surfaces and no height adjustments;

reaching for your work; instead, move your stool close enough to the work surface to allowcomfortable positioning;

putting seat too far back or forward;

using flat seat backs unless a supportive cushion can be used.

1.4 Managing WRULDs- according to the Health and SafetyExecutive:


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WRULDs can be effectively managed in the workplace by:

assessing the risks - this means looking around your workplace to see which jobs may causeharm;

reducing the risk of WRULDs - this could mean changing the way work is organised;

helping sufferers back to work.

Assessing the risks of WRULDs in your workplace

To help you find out which tasks are risky, watch workers as they carry out their jobs, ask themabout any problems and check any illness/injury records. The main areas that are likely to increasethe risk of WRULDs are listed in the table below. They can interact with each other to increase therisk.

1.5 Reducing the risk of WRULDs

If your investigations (known as a risk assessment) show that there is a problem, the followingsection provides some helpful suggestions for reducing the risks. A few general tips are:

Changes do not necessarily need to be expensive. Simple and low cost changes can often beeffective.

Try to consider risk when setting up new workstations. It is cheaper than redesigning them orpurchasing more suitable tools at a later stage.

Tackle the serious risks or those that affect a large number of workers first.

Try to make the task and workstation suitable for each worker, rather than make the worker adaptto fit the task and workstation.

Test any changes on one or two workers before making changes for everyone.

1.6 Dealing with WRULDs

It may not be possible to prevent all cases of WRULDs, because workers respond differently to therisks. Anyone with a WRULD needs to be helped to prevent it getting worse. Encourage workers toreport any signs and symptoms early before they become too serious, and seek medical help inecessary.

People with WRULDs usually completely recover if the problem is recognised early and treatedappropriately. The approach in most cases is for the affected person to rest their arm/hand toreduce inflammation. Physiotherapy may help. If you find that a task is causing or contributing to aWRULD, you should stop the worker from doing that task.

If a worker has been off work suffering from a WRULD, the timing of their return depends onmedical advice. But it is possible to return before all the symptoms have cleared up totally. Whensomeone returns to work, it is preferable for them to carry out light duties or reduced hours to startwith.

So remember:

things can be done to prevent or minimise WRULDs;


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preventative measures are cost-effective;

you cannot prevent all WRULDs, so early reporting of symptoms, proper treatment andsuitable rehabilitation is essential.

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2.0 Display screen equipment

According to the Health and Safety (Display Screen Equipment) Regulations 1992, AnnexB, the main ill-health effects associated with using display screen equipment are:

Upper Limb Pains and Discomfort

A range of conditions of the arm, hand and shoulder areas linked to work activities are nowdescribed as work related upper limb disorders. These range from temporary fatigue orsoreness in the limb to chronic soft tissue disorders like peritendinitis or carpal tunnelsyndrome. Some keyboard operators have suffered from occupational cramp.

The contribution to the onset of any disorder of individual risk factors is not clear. It is likelythat a combination of factors is concerned. Prolonged static posture of the back, neck andhead are known to cause musculoskeletal problems. Awkward positioning of the hands andwrist are further likely factors. Outbreaks of soft tissue disorders among keyboard workershave often been associated with high workloads combined with tight deadlines. This varietyof factors contributing to display screen work risk requires a risk reduction strategy whichembraces proper equipment, furniture, training, job design and work planning.

Eye and Eyesight Effects

Medical evidence shows that using display screen equipment is not associated with damageto eyes or eyesight; nor does it make existing defects worse. But some workers mayexperience temporary visual fatigue, leading to a range of symptoms such as impairedvisual performance, red or sore eyes and headaches, or adoption of awkward posture whichcan cause further discomfort to limbs. These may be caused by:

staying in the same position and concentrating for a long time;

poor positioning of the display screen equipment;

poor legibility of the screen or source documents;

poor lighting, including glare and reflections;

a drifting, flickering or jittering image on the screen.

Like other visually-demanding tasks, VDU work does not cause eye damage but it maymake workers with pre-existing vision defects more aware of them. Such uncorrecteddefects can work with display screen more tiring or stressful than would otherwise be thecase.

Fatigue and Stress


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Many symptoms described by display screen workers reflect stresses arising from their taskThey may be secondary to upper limb or visual problems but they are more likely to becaused by poor job design or work organisation, particularly lack of sufficient control of thework by the user, under-utilisation of skills, high-speed repetitive working or social isolation.

