1026 Int Diploma IB9 v2
March 25, 2017 | Author: farhat ali | Category: N/A
Short Description
nebosh diploma...
Description
Element IB9: Musculoskeletal Risks Musculoskeletal and Controls
Element IB9: Musculoskeletal Risks and Controls
© Santia 2012 ® - restricted use only
Page 2 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
© Santia 2012 ® - restricted use only
Page 2 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Contents Introduction The Human Musculoskel Musculoskeletal etal System
Types of Musculoskeletal Injury and Ill-Health Work-Related Upper Limb Disorders Lower Limb Disorders Back Pain Work-Related Causes of Injury and Ill-Healt Ill-Health h Control Measures
Manual Handling General Management Strategy Specic Assessment Tools Reducing the Risk of Injury Changes to the Working Environment
Computer Work
5 6 11 11 13 14 17 19 23 23 31 37 38
Health Problems The Computer Workstation Risk Assessment and Control
44 44 47 48
References
55
© Santia 2012 ® - restricted use only
Page 3 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
© Santia 2012 ® - restricted use only
Page 4 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Introduction This element will: ▪
Outline types, causes and relevant workplace examples of injuries and ill-health conditions associated with repetitive physical activities, manual handling and poor posture; and
▪
Explain the assessment and control of risks from repetitive activities, manual handling and poor posture.
© Santia 2012 ® - restricted use only
Page 5 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
The Human Musculoskeletal System The human musculoskeletal system consists of the skeleton, made up of bones and held together by ligaments. The skeletal muscles of the body are attached to the bones at both ends by their tendons, and when they contract due to the action of nerve impulses, they cause movement to happen. The anatomy and physiology of these structures will be considered in more detail.
The Skeleton The adult skeleton is made up of 206 distinct bones, ranging in size from the largest, the femur (or thigh bone) to the smallest, the stapes in the middle ear. A newborn baby has over 270 bones, some of which fuse together; the skeleton takes 20 years before it is fully developed. The bone marrow is found in the centre of large bones and produces 500 billion blood cells each day. The main central part of the skeleton (the axial skeleton) consists of the skull, rib cage, sternum (breastbone) and vertebral column (spine). Attached to the axial skeleton is the shoulder (pectoral) girdle, with the arms and hands, and the pelvis with the legs and feet. These parts are the appendicular skeleton. The bones of the skeleton articulate with each other at different types of joints. For example the hip joint, where the head of the femur articulates with the pelvis is a ball and socket joint, which allows a wide range of movement. The elbow joint, however is a form of hinge joint as it produces movement in one axis only. Figure 1: The Human Skeleton
© Santia 2012 ® - restricted use only
Page 6 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Ligaments The ligaments are brous structures that connect bones to other bones, usually at a joint. They are strong with a degree of elasticity, and provide vital stability to joints. However, if they are stretched excessively such as when a joint dislocates, or for long periods, they may not return to their original size. This would reduce the stability of the joint. Additionally, sprained ligaments can take a long time to heal. Figure 2: The Ligaments of the Knee Joint
Skeletal Muscles Skeletal muscles are attached to the bones by tendons. They contract under voluntary control to produce movement of the skeleton.
Abdominal Muscles The abdominal muscles support the lower part of the spine. When air is inhaled, the diaphragm moves down and the abdominal muscles contract. The pressure inside the abdomen increases to provide a structural support for the front of the spine, which is not as closely supported by muscles as the back of the spine. Adequate abdominal pressure can reduce the stress on discs by 40%. The ability to develop this ‘pressure-splintage’ depends very much on the condition of the abdominal muscles, which are vital to back care. Thus, people who are obese and women who are in the later stages of pregnancy are more vulnerable to back strain because the effect of the abdominal muscles is reduced.
© Santia 2012 ® - restricted use only
Page 7 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Tendons The tendons are tough bands of brous material that attach the muscles to the bones. The muscle is attached at both ends by tendons; these points are referred to as the origin and insertion of the muscle. Figure 3: The Muscles and Tendons of the Forearm
Nerves The nerves that supply the muscles and other structures of the body form part of the nervous system, which transmits electrical impulses between the brain and the rest of the body. Nerves emerge from the spinal column to the arms, legs, abdomen and thorax. Sensory nerves allow the person to detect feelings of touch, heat, pain, joint position etc, and motor nerves cause muscles to contract when movement is required.
© Santia 2012 ® - restricted use only
Page 8 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
The Spine The spine is made up of 33 small bones, 24 vertebrae which are connected by intervertebral discs (soft jelly-like pads), muscles and ligaments. Each vertebra has two joints (facet joints), which enable them to move with respect to each other - it is this movement that gives the spine its exibility. The natural upright posture of the spine viewed from behind is straight, and from the side a gentle ‘S’ curve. This curved shape is important as it allows for increased strength and gives the ability to absorb compressive forces. Deviations from this curved shape place extra stress upon the spine. The vertebrae are divided into ve groups, the Cervical, Thoracic, Lumbar, Sacral and Coccyges. Figure 4: The Spine
ure 5: The Intervertebral Disc
re 5: The Inter-Vertebral Disc
The Cervical Spine These are the smallest group of vertebrae and support the smallest amount of weight. They cradle the skull and provide movement and rotation due to the shape of the vertebrae and small controlling muscles. Neck injuries are quite common.
© Santia 2012 ® - restricted use only
Page 9 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Thoracic (The Mid Back) These vertebrae support twelve pairs of ribs. The ribs form a cage, which protects organs such as the heart, lungs and liver. The rib cage can move to aid breathing, but due to their protective role, the ribs restrict the movement in this part of the spine and injuries are not common.
Lumbar (The Lower Back) This area is often referred to as the ‘weak link’ in the back and many back injuries occur in this area. The lumbar spine takes about 60% of the total body weight, and the vertebrae provide good movement in this area.
Sacrum The sacrum is made up of ve vertebra that are fused together forming a ‘wedge shape’ which forms part of the pelvis.
Coccyges These groups of bones are very small and are collectively known as the coccyx. There are many theories as to their use, the most common being that they are the evolutionary remnants of a tail. The Inter-Vertebral Disc The inter-vertebral discs have 3 main functions: ▪
To act as a hydraulic shock absorber, cushioning vibration and compression stresses and spreading the load out evenly over the surface of the vertebral bodies;
▪
To form a strong connecting link between vertebrae; and
▪
To allow movement between each vertebrae whilst at the same time, controlling the extent of the movement in conjunction with other ligaments.
The discs are made up of a gel-like centre called the nucleus, surrounded by layers of tough bres, the annulus. The discs are rmly attached to the vertebrae, above and below. When the spine moves, the discs change their shape to absorb the stress. This is particularly important in the lumbar section of the spine, which is subjected to the greatest weight bearing demands. Figure 5: The Inter-Vertebral Disc
© Santia 2012 ® - restricted use only
Page 10 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Types of Musculoskeletal Injury and Ill-Health It is convenient to categorise musculoskeletal injury and ill-health into the following: ▪
Work-related Upper Limb Disorders (WRULDs);
▪
Lower Limb Disorders (LLDs); and
▪
Back pain.
All of the structures of the musculoskeletal system (joints, muscles, tendons etc) can be injured from work-related activities, but the way they are injured and the parts of the body that are injured are determined primarily by the type of activity being carried out, and the specic risk factors it presents.
Work-Related Upper Limb Disorders Links between work activities and upper limb disorders have long been recognised. Early examples of WRULDs include ‘cotton twisters’ wrist’ and ‘telegraphists’ cramp’. In the modern workplace, increasing automation has reduced the incidence of these historical disorders, but has led to similar problems in other activities. A number of musculoskeletal disorders exacerbated by work factors have been identied. Some disorders are clearly dened diseases and others appear as a loose grouping of symptoms that may indicate an underlying problem. There is no universally accepted framework for classifying the range of WRULDs, although the ILO (1996) identied the most common injuries and diseases caused by repetitive or poorly designed work (Table 1).