All these have been linked with stress in display screen work, although clearly they are notunique to it; but attributing individual symptoms to particular aspects of a job or workplacecan be difficult.

The risks of display screen workers experiencing physical fatigue and stress can beminimised, however, by following good practice techniques such as - careful design,selection and disposition of display screen equipment, good design of the user's workplace,environment and task, training, consultation and involvement of the user.

The regulations also refers to other risks to ill-health:

Epilepsy

Display screen equipment has not been known to induce epileptic seizures. People whosuffer from very rare (1 in 10 000 population) photosensitive epilepsy who react adversely toflickering lights and patterns also find they can safely work with display screens. People with

epilepsy who are concerned about display screen work can seek further advice from localoffices of the Employment Medical Advisory Service.

Facial dermatitis

Some display screen users have reported facial skin complaints such as occasional itchingor reddened skin on the face and or neck. These complaints are relatively rare and thelimited evidence available suggests they may be associated with environmental factors,such as low relative humidity or static electricity near the display screen equipment.

Electro-magnetic radiationAnxiety about radiation emissions from display screen equipment and possible effects onpregnant women has been widespread. However, there is substantial evidence that theseconcerns are unfounded. The Health and Safety Executive has consulted the NationaRadiological Protection Board, which has the statutory function of providing information andadvice on all radiation matters to Government Departments, and the advice is summarizedas:

The levels of ionising and non-ionising electromagnetic radiation which are likely to begenerated by display screen equipment are well below those set out in internationalrecommendations for limiting risk to human health created by such emissions and the

National Radiological Protection Board does not consider such levels to pose a significantrisk to health. No special protective measures are therefore needed to protect the health ofpeople from this radiation.

Effects on pregnant women

There has been considerable public concern about reports of higher levels of miscarriageand birth defects among some groups of visual display unit (VDU) workers in particular, due


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to electromagnetic radiation. Many scientific studies have been carried out, but taken as awhole their results do not show any link between miscarriages or birth defects and workingwith VDUs.

In light of the scientific evidence, pregnant women do not need to stop work with VDUs.However, to avoid problems caused by stress and anxiety, women who are pregnant orplanning children and worried about their concerns should be given the opportunity todiscuss their concerns with someone adequately informed of current authoritative scientificinformation and advice.

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2.0.1Jobs Giving Rise to Risk of Injury

Musculoskeletal disorders can be developed from a number of different types of work situations.They tend, however, to be most closely related with those tasks that involve one or more of thefollowing:

Prolonged periods of sitting, especially if posture is poor and there are limited opportunitiesfor breaks;

Prolonged periods of standing, such as on a production line where there may be limitedopportunity to move around;

Repetitive movementsover prolonged periods such as some manual assembly work, workingat conveyors, bricklaying etc;

Repeated use of forceand especially where that force is applied in an awkward position;

Manual handlingof loads, especially if the work is repetitious or prolonged, which will induce

muscle fatigue. Manual handling of people is a major issue amongst healthcare workers,who require training in specific techniques to move people and especially bariatric patients;

Work in restricted work spaceswhere it is necessary to adopt an awkward posture in order toget at the item being workedon or with e.g. working under a vehicle in a garage inspectionpit.

As well as the nature of the task itself, certain environmental factors such as cold workplaces wilexacerbate the problem, since muscles will not be as supple in cold weather as they mightotherwise be in warmer environments.

The example of the production/assembly line is useful in helping to show how a number of theabove factors may conspire to increase the overall risk to the worker. Assembling items from small

components can cause a number of different health effects over the medium to longer term. Theseinclude:

Back pain, especially in the lower back, caused by prolonged periods of standing in a staticposition, often on hard surfaces such as concrete floors with little or no cushioning effect. Thepotential for back pain can be made worse by poor task layout that requires the worker to reachover, say, a conveyor, or to twist or stoop to find component parts ;


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Work-Related Upper Limb Disorders (WRULDs), which is a generic term for any type of upperlimb disorder affecting hands, wrists, forearms, shoulders and upper back and can be caused inmuch the same way as back problems and especially by repetitive movements;

Eye strain from having to focus on small component parts, especially where parts need to becarefully aligned in order to fit together;

Fatigue and stress, which is related to a lack of breaks or a high work rate (material on stresscausation has been covered in element IB8).

X-Ray showing poor posture while working at a desktop computer

Another example of a type of work that is being increasingly linked to the development and onset ofMSDs is work with display screen equipment, and especially laptop computers. A person joiningthe workforce today, say at age 18, has probably already had a number of years of exposure to theuse of computers while at school and college. The rise of computer-based gaming will have addedsignificantly to this exposure in many cases, meaning that many young workers have already begunto develop problems even before starting work. During that time, while the body is still developing,they may well have fallen into bad habits with regard to use and posture since it is almost certainthat they will not have had specific training nor would their usage have been assessed. That sameperson may now enter a line of work where, unless there is a radical change in technology, theymight continue to use computers for the next 50 years. If that is the case then one can easily seethat the next generation is storing up a host of problems, which include:

WRULDsfrom prolonged use of small keyboards and pointing devices, often in less than idealcircumstances with regard to location and posture;

Eye strainresulting from excessive screen time which can eventually lead to more serious eyeproblems;


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Back paincaused by adopting a poor posture and working on a laptop in that position for anextended period;

Fatigue and stressassociated with the type of work being conducted, which is linked to othertopics on this course such as dealing with aggressive customers.

3.0 Assessing and controlling risks from repetitive activities,

manual handling and poor postureFactors for consideration when assessing risks

The following factors need to be considered as appropriate whenever conducting an assessment ofthe risks associated with repetitive physical activities, manual handling and poor posture:

The Task

When assessing the potential for development of MSDs, the first thing that should be considered isthe nature of the task itself. For example, the assessor may wish to consider whether the taskinvolves:

Long carrying distances;Excessive upward reaching, or stooping;

A requirement to reach into or over something;

Significant repetition;

A need to twist from one position to another

Lifting loads from above shoulder height or from below knee height;

Availability of rest breaks

The assessor should also consider the amount of forcenecessary to complete the task e.g. using

manual hand tools such as a screwdriver may require considerably more force that using a poweredversion.

The Load

Features of the load also need to be analysed. The obvious thing to consider is the weight of theload, but just because a load may not weigh much does not always mean that it is going to be freeof risk when lifted. Factors to consider include:

Sharp edges;

Hot (e.g. boiling water) or cold (e.g. cryogenic) loads;

Availability of hand holds;

Bulky or unwieldy;

Difficult to grasp;

Whether the load has an uneven centre of gravity;

Unstable loads e.g. liquids

Live loads such as animals.


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The Environment

The task will be conducted in a workplace, which may have aspects that will need to be consideredwhen planning how to move loads around and which may impose certain constraints on theworkforce. Factors for consideration here include:

Restrictions on available space e.g. moving loads from inside cupboards;

Condition of the floor surfaceslippery or uneven;

Unmarked changes in level or obstructions that can create trip hazards;

Lighting levels are they adequate? Will eyes take a few seconds to adjust when comingindoors from bright sunshine?;

Temperature and humidity, which may work to make it more difficult to grip an object due tosweating.

Individual Capability

The final factor for consideration is the person who will be doing the work. Considerations include:

Whether the task calls for unusual ability such as strength, or adoption of a particular technique;

Pre-existing injuries and/or ill-health conditionsDegree of training and experience;

Clothing being wornloose clothing is generally better as it allows the worker to adopt a betterposture;

Factors such as age, general fitness and height;

Whether the task poses a particular risk to certain groups such as pregnant workers.

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3.1 Methods of assessing risks

Perhaps the simplest way to assess risks associated with tasks involving repetitive physical activity,manual handling and poor posture is to observewhat is being done and make notes on aspects ofthe task, the load, the working environment etc that appear to create risks.

The assessor will first watch the task to get an idea of how it is done and exactly what is involvedThe job can then be broken down into stages and the assessor will then watch it a second time,using a checklist covering factors like those identified above, to record their findings. The workerscan be asked about the task and their input can be sought with regard to which are the most

problematic aspects of it and what they feel can usefully be done to mitigate the risks.

In this way, the assessor, in co-operation with the workforce, can come up with control measuresthat will help in reducing the risk.

Observation is at the heart of any assessment. Over the last few years, however, a number oftechniques have been developed that aid the assessor in examining the task in varying degrees ofdetail. Most of these approaches offer a form of numerical scoring system, which is useful forcomparing risks between activities and helps with the prioritisation of resources.