© Santia 2012 ® - restricted use only
Page 11 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Table 1: Musculoskeletal Injuries and Diseases (ILO) Injury
Symptoms
Typical Causes
Bursitis
Inammation of the bursa (sack-like cavity) between skin and bone, or bone and tendon. Can occur at the knee, elbow or shoulder. Called ‘beat knee’, ‘beat elbow’ or ‘frozen shoulder’ at these locations.
Pain and swelling at the site of the injury.
Kneeling, pressure at the elbow, repetitive shoulder movements.
Carpal tunnel syndrome
Pressure on the nerves which pass through the wrist.
Tingling, pain and numbness in the thumb and ngers, especially at night.
Repetitive work with a bent wrist. Use of vibrating tools. Sometimes follows tenosynovitis (see below).
Cellulitis
Infection of the palm of the hand following repetitive bruising, called ‘beat hand’.
Pain and swelling of the palm.
Use of hand tools eg. hammers and shovels, coupled with abrasion from dust and dirt.
Epicondylitis
Inammation of the area where bone and tendon are jointed. Called ‘tennis elbow’ when it occurs at the elbow.
Pain and swelling at the site of the injury.
Repetitive work, often from strenuous jobs such as joinery, plastering, bricklaying etc.
Ganglion
A cyst at a joint or in a tendon sheath. Usually on the back of the hand or wrist.
Hard, small, round swelling, usually painless.
Repetitive hand movement.
Osteo-arthritis
Damage to the joints, resulting in scarring at the joint and growth of excessive bone.
Stiffness and aching in the joints.
Long term overloading of the joint.
Tenosynovitis
Inammation of tendons and/ or tendon sheaths.
Aching, tenderness, extreme pain, difculty using the hand.
Repetitive movements, often non-strenuous. Can be brought on by sudden increases in workload or by introduction of new processes.
Tension neck or shoulder.
Inammation of neck and shoulder muscles.
Localised pain in the neck and shoulders.
Having to maintain a rigid posture.
Trigger nger
Inammation of tendons and/ or tendon sheaths of the ngers.
Inability to move ngers smoothly with or without pain.
Repetitive movements. Having to grip too long, too tightly or too frequently.
© Santia 2012 ® - restricted use only
Page 12 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
The main sites affected are ngers and hands, wrists, elbows and shoulders. The most notable symptoms are pain, restriction of joint movement and soft tissue swelling. The sense of touch, the ability to grip, and manual dexterity generally may be affected. The onset of symptoms may be gradual, causing adaptation of working practices to avoid further pain, and often leading to further problems. WRULDs may lead to chronic ill-health and permanent disability.
Lower Limb Disorders Studies have suggested that a signicant proportion of work-related musculoskeletal cases affect the lower limb. Lower limb disorders are important because they are likely to have a greater adverse effect on mobility than either back pain or upper limb disorders. As with other musculoskeletal disorders, the problem is often a cumulative one i.e. it builds up over a period of time. The most common activities found to be risk factors for LLDs are: ▪
Kneeling and squatting;
▪
Climbing stairs or ladders;
▪
Heavy lifting.
▪
Walking and standing activities; and
▪
Slip and trip hazards.
Also there is a possible link with ‘jumping from height’ activities such as drivers of large vehicles exiting their cabs. To a lesser extent, personal factors e.g. previous injury and age, and psychosocial factors such as poor work satisfaction and lack of control over work, may also contribute to the risk of LLDs. The most common conditions likely to be linked to these risk factors are osteoarthritis of the hip and knee, bursitis of the knee and meniscus (knee cartilage) damage.
© Santia 2012 ® - restricted use only
Page 13 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Back Pain Discomfort and pain in the spine is a common complaint among many workers, with the lumbar spine and the neck being most commonly affected. There are 4 main causes of back pain: 1.
Degeneration (wear and tear);
2.
Traumatic Injury (acute);
3.
Cumulative Stress; and
4.
Psychological.
Degeneration (Wear and Tear) The normal ageing process produces ‘wear and tear’ in all the weight-bearing joints including the spine. The degree of ‘wear and tear’, however, varies from individual to individual and may be accelerated by other factors. For example, the repeated vibration and shocks on the spine experienced by a lorry driver, or the additional stresses placed upon the spine of an over-weight person.
Traumatic Injury Traumatic injury is caused by sudden, violent stresses applied to the spine. This can result in damage to the muscles, ligaments and, in exceptional cases, damage to the inter-vertebral discs or the vertebrae.
Cumulative Stress This is probably the most common cause of back pain but the least recognised. As the term implies, cumulative stress occurs gradually, often over several years. Poor sitting and standing postures, poorly designed work environments, obesity and poor muscle condition can all result in twinges of back pain. These twinges are an indication that the spine is being subjected to ‘minor stresses’ and an accumulation of these small incidents may lead to a signicant episode of back pain.
Psychological Back pain with no physical cause may occur in cases of hysteria, depression or acute anxiety. It has been shown that stress may be a predisposing factor to the likelihood of back injury through an accident. Chronic back pain sufferers may become depressed and experience exaggerated pain perception.
© Santia 2012 ® - restricted use only
Page 14 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Prolapsed Disc The common term ‘slipped disc’ is misleading as it implies movement of the disc, which does not usually occur. Discs rarely get damaged by a single action but usually through cumulative abuse. Researc h now shows that repeated stresses caused by twisting and stooping actions can cause microscopic tears in the bres of the disc wall (annulus), which may then lead to a weakness. These tears in the annulus gradually crack open allowing part or all of the gel-like centre (nucleus) to ‘prolapse’ or ‘seep out’. This usually occurs at the back of the disc, close to where the spinal nerves emerge from the spinal cord. The bulging nucleus may press on nearby structures such as nerve roots and ligaments, causing symptoms such as numbness, pain and pins and needles. The pressure created by this situation can cause severe pain and can incapacitate an individual for some time. Figure 6: Prolapsed Disc
Annulus
Spinal cord Spinal nerves
Bulging nucleus The discs increase in size further down the spine to accommodate the extra weight they must carry. During movement a disc distorts and its internal pressure changes. The disc pressure is lowest when the spine is horizontal. In this position the upper body weight is removed from the lower discs. In the standing position disc pressure is low due to minimal distortion. However, when the spine is bent or twisted, the internal pressure can be doubled. It is now believed that increased forces placed repeatedly on discs can eventually result in their damage.
© Santia 2012 ® - restricted use only
Page 15 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Figure 7: Spinal Pressure
g k n i c s i d r a b m u l n o d a o L
Position of the body In the seated position the shape of the spine changes and where the body is in a slouched position the pressure inside the lower back discs is increased. Lifting heavy items from the oor from a sitting position can triple the pressure in the lower discs. In the sitting position the powerful leg muscles cannot assist in any lifting operations and therefore, any stresses are focused on the back.
© Santia 2012 ® - restricted use only
Page 16 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Work-Related Causes of Injury and Ill-Health Work related activities that can give rise to musculoskeletal disorders can be divided broadly into repetitive tasks such as light assembly work, bricklaying, computer work etc, and manual handling activities. The repetitive tasks primarily give risk to work-related upper limb disorders (and sometimes to lower limb disorders), while the manual handling activities commonly cause back injuries. However, there is a large degree of overlap between these distinctions; for example, manual handling activities can be very repetitive, and computer work can give risk to back pain as well as upper limb disorders. For convenience, this element will discuss the work-related risk factors and control measures under the headings of: ▪
Work-Related Upper Limb Disorders;
▪
Manual Handling; and
▪
Computer Work.
© Santia 2012 ® - restricted use only
Page 17 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Work-Related Upper Limb Disorders Risk Factors The main risk factors for WRULDs are: ▪
▪
▪
▪
Task-related factors: ▪
repetition – the more a task is repeated, the greater the risk;
▪
working posture/joint posture – if they are awkward and/or held for prolonged periods in a static or xed position;
▪
use of force (such as squeezing a pair of pliers, or pressing controls with thumb or ngers);
▪
handling and gripping objects eg. tools; gloves can increase gripping force required; and
▪
duration – includes the length of time of the task in each shift, plus the number of working days the task is performed.
Environment-related factors: ▪
excessive vibration forces;
▪
cold temperatures; and
▪
poor lighting.
Organisational factors ▪
high workloads and tight deadlines; and
▪
lack of control over the work.
Worker related factors: ▪
new employees who may need time to acquire skills/rate of work;
▪
individuals with differences in competence and skills;
▪
workers of varying body sizes, ie height, reach; this can lead to adopting poor postures when working at shared workstations;
▪
vulnerable groups, eg younger workers and new or expectant mothers; and
▪
workers with particular health conditions or disabilities.
It should be noted that these risk factors are cumulative; for example, a task carried out in an awkward posture may pose a certain level of risk, but this will be increased if the task is also carried out repeatedly.
© Santia 2012 ® - restricted use only
Page 18 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Control Measures Effective control of WRULDs is delivered through a process of risk assessment and risk management. A combination of good work design and organisational approaches will facilitate the delivery of effective controls.
Work Design Work design approaches focus on reduction of force and repetitive movements, and postural changes.
Reduction of Force Levels Examples of approaches to reduce undesirable exertion of force include: ▪
Reducing the force required by keeping cutting edges sharp;
▪
Ensuring equipment is generally well maintained;
▪
Using powered equipment rather than manual effort;
▪
Using clamps to hold work pieces;
▪
Spreading the force required e.g. designing controls for a power grip rather than a pinch grip;
▪
Gaining better mechanical advantage e.g. longer handled tools increase leverage;
▪
Ensuring that hand protection provided does not exacerbate the problem; and
▪
Ensuring staff are properly trained and competent.
Reduction of Highly Repetitive Movements Generally, approaches rely on task analysis techniques (see later section on Specic Assessment Methods) to identify movements of concern, culminating in control through the restructuring of work methods to reduce repetitive elements in work cycles and limiting the duration of continuous work. Job enlargement and job enrichment approaches provide employees with a larger range and a more varied range of tasks to perform.
Mechanisation and Automation Specialised tools with ratchets or power drivers can be used to reduce repetition. In extreme cases automation may be the most effective option though the expense and technical difculties will have a bearing on its practicability.
Reduction of Machine Pace ‘Self-paced’ systems return control to the operator and may improve stress and fatigue related problems.
© Santia 2012 ® - restricted use only
Page 19 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Postural Changes Postural problems can be designed out in a number of ways: ▪
Redesigning or modifying the process;
▪
Changing the operators’ position relative to the process;
▪
Modifying tools or equipment (eg. bending a tool handle rather than the wrist); and
▪
Moving the part rather than the hand, thus keeping the wrist straight.
Organisational Approaches Organisational approaches look to ensure that the correct individual is ‘tted’ to the correct task. Key issues include personnel selection, training and managing job rotation strategies.
Personnel Selection Issues such as general physical tness, strength, stamina, agility and dexterity may all need to be considered in relation to a specic task or tasks. Age, gender, size, height, disability or previous related injuries or illness may all preclude an employee from undertaking a particular task. To date, attempts at developing a health screening test to predict susceptibility to WRULDs have been unsuccessful.
Training Staff need to be aware of the potential risks inherent in the tasks they carry out and how they can help to prevent injuries and ill health to themselves. This might include how to adjust or alter their workstation to allow them to adopt a good posture, the importance of regular breaks from a particular posture, and how to report issues of concern or to make further suggestions for improvement.
Job Rotation Many manufacturing processes consist of a number of operations linked in series, or operating in parallel. Although each sub operation may be similar, the variation may be sufcient to make consideration of job rotation worthwhile. Broadening employee skills may afford a number of business benets including increased employee satisfaction, and having plenty of cover in case of sickness or other absence. The time and effort necessary to develop job rotation syst ems may have a short term adverse effects on production, on management and supervisory arrangements, and impact upon performance based incentive schemes.
© Santia 2012 ® - restricted use only
Page 20 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Occupations at Risk Many types of work will involve activities that pose a risk of upper limb disorders. Some examples include: ▪
Assembly work, especially using small components and high levels of repetition;
▪
Checkout operators involving repetitive scanning activities;
▪
Trades such as bricklaying; and
▪
Keyboard operators (see separate section on Computer Work).
Specifc Example – Bricklaying Specic risk factors in a typical bricklayer’s job would include: ▪
The frequency of laying bricks / blocks, dictated by mortar drying time, size / weight of brick / block, length and nature of run (straight, corners, etc), experience of worker;
▪
The length of the shift and possible associated time pressure due to working deadlines;
▪
The awkward postures when building at lower and higher levels of bricks, or when reaching for the supply bricks;
▪
The forces when gripping the bricks themselves, when gripping and operating hand tools, and possible additional forces due to the gloves that need to be worn;
▪
Personal factors such as pre-existing medical conditions; and
▪
The possible cold weather conditions.
Suitable control measures would include: ▪
Ensuring adequate rest breaks and reasonable working deadlines;
▪
Providing working platforms where necessary to avoid or minimise the need to stretch, stoop or reach, and locate the supply bricks close the working area;
▪
Provide ergonomically designed tools for easier gripping and use; and
▪
Provide suitable clothing for the weather, and adequate welfare facilities.
© Santia 2012 ® - restricted use only
Page 21 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Specifc Example – Small Assembly Work Specic risk factors in an assembly worker involving small components would include: ▪
Level of repetition involved, which may be quite high with minimum time allowed for rest breaks;
▪
Demanding productivity targets and/or penalties for not achieving a certain throughput;
▪
Poorly designed workstation layout causing the worker to over-reach, stoop, twist etc; and
▪
Level of precision work involved, which may require gripping and ne manipulation of components.
Suitable control measures include: ▪
Ensuring adequate rest breaks and achievable productivity targets;
▪
Considering a job rotation system on the assembly line;
▪
Ensuring the workstations are ergonomically designed to avoid or minimise over-reaching, stooping or twisting; and
▪
Ensuring an adequate level of lighting and providing additional task lighting if necessary.
Specifc Example – Supermarket Checkout Operator Specic risk factors for a supermarket checkout operator would include: ▪
Level of repetition, often high with little time to recover between customers, especially at busy times;
▪
Possibility of over-reaching and twisting to reach items especially if seated; and
▪
Varying and unpredictable weight of some items, which may also be difcult to grasp.
Suitable control measures include: ▪
Adequate stafng levels on checkouts especially at busy times;
▪
Ensuring adequate rest breaks and job rotation possibilities;
▪
Allowing operator sufcient space to sit or stand and ensuring they are aware of how to minimise postural and upper limb stress eg. by standing for some or all of the time, by sliding items rather than lifting them etc; and
▪
Ensuring that an ergonomic design of the checkout is included in any refurbishment that may take place.
© Santia 2012 ® - restricted use only
Page 22 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Manual Handling Manual handling is dened in UK legislation (implementing European Directive 90/269/EEC) as the: ‘Transporting or supporting of loads by hand or bodily force’, and a load is dened as a ‘Discrete moveable object’. Manual handling will therefore include lifting, lowering, pulling, pushing and carrying of: ▪
Inanimate objects, e.g. bags, parcels, boxes; and
▪
Live objects, e.g. people, animals.