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Tools of this type that are commonly in use include:

The HSE Manual Handling Assessment Tool (MAC);

HSE ART Tool;

NIOSH Manual Material Handling (MMH) Checklist;

The Rapid Upper Limb Assessment (RULA); and

The Quick Exposure Checklist (QEC)

The HSE Manual Handling Assessment Tool (MAC) (Source: HSE)

The MAC Tool is detailed on the HSE Website and is freely available to users. The bulk of thedescription that follows is taken from the HSE website.

The MAC tool was developed to help the user identify high risk workplace manual handlingactivities. It can be used to assess the risks posed by lifting, carrying and team manual handlingactivities. It is designed to help the assessor to understand, interpret and categorise the level of riskof the various known risk factors associated with manual handling activities. The MAC incorporatesa numerical and a colour coding score system to highlight high risk manual handling tasks.

Three types of manual handling operation can be assessed:Single lifting operations;

Single carrying operations;

Team handling operations

Each operation is divided into different risk factors and presented as a flowchart, which is used toguide the assessor through the process. A similar methodology is used for the assessment of eachof the three types of manual handling operation identified above. Therefore, for the purposes of thisdescription, only the first, Single lifting operations will be outlined.

The risk factors that are assessed are:

ALoad weight/frequency

BHand distance from the lower back

CVertical lift region

DTrunk twisting/sideways bending

EPostural constraints

FGrip on the load

GFloor surface

HOther environmental factors

To complete the assessment, the assessor will first familiarise themselves with the task by spendingsome time observing it. Employees and safety representatives should be consulted at this stageand throughout the assessment process. The task can be videoed in order to allow it to be studiedmore closely away from the workplace is necessary.

The appropriate type of assessment (lifting, carrying or team handling) is then selected and thecorresponding assessment guide and flow chart are then followed to determine the level of risk foreach risk factor. The levels of risk are classified as in the table below (Source: HSE).


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An example of one of the risk factors and the range of scores that might be allocated is given below:

Example Risk Factor

Source INDG383, Manual Handling Assessment Charts, HSE, 2003

The assessor considers what they are observing and scores the task as they see it. Thus, if the loadis to be lifted from a position below the knee, a score of 1 will be given, representing an Amber riskfactor.

As the assessor works through the flow chart (see example below), the colour bands andcorresponding scores are entered onto a score sheet. The total score is added once the end of theflow chart is reached. This helps the assessor to then prioritise actions.

The MAC flow diagram for this type of operation is shown below.


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MAC Flow Chart for a Single Lift Operation

Source INDG383, Manual Handling Assessment Charts, HSE, 2003

HSE Assessment of Repetitive Tasks (ART) Tool

This tool was developed to assist in the assessment of tasks that require the repetitive movement ofthe upper limbs. It examines some of the common risk factors in repetitive work that contribute tothe development of upper limb disorders.

ART is suited for tasks that involve actions of the upper limbs that repeat every few minutes or evenmore frequently and which occur for at least 1-2 hours per day or shift. Such tasks are typicallyfound in assembly, production, processing, packaging, packing and sorting work as well as work

involving regular use of hand tools. The ART tool is not intended for display screen equipment(DSE) assessments.

To complete the assessment, the task is observed and workers consulted. A task description form isthen used to describe the repetitive task to be assessed. The assessor then decides whether toassess just one arm (the one predominately involved in the task) or both. The assessment flowchartis used to guide the assessor through the assessment process.

The assessment is split into four stages:


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Stage A: Frequency and repetition of movements;Stage B: Force;Stage C: Awkward postures; andStage D: Additional factors.

For each stage, the assessor follows the flow chart to determine the level of risk, which arecategorised according to a traffic light systemGreen, Amber and Red.

An example of on risk factor is given below:

Example of one risk factor considered by the ART Tool.

Source: HSE, INDG438

Scores are allocated for each of the risk factors, which are then totalled to give an overall risk score.This figure is then multiplied by a Duration multiplier according to the length of time spent doing thetask in question. This Duration multiplier is found a table at Stage D (D4) and ranges from 0.5where less than 2 hours per day is spent doing the task, up to 1.5 where the task is done for morethan 8 hours.

Once the exposure score has been calculated (Task score x Duration multiplier), the score isinterpreted by reference to the table below.


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ART Tool - Interpretation of exposure scores.