General Management Strategy There is now international acceptance of both the scale of the manual handling problem and methods of prevention. Manual handling training alone has not been successful in reducing the risk. An accepted approach to the management of manual handling risk is provided in the following hierarchy of measures: ▪
Avoid hazardous manual handling where there is a risk of occupational injury, so far as is reasonably practicable, i.e. by eliminating the need to lift loads by automation or mechanisation, e.g. placing products on pallets which can then be lifted with fork-lift trucks;
▪
Assess the risk of any hazardous manual handling tasks that cannot be avoided, so far as is reasonably practicable;
▪
Reduce the risk of injury, so far as is reasonably practicable, by implementing control measures by designing the task to meet the needs of the worker, e.g. eliminating the need to twist or stoop or reach, breaking the load into smaller, weights, etc.; and
▪
Review the assessment.
© Santia 2012 ® - restricted use only
Page 23 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Assessment of Manual Handling Risk It will be necessary to consider what tasks are undertaken to identify those which are high risk, and therefore need to be assessed rst. It is neither practicable nor necessary to conduct an individual assessment of every single movement or operation. Many tasks will be similar and frequently repeated. In these cases a generic risk assessment is likely to be acceptable. In the case of delivery operations for example, it may be sufcient to list the various types of tasks, loads and working environment concerned, and then to propose a review of a selection of them. The assessment should identify the problems likely to arise during the kind of operations that can be foreseen and the measures necessary to deal with them. On a day-to-day basis supervisors may have to make further specic judgements when dealing with manual handling tasks. For example, in a warehouse dealing with sacks of sand, a decisi on may have to be made about how to lift broken sacks to prevent spillage and injury. Employees, health and safety representatives, and safety committees should be encouraged to play a positive part in the assessment process. Consulting the employees and using their own experience of the type of work performed will often provide a valuable source of concerns, comments and suggestions. An individual’s state of health, tness and strength can signicantly affect a person’s ability to safely carry out certain manual handling tasks. Physical capacity also varies with age, typically increasing until the early 20’s and gradually declining from the mid 40’s. Pre-employment medical screening will highlight any existing illhealth. Where it is not reasonably practicable to avoid hazardous manual handling operations at work, a detailed risk assessment should be undertaken. An ergonomic approach is taken. A range of physical factors needs to be considered, which can be categorised under the following headings: ▪
Load;
▪
Individual capability;
▪
Task; and
▪
Environment.
© Santia 2012 ® - restricted use only
Page 24 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Load Is the Load: ▪
Heavy – heavier loads will inevitably place greater stresses on the body.
▪
Bulky/unwieldy – if the load is awkward to handle the risks of injury are increased.
▪
Difcult to grasp –e.g. if they are wet or rounded or without hand grips.
▪
Unstable or its contents liable to shift – movement of the load or its contents will place changing and possibly unexpected stresses on the body.
▪
Hot, sharp or dangerous – these characteristics are likely to affect the grip and may make us hold them away from the body, resulting in an increased risk of injury
Individual Does the Job: ▪
Require unusual strength, height etc. – the task should be suitable for the ‘normal’ working population and not rely on height, strength etc.
▪
Create a hazard to those who are pregnant or have a health problem.
▪
Require special knowledge or training for its safe performance.
© Santia 2012 ® - restricted use only
Page 25 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Task Does the task involve: ▪
Holding the load at a distance from the trunk – this increases the stresses on the lower back;
▪
Twisting the trunk – this should be avoided when lifting or supporting a load and is particularly harmful if carried out when seated;
▪
Stooping – this increases the stress on the lower back, which has to support the weight of the upper body as well as the load;
▪
Reaching upwards – this places higher stresses on the back, shoulders and arms especially if the reaching is prolonged or repetitive;
▪
Excessive lifting or lowering distances – the ideal range for handling a load is around waist height. Lifting or lowering a load outside of this range requires greater physical effort;
▪
Handling whilst seated – many movements from a seated position will inevitably involve a degree of stooping and / or twisting, and the leg muscles do not assist with the movement placing high stresses on the lower back;
▪
Excessive carrying distances – the risk of injury increases if a load is carried more than about 10m even if the load is not difcult to handle itself;
▪
Excessive pushing or pulling of the load – the risk of injury is increased if the movement is jerky or the pushing / pulling is carried out with the hands below knuckle height or above shoulder height;
▪
Repetitive handling – this can pose a risk of injury even when the load is not particularly heavy or awkward;
▪
Insufcient rest or recovery periods – this will result in physical and mental fatigue and is especially problematic with repetitive tasks;
▪
Work rate imposed by a process – this is related to the above point where the worker has no discretion over the speed of the activity; and
▪
Team handling – although used to reduce some risks, team handling can introduce other risks, particularly in relation to good planning and co-ordination of the task.
© Santia 2012 ® - restricted use only
Page 26 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Environment Are there: ▪
Space constraints preventing good posture – such as restricted headroom or obstacles;
▪
Uneven, slippery or unstable oors – increase the risk of slipping or tripping whilst handling loads;
▪
Variations in levels of oors or workstations;
▪
Extremes of temperature or humidity - which cause rapid fatigue, impairment of grip and loss of manual dexterity;
▪
Strong air movements – which will greatly increase the risk of injury when handling large loads; and
▪
Poor lighting conditions – increase the risk of collision or tripping.
Additionally, any special clothing or personal protective equipment that needs to be worn need to be considered so that they do not restrict safe movement and good posture. A detailed assessment of every manual handling operation could be lengthy, time consuming, and in many cases a wasted effort, e.g. lifting a glass of cold water involves no risk. Therefore a ‘risk assessment lter’ can be used to screen out lifting operations with risk that is insignicant.
© Santia 2012 ® - restricted use only
Page 27 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Risk Assessment Filter (UK Guidance to Regulations) Guideline gures are provided for the lifting and lowering of loads (see Figure 4), for pushing and pulling tasks, and for handling tasks when seated. If a workplace manual handling task exceeds the boundaries of the guidelines then a full assessment is required. Figure 8: UK Guidelines for Lifting and Lowering
The guideline lters are not weight limits. They may be exceeded where a more detailed assessment shows it is safe to do so. However, normally the guideline gures should not be exceeded by more than a factor of 2. Each box in the diagram contains a guideline weight for lifting and lowering in that zone, that is probably acceptable for the majority of workers. The diagram enables the assessor to take into account the vertical and horizontal position of the hands as they move the load, the height and the reach of the individual undertaking the task. The guidelines are based on no more than 30 operations an hour (or one lift every 2 minutes) with a maximum carrying distance of 10 metres. They assume the load is lifted or carried symmetrically with both hands in a good working environment. The gures need to be reduced if the task is carried out more frequently, or involves twisting.
© Santia 2012 ® - restricted use only
Page 28 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Guideline gures for pushing and pulling, whether the load is slid, rolled or supported on wheels are as follows: Table 2: Guidelines for Pushing and Pulling Pushing / pulling motion
Equivalent weight (men/women)
Force (men/women)
Starting or stopping a load
20 kg/15kg
About 200/150 Newtons
Keeping the load in motion
10 kg/7kg
About 100/70 Newtons
The above gures assume pulling or pushing over a distance of no more than 20m The pushing and pulling forces can be measured using a spring balance weighing scale. This can be attached to the load (usually with a hook) and pulled. Figure 9: Spring Balance
© Santia 2012 ® - restricted use only
Page 29 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Psychosocial Factors The assessment should include, not only the physical risk factors (task, load, working environment and individual) but also psychosocial factors. Psychosocial factors can affect the worker’s psychological response to their work and workplace conditions (including working relationships with supervisors and colleagues). Examples include tight or excessive workloads, and lack of control over the work and work methods. Psychosocial risk factors can lead to stress and can contribute to the onset of musculoskeletal disorders. Undesirable features of the work organisation which can lead to psychosocial risk factors include: ▪
Workers have little control over their work, work methods and shift patterns.
▪
Workers are unable to make full use of their skills.
▪
Workers are not usually involved in decisions that affect them.
▪
Workers are expected to carry out repetitive, monotonous tasks.
▪
Work is machine or system paced.
▪
Work demands are perceived as excessive.
▪
Payment systems encourage working too quickly or without breaks.
These may be considered as part of each manual handling risk assessment, but may be considered separately as they impact on other health and safety issues as well.
© Santia 2012 ® - restricted use only
Page 30 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Specic Assessment Tools There are a number of tools available to facilitate the assessment of workers’ exposure to musculoskeletal risks in the workplace. Some are detailed in this section.
The Quick Exposure Check (QEC) The Quick Exposure Check (QEC) was developed in the UK to enable health and safety practitioners to undertake assessments of the exposure of workers to work-related musculoskeletal risk factors. The main benets of the QEC are stated as: ▪
It provides health and safety practitioners with a user friendly assessment tool with good validity;
▪
It is straightforward to use;
▪
It helps organisations to make ergonomic changes;
▪
It is compatible with some other widely used risk assessment methods; and
▪
It involves both the practitioner and the worker in the assessment, thereby providing a fuller understanding of working practices.
The QEC comprises a front sheet for recording subject information, a one page assessment form and a scoring sheet. A reference guide is also available to explain the use of the tool.
Using the QEC The assessor initially needs to decide on the task or part task to be assessed and observe it for a while. They then answer the questions provided on the form in accordance with their observations of the task. The questions relate to the observed posture of the four key areas of the body likely to be at risk of musculoskeletal injury – the back, shoulder/neck, the wrist/hand and the neck. The worker carrying out the task then answers a number of questions about their experience of the task, scoring issues including the maximum weight they handle, the time they spend on the task, and how stressful they nd it. The scores from both the observer’s assessment and the worker’s assessment can be used to: ▪
Determine the comparative levels of exposure for each body area; and
▪
Identify where exposures are highest, and consequently prioritise the issues the interventions should address.
The aim of an intervention is, of course, to reduce the exposure scores.
© Santia 2012 ® - restricted use only
Page 31 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
RULA (Rapid Upper Limb Assessment) Tool RULA is a survey method developed for use in ergonomic investigations of workplaces, where work-related upper limb disorders are reported. It is a screening tool that assesses biomechanical and postural loading on the whole body with particular attention to the neck, trunk and upper limbs. In a similar approach to the QEC the assessor observes the worker performing the task and considers the working posture of their neck, trunk and upper limbs. These are recorded on a worksheet and a scoring system is applied. Figure 10: RULA assessment of Right Upper Limb
Right Side: Shoulder is raised
r e p p U m r t A h g i R
Upper arm is
abducted Leaning or supporting the weight of the arm
r e w o L m r t A h g i R
Working across the midline of the body or out to the side
t s i r W t h g i R
Wrist is bent away from midline
t s i w T t s i r W t h g i R
Muscle Use
r o d SELECT ONLY ONE OF THESE: f d n a No resistance less than 2kg intermittent load or force a h o e 2 –10kg intermittent load or force L t h i g d & i s 2 –10kg static load 2-10kg repeated loads or forces 10kg or more intermittent load e R c e or force r o h t 10kg static load 10kg repeated loads or forces Shock or forces with rapid build-up F
Posture is mainly static, e.g. held for longer than 1 minute or repeated more than 4 times per minute
The scores will give an indication of risk level and the urgency of implementing improvements.
© Santia 2012 ® - restricted use only
Page 32 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Table 4: RULA Scoring Action level
RULA score
Interpretation
1
1-2
The person is working in the best posture with no risk of injury from their work posture.
2
3-4
The person is working in a posture that could present some risk of injury from their work posture, and this score most likely is the result of one part of the body being in a deviated and awkward position, so this should be investigated and corrected.
3
5-6
The person is working in a poor posture with a risk of injury from their work posture, and the reasons for this need to be investigated and changed in the near future to prevent an injury.
4
7+
The person is working in the worst posture with an immediate risk of injury from their work posture, and the reasons for this need to be investigated and changed immediately to prevent an injury.
Assessment of Repetitive Tasks (ART) Tool The HSE’s Assessment of Repetitive Tasks (ART) tool is designed to facilitate the assessment of tasks that require repetitive movement of the upper limbs (arms and hands). It assists in assessing some of the common risk factors in repetitive work that contribute to the development of Upper Limb Disorders (ULDs). Repetitive tasks are typically found in assembly, production, processing, packaging, packing and sorting work, as well as work involving regular use of hand tools. ART is not intended for assessments relating to the use of computer workstations. The ART tool uses a numerical score and a trafc light approach to indicate the level of risk for twelve factors. These factors are grouped into four stages: A:
Frequency and repetition of movements
B:
Force
C:
Awkward postures of the neck, back, arm, wrist and hand
D:
Additional factors, including breaks and duration
The factors are presented on a ow chart, which enables the assessor to evaluate and grade the degree of risk. The tool is supported by an assessment guide which provides instruction to help the assessor. There is also a worksheet to record the assessment.
© Santia 2012 ® - restricted use only
Page 33 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Manual Handling Assessment Chart (MAC) Tool The MAC Tool was originally designed to help the UK enforcing agencies to assess manual handling risks in the workplace; however it can be used within organisations to facilitate the assessment of manual handling operations. The MAC uses a numerical score and a trafc light approach to indicate the level of risk, and can be used on three types of manual handling task: ▪
Single lifting operation.
▪
Single carrying operation.
▪
Team handling operation.
Figure 11: MAC Tool
© Santia 2012 ® - restricted use only
Page 34 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
These operations are divided into the different manual handling factors and presented as a ow chart. The ow chart leads the user step-by-step, through each factor of the manual handling operation, enabling them to evaluate and grade the degree of risk. Each operation is supported by an assessment guide or aide memoire. These discuss each factor of the ow chart giving helpful pointers to assist in scoring the task being observed. The HSE website provides video clips of each of the operation types covered by the MAC tool, so that its use can be practised using the video clips. When assessing each risk factor, it is usually necessary to consider the ‘worst case scenario’ in terms of posture, frequency, load weight etc. It should be noted that the MAC is not appropriate for some manual handling operations e.g. those that involve pushing and pulling, and it is not intended to assess risks from workplace upper limb disorders. Additionally, the MAC alone does NOT constitute a full manual handling risk assessment. It does however help to identify certain aspects of a manual handling task that need to be looked at more closely. It may also help in prioritising a programme of necessary manual handling risk assessments.
NIOSH Manual Material Handling (MMH) Checklist The USA National Institute for Occupational Safety and Health (NIOSH) has produced a checklist which is not designed to be a full risk assessment, but rather a tool to quickly identify potential problem jobs. Any ‘No’ responses on the checklist indicate potential problem areas that should be investigated further.
© Santia 2012 ® - restricted use only
Page 35 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Table 5: NIOSH Manual Material Handling (MMH) Checklist 1. Are the weights of loads to be lifted judged acceptable by the workforce?
YES
NO
2. Are materials moved over minimum distances?
YES
NO
3. Is the distance between the object load and the body minimized?
YES
NO
4. Are walking surfaces: ▪
Level?
YES
NO
▪
Wide enough?
YES
NO
▪
Clean and dry?
YES
NO
5. Are objects: ▪
Easy to grasp?
YES
NO
▪
Stable?
YES
NO
▪
Able to be held without slipping?