Source: HSE, INDG438

NIOSH Manual Material Handling Checklist (MMH)This is published is the USA by the National Institute of Occupational Safety and Health (NIOSH)The booklet aims to help recognise high risk manual materials handling tasks and to chooseeffective options for reducing the associated risks. Approaches covered include:

Eliminating lifting and using trollies etc;

Using lift-assist devices like scissor lift tables or load levellers;

Using more sophisticated equipment like powered stackers, hoists, cranes or vacuum assistdevices;

Guiding the choice of equipment by analysing and redesigning workstations and workflow.

The booklet features a great many photographs to show common manual handling problems andsolutions, including kinetic lifting techniques. The checklist itself is not designed to be acomprehensive risk assessment technique but rather as a tool to quickly identify potential problem

jobs. Further risk factors not considered in the checklist may also need to be accounted for by theuse of other techniques. The checklist itself may be found at Appendix B of the document.

Rapid Upper Limb Assessment (RULA)

Rapid Upper Limb Assessment (RULA) is a survey method developed for use in ergonomicinvestigations of workplaces where work related upper limb disorders are reported. RULA is ascreening tool that assesses biomechanical and postural loading on the whole body with particularattention to the neck, trunk and upper limbs.

A RULA assessment gives a quick and systematic assessment of the postural risks to workers. Thescoring generates an action list which indicates the level of intervention required to reduce the risksof injury due to physical loading on the operator. RULA is intended to be used as part of a broaderergonomic study.

The assessment can be completed online. The first step is to observe the task and select theposture for assessment. Depending upon the type of study, selection may be made of the longestheld posture or what appears to be the worst posture(s) adopted.


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Step 2 involves scoring and recording the posture. The assessor decides whether the left, right orboth upper arms are to be assessed. The software is then used to score the posture by asking theassessor to select the image that most closely reflects the working position. A score is automaticallyapplied for each choice. Once this process is complete the scores are automatically calculated.

Left: A sample from a RULA for the Upper Right Arm

In the third and final step, the total score is compared to the Action Level List which provides aguide for further action.

Quick Exposure Check

The Quick Exposure Check (QEC) is similar in many respects to the ART Tool described aboveQEC allows safety practitioners to assess exposure and change in exposure to the main risk factorsfor MSDs. By assessing exposure as opposed to risk, the effectiveness of workplace interventionscan be evaluated without waiting for changes in the prevalence of WMSDs to become evident.

The main benefits of the Quick Exposure Check (QEC) are that it:

Is user-friendly

Is straightforward to use;

Helps persuade organisations to make ergonomic changes

Is compatible with HSE risk assessment methods

Involves both the practitioner and the worker in the assessment, thereby providing a betterunderstanding of working practices.

QEC assesses the exposure of the four body areas at greatest risk to the most important riskfactors for MSDs. It encourages consideration of changes to workstations, tools, equipment andworking methods to eliminate, or at least minimise, levels of exposure.

A full description of the tool may be found in an HSE paper athttp://www.hse.gov.uk/research/rrpdf/rr211.pdf

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3.2 Practical Control Measures

The assessment techniques outlined above lead to consideration of control measures to eliminateor reduce the risks associated with repetitive physical activities, manual handling and poor postureTypically, control of such risks can be achieved by making alterations to:

The way the task is done;

The tools, equipment and machinery used;

The workplace environment.

In some cases, tasks giving rise to a risk of MSDs can be eliminated in whole or in part. If, however,

the task cannot be eliminated then there are still many options available for the reduction of risks.An overview of these options is given below.

Elimination

The obvious method of elimination is simply to not do the job at all. However, this may not be apracticable solution, although it may be possible to do the job in another way. For example, it maybe possible to eliminate manual handling activities by installing automation such as conveyorsystems or by mechanising the whole or part of the task e.g. through the use of fork lift trucksOther options for mechanisation include use of hoists, cranes, pallet trucks, lifting tables etc


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Above: Mechanisation - Use of a scissor Above: Mechanisation - Use of a turntable

lift table

Alternative work methods/J ob design

One alternative is to automate or mechanise the process as outlined above. Use of some aids suchas sack trolleys is not strictly speaking elimination since some manual effort is still needed.

Changes can be made to work routines such that individuals do not spend too long doing aparticular task such as working on a supermarket checkout, which requires some seated handlingand twisting and which affords limited opportunity to move around. In that case, job rotation to othertasks is commonplace.