YES
NO
6. Are there handholds on these objects?
YES
NO
7. When required, do gloves t properly?
YES
NO
8. Is the proper footwear worn?
YES
NO
9. Is there enough room to maneuver?
YES
NO
10. Are mechanical aids used whenever possible?
YES
NO
11. Are working surfaces adjustable to the best handling heights?
YES
NO
12. Does material handling avoid: ▪
Movements below knuckle height and above shoulder height?
YES
NO
▪
Static muscle loading?
YES
NO
▪
Sudden movements during handling?
YES
NO
▪
Twisting at the waist?
YES
NO
▪
Extended reaching?
YES
NO
YES
NO
13. Is help available for heavy or awkward lifts? 14. Are high rates of repetition avoided by: ▪
Job rotation?
YES
NO
▪
Self-pacing?
YES
NO
▪
Sufcient pauses?
YES
NO
15. Are pushing or pulling forces reduced or eliminated?
YES
NO
16. Does the employee have an unobstructed view of handling the task?
YES
NO
17. Is there a preventive maintenance program for equipment?
YES
NO
18. Are workers trained in correct handling and lifting procedures?
YES
NO
© Santia 2012 ® - restricted use only
Page 36 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Reducing the Risk of Injury For unavoidable manual handling operations the employer should take appropriate steps to reduce the risk of injury to employees, from manual handling operations, to the lowest level reasonably practicable. In deciding appropriate steps to reduce the risk of injury, it is usually convenient to again consider the task, the load, the working environment and individual capability. However the extent to which any of these factors can be changed may differ between different types of work. Routine manual handling operations carried out in essentially unchanging circumstances (e.g. manufacturing processes) may lend themselves particularly to improvement of the task and working environment. Manual handling operations carried out in circumstances that change continually (e.g. construction sites) may offer less scope for improvement of the task and working environment. In these situations it may be more appropriate to focus on the loads themselves such as making it easier to handle. Training of the workers will be more important in these cases.
Mechanical Assistance The use of mechanical aids usually involves some element of manual handling but will reduce the forces required and allow more efcient handling techniques. All handling aids must be well maintained, and there should be a recognised procedure for reporting faults and defects.
Organisation of the Work System, Workstations or Task There are a variety of possible changes to the workstation or task that can reduce the risk of injury due to manual handling: ▪
Changing the layout of a work area to reduce the need for carrying loads from one place to another;
▪
Placing large and awkward loads on shelves at or near to waist level;
▪
Avoiding the need to carry out handling tasks while seated;
▪
Positioning workbenches to avoid the need for twisting or stretching from one to the other;
▪
Flexible approaches to pauses and breaks from the task to prevent static postural stress and fatigue;
▪
Job rotation to reduce the risk to each individual of a task carried out frequently; and
▪
Establishing procedures whereby the task is carried out by two or more people working together as a team. It should be noted however that team handling can introduce new hazards, and careful planning and co-ordination between the team members is essential.
Additionally, changes to the overall organisation of the work may eliminate or reduce any psychosocial risk factors identied such as reducing monotonous and repetitive tasks and setting reasonable work rates through realistic targets and deadlines.
© Santia 2012 ® - restricted use only
Page 37 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Changes to the Load The risk associated with manual handling can often be reduced by making relatively straightforward changes to the load itself. Examples include: ▪
Making the load lighter and / or smaller in size, e.g. by purchasing smaller units (although it should be noted that this can increase the frequency of the task);
▪
Making the load easier to grasp, e.g. by placing the load in a rigid container or by the provision of handholds and handles;
▪
Ensuring that loads that are liable to move about during handling (e.g. liquids in containers, sacks of powder) are placed tightly in containers or are handled with slings or similar to secure the load; and
▪
Ensuring that wherever possible, loads are not hot, cold, sharp, etc., and where this is not possible, that appropriate PPE is provided.
Changes to the Working Environment The working environment should be designed, constructed and maintained to maximise available space, minimise unnecessary obstructions and hazards (e.g. closed doors, uneven oors) and where possible ensure that operations can be conducted on the same level. Lighting, temperature and ventilation must be suitable for the task and if the workplace is outside (e.g. construction site) procedures are required to stop manual handling activities under unsuitable weather conditions.
Proper Design of Pushing and Pulling Tasks Approximately two-thirds of push-pull accidents involve objects that were NOT supported on wheels, e.g. furniture. Strategies to eliminate or reduce the risks associated with manually pushing or pulling loads should: ▪
Eliminate the need to push or pull by providing mechanical or other equipment. (E.g. conveyors (powered and non-powered); powered trucks; lift tables; or slides and chutes;
▪
Reduce the force required to push or pull by reducing the size of loads or providing equipment such as wheeled trucks or dollies and conveyors and ensuring the maintenance of equipment and the working environment;
▪
Reduce the distance of the push or pull by relocating storage, and working areas, and improving production process to eliminate unnecessary materials handling steps; and
▪
Optimise pulling and pushing techniques, e.g. replace pull with a push whenever possible; provide variable-height handles with suitable hand grips.
© Santia 2012 ® - restricted use only
Page 38 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Proper Design of Lifting and Lowering Tasks The need to manually lift heavy or bulky objects, and reduce unnecessary bending, twisting and reaching should be eliminated or reduced wherever possible by: optimising material ow through the workplace; providing mechanical equipment such as lift tables, vacuum systems, lift trucks and cranes; and reducing the weight of the load (or conversely increasing the weight so that it can only be lifted or lowered mechanically).
Proper Design of Carrying Tasks Carrying materials that are too heavy or too bulky are important factors associated with musculoskeletal strains and sprains. Wherever possible the need to carry should be eliminated, where this is not possible the weights to be carried should be reduced by design or specication of the load itself or its container. Reducing the bulk of materials to be carried and reducing travel distances are also effective means of reducing risk.
Mechanical Handling Mechanical aids vary from simple, manually operated tools to power assisted trucks and lifting devices. All mechanical aids ‘lighten the load’ and make things more efcient - this can lead to fewer injuries and higher productivity. However, the use of handling aids can create different kinds of risks (vehicle and pedestrians coming into contact with each other, exceeding the Safe Working Load (SWL) of lifting devices / accessories, traps, nips, etc.). Mechanical handling aids include: ▪
Simple tools to improve grip or increase leverage, such as lifting hooks, manhole cover lifters and paving slab handlers;
▪
Trucks and trolleys, e.g. sack trucks, pallet trucks and roll cages; and
▪
Lifting devices, such as a block and tackle improve mechanical advantage when lifting or lowering loads manually. Powered hoists further reduce the amount of manual effort.
© Santia 2012 ® - restricted use only
Page 39 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Information for Employees Where tasks involve a risk of injury, employees should be provided with general information about the risks, precautions, safe systems of work and precise information on the: ▪
Weight of each load; and
▪
Heaviest side of any load whose centre of gravity is not positioned centrally.
Training Training alone is not effective to control risk. However, training programmes should include the following: ▪
How to recognise potentially hazardous loads;
▪
How to deal with unfamiliar loads;
▪
The proper use of handling aids;
▪
The proper use of personal protective equipment, e.g. gloves, safety footwear, etc.;
▪
Features of the working environment that contribute to safe manual handling;
▪
The importance of good housekeeping, e.g. keeping paths clear;
▪
The factors affecting individual capacity; and
▪
Good handling techniques, e.g. kinetic handling.
Although good manual handling technique is no substitute for other risk-reduction steps it forms a valuable addition to other risk reduction methods. To be successful, good handling technique requires training and practice. The content of training in good handling technique should be tailored to particular tasks or situations.
© Santia 2012 ® - restricted use only
Page 40 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Figure 12: Kinetic Handling Technique
1.
Assess the load;
2.
Ensure that the travel route is clear and well lit;
3.
Get as close to the load as possible;
4.
Get a secure grip (wear gloves if necessary);
5.