Allowing workers some control over the pace of the task may also help to reduce the risks.

For large loads, which may not only be heavy but are also bulky, the introduction of team handlingwill help to share the load. It may even be possible to break the load down into smaller parts.

Ergonomic design

The task and workstation can be evaluated and ergonomic principles can then be applied to helpmake the job more efficient and less tiring.

Ergonomics is the science of fitting the job to the person. Such an approach looks at the job as awhole and takes account of a number of factors including the nature of the task, the load and theworking environment as well as individual capability. In an assembly task for example, anergonomic approach will seek to ensure that all frequently used parts and tools are within easyreach and that the worker does not need to bend or twist to find them. Tools will be as light aspossible and will have grips that allow the worker to adopt a neutral position rather than placingstress on the wrists.

Ergonomics can be applied to tools and to workstations, such as with Display Screen Equipmentworkstations where much work has been done on designing computers and peripherals such thatrisks of MSDs are reduced. The ergonomic approach will also ensure that workstations can beadjusted to suit the individual workers needs.

Work Routine

This can be thought about in order to allow the worker sufficient rest and recovery breaks. Jobrotation is one method for achieving this. Another example would be to building different tasks intoan office workers role so that they do not sit at a computer for the entire day but instead also haveto get up to do tasks such as filing or to retrieve printing or copying.

Eye and Eyesight testing

This is commonly applied to those who use display screen equipment as an integral part of their jobEye strain can develop over time with heavy use of DSE and so regular testing helps to give anearly warning of deterioration in the workers sight so that modifications can then be made to theirworkstation or work routine.


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Training and Information

Any employee who may be at risk of developing a MSD should be given information on the types ofharm that might arise and the signs and symptoms thereof, as well as use of the control measuresto help avoid such conditions. For example:

Display screen equipmentusers can be shown exercises that they can do at their desksthat will reduce the impact of working in a fixed position for prolonged periods. They should

also be taught how to adjust screen brightness and contrast and how to adjust their chair andworkstation correctly.

Those engaged in manual handlingactivities need to be shown the correct way of lifting aload and how to properly use any handling aids that may have been provided.

One example of a technique that workers who lift loads as part of their job may be shown is theKinetic lifting method. Other methods are taught for tasks like moving patients, but these areoutside the scope of this course.

The basic kinetic lifting technique begins with the assessment of the load. The worker shouldconsider the size and weight of the load, think about its likely centre of gravity and plan the route heor she intends to take to move the load from A to B.

The worker should, if possible, face the intended direction of travel when lifting. He should bend theknees and use the large leg muscles to lift the load. The back should remain upright and the loadshould be held close to the body with a firm grip. The worker should avoid twisting or jerking theload, but should instead lift smoothly and steadily.

Placing the load down is basically the reverse of picking it up, with the same basic principlesapplying only this time in reverse.

Above:The Kinetic Lifting Technique

Personal Considerations

One consideration in any manual handling assessment is the capability of the individual. Theemployer should therefore ensure that tasks are only given to those people who have the necessary


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ability and physical attributes to perform the lift safely. For example, if a particular technique needsto be used (e.g. patient handling) then only those who have had specific training should be allowedto perform the task. The employer should also consider the needs of more vulnerable workers, suchas those who are pregnant and who may not therefore be able to lift a great deal.

References:

HSE, 2003. Manual Handling Assessment Charts. INDG383

HSE, 2010. Assessment of repetitive tasks of the upper limbs (the ART Tool). INDG438

NIOSH, Ergonomic Guidelines for Manual Material Handling. ttp://www.cdc.gov/niosh/docs/2007-131/pdfs/2007-131.pdf accessed 17 June 2012

http://www.rula.co.uk/index.html accessed 17 June 2012

Quick Exposure Check -http://www.hse.gov.uk/research/rrpdf/rr211.pdfaccessed 17 June 2012
http://www.rula.co.uk/index.htmlhttp://www.rula.co.uk/index.htmlhttp://www.hse.gov.uk/research/rrpdf/rr211.pdfhttp://www.hse.gov.uk/research/rrpdf/rr211.pdfhttp://www.hse.gov.uk/research/rrpdf/rr211.pdfhttp://www.hse.gov.uk/research/rrpdf/rr211.pdfhttp://www.rula.co.uk/index.html

ib9 musculoskeletal risks and control

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