Position feet apart, one foot at to the oor at the side of the load, the other foot behind, with heel raised;
6.
Keep the back straight - maintain the natural spinal curve by lifting the head;
7.
Bend the knees - lift using the thigh muscles;
8.
Keep the load close to the body – heaviest side to the trunk, avoid jerking, make a smooth movement;
9.
Move the feet – avoid twisting at the waist; and
10. Put down, then adjust – slide to desired position.
© Santia 2012 ® - restricted use only
Page 41 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Occupations at Risk Manual handling is an integral part of most occupations; however the extent that workers carry out manual handling tasks and the risks involved obviously vary depending on the characteris tics of the particular type of work. It would be wrong to assume that manual handling injuries will only happen in workplaces where regular handling of heavy items is carried out. In fact, the handling of small loads (les etc) by ofce workers, often from a seated position, can also pose a signicant risk of injury. Additional and unique risks are also faced by workers handling people or animals as part of their work. Two examples are detailed here for illustration.
Specifc Example – Patient Handling in a Healthcare Setting Although the risk factors relating to the environment and individual will be the same as for any manual handling activity, the tasks being carried out are of a more personal nature. They are likely to include transferring patients from a bed to a chair, or to a commode or toilet, and as such may result in a level of embarrassment and reluctance on the part of the patient. This can affect the level of risk and the choice of technique to use. Additionally, characteristics of the person, as the load, will vary depending on their weight, medical conditions and ability to understand, communicate and co-operate. Unlike inanimate loads, people can help (or hinder) the manual handling operation, and they may feel pain and discomfort when moved. Patients may be connected to fragile medical equipment and can sometimes become violent or agitated, affecting the way they are handled. They may also have to be placed into or recovered from unusual positions, such as on an x-ray table or theatre table. Above all, the patient’s safety and well-being are paramount during the manual handling activity, and care must be taken to ensure that the manoeuvre does not cause any injury to them. The following case study gives an insight into how the manual handling of patients can be assessed and improved. ▪
Nursing staff had to help inrm patients by supporting them to the bathroom and helping them in and out of the bath. The patients could be awkward to handle and heavy, presenting a considerable risk of back injury. There was not enough room to use the ward’s patient hoist. The bath was against the wall, and nurses could not get on either side to assist patients. The nursing staff felt there was not enough space to handle the patients. It was difcult for more than one nurse to help, and for them to get into the right position for lifting.
▪
The staff proposed changes to the bathroom layout to make handling the patients easier. More space was created by replacing partitions with curtains. The patients kept their privacy but it was easier for staff to manoeuvre them. The bath was moved away from the wall, giving room to use the patient hoist, and staff could get to both sides of the bath.
© Santia 2012 ® - restricted use only
Page 42 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Specifc Example – Baggage Handling The manual handling of baggage and cargo onto and off aircraft presents a risk of manual handling injury to the ground handlers involved in these tasks. Particular issue s are the restricted space in the cargo area of the aircraft belly, the weight of the items, the repetition involved and the time pressure to complete the task. Similar risks are also present where baggage is manually handled, for example at security check-points, passenger check-in desks, and in the baggage hall. In relation to the task, therefore, risk factors include: ▪
The need to stoop, twist or reach upwards to move the baggage;
▪
The frequency of the move which depends on the number of items;
▪
The need to move items quickly to meet scheduled departure times; and
▪
The distance that the loads may need to be carried.
In relation to the load, risk factors include: ▪
The variable weights of items;
▪
Bulky and unwieldy luggage such as golf clubs or skis;
▪
The possibility of movement of a bag’s contents because of poor packing; and
▪
The slippery nature of the packaging material used which may prevent the handlers getti ng a good grip on the load.
Environmental factors are likely to be the same as for all manual handling tasks (lighting, temperature, space etc) but may pose increased risk if the handling is happening outside due to the possibility of extreme weather conditions. Individual factors such as the tness, training and experience of the handlers are the same as for all manual handling activities.
© Santia 2012 ® - restricted use only
Page 43 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Computer Work Health Problems Health problems are not always work-related, although they could be affected by computer work. In some cases it may be a sign that the users are not working correctly. The health problems associated with computer work are mainly related to the xed posture and repetition of nger movement: ▪
Upper limb disorders (including pains in the neck, arms, elbows, wrists, hands, ngers);
▪
Spinal discomfort or injury due to the prolonged seated position;
▪
Temporary eyestrain (but not eye or eyesight damage) and headaches; and
▪
Fatigue and stress.
Upper Limb Disorders The causes may not always be obvious and can be a combination of factors, but enough is known about the importance of basic precautions especially good posture and variation of work activity (no posture is healthy if it is held for prolonged periods). In order to accommodate the varying dimensions of different individuals it is necessary to make provision for adjustability in the design of workstations.
Carpal Tunnel Syndrome Figure 13: Carpal Tunnel Syndrome
© Santia 2012 ® - restricted use only
Page 44 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Symptoms of carpal tunnel syndrome include pain, which progresses from a dull ache to an intense pain during movement, numbness and tingling of the hands. These sensations are usually felt in the rst three ngers and the base of the thumb. Tendons in the wrist and hand are surrounded by a sheath containing a lubricating uid. With unaccustomed overuse, the lubricating uid in the tendon sheath may be diminished causing friction, which signals the onset of inammation. Repeated episodes of acute inammation thicken the tendons and can impede movement, establishing a permanent or chronic condition.
Posture - Spinal Stress Poor posture can cause backache and pain in the neck/shoulders, mainly due to sitting incorrectly and working for long periods in an awkward position. Although it may seem easy to sit correctly, it can take time and effort to break old habits. Figure 14: Example of Good Posture
Figure 15: Example of Poor Posture
Adopt a relaxed but not rigid position - change position regularly, but always return to an upright position.
© Santia 2012 ® - restricted use only
Page 45 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Figure 16: Keyboard and Arm Position Ensure that the forearms are about horizontal with the keyboard, as shown in the adjacent photograph. Try to keep the hands in a natural position, do not apply excessive force whilst using the mouse.
Temporary Eyestrain Visual discomfort from computer use may be experienced in a number of ways, s uch as dry, running or burning eyes, blurred sight, drowsiness, headaches, difculties with contact lenses, etc.
Fatigue and Stress It is not uncommon for computer workers to suffer stress symptoms in addition to upper limb or visual problems. Disorders of the skin and digestive system are often associated with stress as are conditions such as anxiety and sleeplessness. Under utilisation of skills, sustained highspeed working and social isolation are all likely to increase stress to an unhealthy level.
© Santia 2012 ® - restricted use only
Page 46 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
The Computer Workstation A computer workstation consists of the following elements: ▪
▪
Equipment: ▪
display screen;
▪
keyboard;
▪
work desk/surface;
▪
work chair; and
▪
accessories eg. document holder, mouse etc.
Environment: ▪
space requirements;
▪
lighting;
▪
reections and glare;
▪
noise;
▪
heat;
▪
radiation; and
▪
humidity.
© Santia 2012 ® - restricted use only
Page 47 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Risk Assessment and Control For all computer users, except perhaps those that only use it for very short periods of time (eg. to pick up e-mails once a week), the employer should carry out a risk assessment in order to ensure that the correct equipment is provided, that the user knows how to set it up correctly and that they do not experience any discomfort or health problem from their computer work. Employers should consider: ▪
The whole workstation including equipment, furniture, and the work environment;
▪
The job being done; and
▪
Any special needs of individual workers (whose views should be sought as part of the assessment).
Where risks are identied, the employer should take steps to reduce them.
© Santia 2012 ® - restricted use only
Page 48 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Minimum Workstation Requirements There are some minimum requirements for computer workstations that employers should provide for their computer users. Maintaining a good posture (no posture is healthy if it is held for prolonged periods) and variation of work activity are important. In order to accommodate the varying dimensions of different individuals it is necessary to make provision for adjustability in the design of workstations. Figure 17: Minimum Requirements for a Computer Workstation
© Santia 2012 ® - restricted use only
Page 49 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Table 3: Computer Workstation Requirements 1
Lighting
Satisfactory for the type of work and visual requirements of the user
2
Contrast/ Glare
Contrast between screen and background
Noise
Ability to hear and be heard at normal speech levels
3
Suitable screen positioning to prevent uncomfortable glare and reections
No distractions 4
Leg Room
See seating posture diagram
5
Window Cover
Window blinds etc. must be provided where natural light causes glare or reections
6
Software
Suitable for the task and easy to use Adaptable to the working pace and knowledge of the user Provides feedback to the user No performance monitoring without the operator’s knowledge Information displayed in a suitable format and at a suitable pace Ergonomically sound
7
Screen
Large enough to enable information to be clearly seen Swivel and tilt easily and freely adjustable Height adjustable Adjustable brightness and contrast
8
Keyboard
Manufactured in accordance with BS EN 29241 Separate from the screen Tiltable Legible gures, contrasted keys
9
Work Surface
Sufcient area to accommodate equipment Anti glare nish
10
Work Chair
Stable and comfortable Height adjustable Able to swivel Height/tilt adjustable backrest
11
Footrest
Provided when the user cannot place their feet at on the ground when the chair is at the correct height
© Santia 2012 ® - restricted use only
Page 50 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Pointing Devices The most common input devices other than the keyboard, are the mouse and the trackball. These can be referred to as ‘pointing devices’ and other types include joysticks, touchpads and touchscreens. The mouse will be the most suitable pointing device in most situations. However an alternative device may be more suitable in some situations or may be preferred by the user. Factors to consider when selecting a pointing device are as follows: The environment in which it will be used: ▪
Adequate space;
▪
Suitable surface; and
▪
Fixed stable surface.
Individual characteristics: ▪
Shape and size of the device;
▪
Suitable for left and/or right handed use; and
▪
Suitable for any physical limitation or condition.
Task characteristics: ▪
Amount of use of the device; and
▪
Speed and accuracy required.
It is important to place the device towards the midline of the user’s body, to avoid the need to stretch the arm out to the side. The upper arm should be relaxed and at the side of the body. The arm may be supported on the chair arm or work surface when using the device. Mouse mats should have a smooth surface and be large enough for the task. They should not have any sharp or pronounced edges. The speed and sensitivity of the device should be set to suit the individual user. Periods of using a pointing device should be interspersed with other activities. Training users in alternative methods can reduce intensive use of the device eg. use of keyboard shortcuts. Users should be aware that it is better to remove their hand from the device when not actually using it to avoid prolonged static postures. Pointing devices will need to be maintained and moving parts cleaned periodically. Users should be provided with relevant training and instruction in the setting up and use of their pointing device.
© Santia 2012 ® - restricted use only
Page 51 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Daily Work Routine of Users Employers must plan the activities of users at work so that their daily work on display screen equipment is periodically interrupted by breaks or changes of activity. Intensive work at a display screen can cause visual discomfort that may in turn lead to problems such as headaches and even mental stress. Intensive keyboard use and static posture are contributory factors in most incidences of work related upper limb disorders. Breaking up long spells of display screen equipment work helps prevent fatigue and may prevent work related upper limb problems. Where possible, employers should include spells of other work, e.g. telephone calls, ling, photocopying etc. in user’s work activities. Otherwise, employers should plan for users to take breaks, away from the screen if possible. Those responsible for organising users’ work could consider: ▪
Varying the tasks to include other duties;
▪
Educating users to stretch and change position periodically;
▪
Ensuring breaks are taken before users are tired, rather than to recover, ie. short frequent breaks rather than fewer longer ones;
▪
Offering individual control over work patterns;
▪
Discouraging users from working intensely for too long; and
▪
Imposing rest breaks if necessary eg. in call centres.
Eye and Eyesight Tests The European Directive 90/270/EEC allows for users in member countries (and those who are to become users) to be entitled to an eye and eyesight test on request. The users’ employer pays for this test. If the test shows that the user needs a corrective appliance specically for their display screen work, the employer has to provide this free of charge. Users are entitled to further tests at appropriate regular intervals after the rst test, and in between if they are having visual difculties, which may be reasonably considered to be caused by their display screen equipment work. If a user’s normal glasses for other work are suitable for display screen work then the employer need not pay for them. Employers do not have to pay for designer frames or lenses. Eye and eyesight testing is not an entitlement for the self-employed.
© Santia 2012 ® - restricted use only
Page 52 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
Provision of Training and Information Employers must provide users with adequate health and safety training in the use of any workstation upon which he or she may be required to work. Where a person is to become a user, the training should be provided before he becomes a user. Training should address six inter-related aspects: ▪
The user’s role in the detection of hazards and risks;
▪
An explanation of the causes of injury and the mechanisms through which the harm occurs;
▪
User initiated actions to bring identied risks under control;
▪
Arrangements for bringing concerns to management attention;
▪
Information on eye tests, time management etc; and
▪
The user’s contribution to the assessment process.
Further training should be provided if the workstation is substantially modied.
Portable Equipment Figure 18: Laptops
The use of portable equipment such as laptops and notebook computers should also be considered if these are being used for prolonged periods. Some aspects of the design of portable items (such as smaller keyboards, integral screen and base, integral mouse) may make it difcult to achieve a comfortable working posture. Additionally, this equipment is used in a wider range of environments which may be poorly suited to its use. As it is not practicable to carry out assessments for all the environments in which portable equipment is used, it may be preferable to provide the users with sufcient information and training in order to make their own risk assessment and to control risks whenever they set up their equipment. This assessment should be recorded, for example, if the equipment is in lengthy or repeated use in the same location.
© Santia 2012 ® - restricted use only
Page 53 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
The employer should also ensure that general risk assessments are carried out relating to the manual handling of the equipment between locations and the possible risk to the user’s personal safety when carrying the equipment. Practical points to consider when selecting a portable computer: ▪
Computer of minimal weight eg. 3kg or less, and minimal accessories;
▪
Screen as large and clear as possible;
▪
Detachable or height-adjustable screen where possible;
▪
Long battery life to minimise the need to carry cables and transformer;
▪
Lightweight carrying case with handle and shoulder straps;
▪
Tilt-adjustable keyboards where possible;
▪
Facilities to sue a docking station, external mouse or keyboard;
▪
Effective friction pads underneath the equipment to prevent it sliding;
▪
Sufcient computer memory and speed to minimise use and reduce stress; and
▪
Integral wrist pad between keyboard and front of casing.
© Santia 2012 ® - restricted use only
Page 54 sc/1026/v2
Element IB9: Musculoskeletal Risks and Controls
References UK Royal College of General Practitioners, NHS Executive (2002) The Back Book (2nd Edition) The Stationary Ofce Mckeow, C & Twiss, M (2004) Workplace ergonomics; a practical guide (2nd Edition) Wigston; Institute of Occupational Safety and Health Services Ltd UK HSE MAC Tool: http://www.hse.gov/uk/mds/mac/ Assessment of Repetitive Tasks of the upper limbs (the ART Tool). Guidance for the health and safety practitioners, consultants, ergonomists and large organisations. UK HSE INDG 438; http://www.hse.gov.uk/pubns/indg438.pdf and http://www.hse.gov.uk/msd/uld/art/index.htm NIOSH Manual Material Handling (MMH) Checklist: http://www.dir.ca.gov/dosh/etools/08-004/tool2.pdf Rapid upper Limb Assessment (RULA): http://www.rula.co.uk
© Santia 2012 ® - restricted use only
Page 55 sc/1026/v2
View more...
Comments
