Body-mapping tools help spot workplace health risks

It is essential to identify the causes of work-related disorders for advisers to solve the problem. Body mapping is a useful tool, says occupational health and safety practitioner Catherine Tye.

The aim of this article is to demonstrate how body-mapping tools can assist employers, managers, occupational health advisers, safety practitioners, safety representatives and workers to identify potential and actual work-related ill health and injury. Body mapping can help pinpoint where the problems lie. This will often differ from where health and safety professionals assume them to be. Once identified, these problems can then be investigated further and potential solutions trialled to reduce the risk of ill health or injury.

A research project by Corlett and Bishop in 1976 is one of the earliest on body-mapping tools. The researchers used a detailed tool to identify musculoskeletal problems and ergonomic issues in spot-welders. The tool focused on body-part “discomfort” rather than “comfort”. In their original paper they discovered that the phrase “we cannot afford to spend money making the workers comfortable” was not unknown to ergonomists.

The tool measured body posture, discomfort and progression of discomfort over time within the individual’s work in a relatively basic manner. It was then used to make changes and subsequently to review effectiveness and any risk transfer (where change to improve posture in one area creates problems in another).

Changes were made to such things as the operating height and force required for foot-pedal operation. The aim was for the machine to be more suited to the body dimensions, strength and flexibility of the workers, thereby improving posture at the joints.

Simplified versions of the tool have been created by various trade unions and are readily available for free download from the internet, for example the one developed by Usdaw (Usdaw, 2009). The use of such a tool can produce a manageable volume of useful information in a time- and cost-efficient manner. This information, when combined with observation and knowledge of the employee’s job and body postures, enables the employer to identify potential or actual causes of discomfort, pain, bruising or other symptoms that can feed into the risk-assessment process.

Usdaw suggests that prior to using the tool the employer needs to consider certain issues that may affect the results. These include: workers not being honest about their symptoms because they fear for their job; workers feeling that their symptoms are related to getting older or being unfit; workers simply accepting symptoms as “part of the job”; and workers forgetting to consider non-work causes of symptoms.






quotemarksUsdaw suggests that prior to using the tool the employer needs to consider certain issues that may affect the results”


Body-mapping tools can be adapted as required; however, there is usually a chart showing the separate front and back view of a body. Using coloured pens or sticky dots, employees doing a particular type of job are encouraged to mark on the chart where they suffer symptoms while they are working and what they believe is the problem and the cause alongside.

The colour coding can be used to identify different problems, for example, red for aches and pains, blue for cuts and bruises, green for other symptoms such as stomach upset, dermatitis, rhinitis, headache and eyestrain, and black for anything else.

A training session is required to enable workers to discuss linking symptoms to postures and to encourage them to review their working practices and, on return to their workplace, to feed back to one another. From the data collected, significant problems can be identified and then compared against the profiles for similar employees, for example between production lines or shifts or locations.

Analysing the results

Collation of the comments and marks on to one chart by job role may show where clusters are emerging, outlining similar jobs with associated, similar or differing problems. An example would be where there are two identical production lines but different symptom patterns such as workers on one dusty line complaining of nasal irritation, but not on the other. This may indicate a local exhaust ventilation fault.

It is worth reviewing the results asking “why?” and requesting ideas for solutions from the employees. All the findings and evidence are then given to the employer or appropriate person along with suggested causes and solutions and a possible action plan.

The Health and Safety Executive’s guidance “Upper limb disorders in the workplace” (HSE, 2002) suggests that body mapping can be used ad hoc or as an ongoing monitoring tool since individuals may not always identify problems themselves but, when viewed across multiple shifts or sites, problems may come to light that require further investigation.

Body mapping can also be used after changes in working hours, working environment, working postures, introduction of new personal protective equipment (PPE), work equipment or work practices. Used within training courses it enables a more worker-centred approach where links can be suggested between symptoms and working practices and influence behavioural change.






quotemarksWorkers need to listen to their body, which will give hints regarding discomfort so they can take action before symptoms occur”


The tool can also be used retrospectively to identify past exposure and subsequent ill health. In Canada the approach was used to map occupational hazards in an asbestos and insulation factory. It mapped ill-health symptoms in exposed asbestos workers years after the factory closed (Brophy JT and Keith MM, 2004). The researchers said: “The study uncovered a grim pattern of occupational diseases. Following release of the results, coupled with clinically confirmed diagnoses and corroborating evidence of exposure, hundreds of former employees and their families received compensation for occupational diseases that had previously gone unrecognised.”

Conclusion

The key message in this article on body mapping is that workers need to “tune-in” and listen to their body, which will give hints regarding discomfort so they can take action before symptoms occur. They need to take responsibility for their health including moving frequently and meeting hydration, exercise, dietary and sleep needs, and seek guidance for problems early on.

Early pain reporting forms can be provided by employers to do this formally, ensuring appropriate referral and completion of detailed personal risk assessment with the manager and an action plan.

Body mapping and the information contained in this article may appear basic to the professional reader, but OH advisers may have only a few minutes to influence an employee’s working posture and behaviour, which have been years in the making.

In the steel-handling example (case study 1), a few weeks after the programme the occupational health adviser visited an employee for review. When the OH adviser asked him how the aches and pains were, the response was “a lot better since those ladies talked to us and demonstrated about joints and posture”.

If employees share their positive experience with their colleagues and family, a culture change may commence. Never underestimate the ability we have in our role (even as an outside contractor, remote adviser or via a newsletter/poster) to share a message, however simple, and influence change.

Catherine Tye is a freelance, dual-qualified occupational health and safety practitioner with a strong interest in strategic and learning and development solutions for OH, safety and musculoskeletal health issues. 

 






Case study 1 – steel handling


Two 90-minute moving, handling and posture sessions were held, squashed into a small canteen. The first session had 11 workers, while the second had six workers who made steel fencing and barbed wire. Two employees in the first session and four in the afternoon were not fluent English speakers. There was a mixture of new and approximately 30- to 40-year-old machinery.

A short body-mapping exercise was undertaken during the training sessions as well as listing all moving- and handling-related tasks and a quiz to consolidate key information. Questions covered topics such as the definition of manual handling, correct posture and how we can get injured, including cumulative injury. Owing to limited time the group focused on red dots for aches and pains and blue dots for bruising.

What was surprising was the minimal amount of back, neck and feet discomfort, a reminder not to make assumptions. The most concerning fact was the amount of cuts and bruising, particularly to the face. There was also a higher incidence of shoulder and elbow discomfort to the left arm, which is not the usual dominant side.

On discussion it was found that cuts and bruising to the face and hands were caused by impact trauma from the release of metal under tension or “catching” hands on sharp metal. The bruising to legs was from bracing of load or unintentional “catching” of the coils of barbed wire when transferred from machine to pallet. Consequently, alternative types of personal protective equipment (PPE) are being trialled.

Through observation and trial and error during the sessions a change in practice was suggested in that the coil of barbed wire was not left temporarily within 0.5m of employees’ shins. This would also help reduce knee discomfort by eliminating the need to squat or kneel. Advice was given on alternative two-handed methods for gripping the coils to lift and lower, thus making greater use of the body in balance. Some employees were not aware of the risks to the upper limb with a 13kg to 18kg load being swung using the non-dominant arm out of a machine, onto the floor and later onto the pallet with one hand.

The hand discomfort and bruising was due to blunt or inappropriate cutting tools with small or no grips requiring greater force from forearm muscles and pressure on hand and wrist joints to succeed in cutting the wire. A discussion with management highlighted issues and suggested actions.

The following is a list of simple ways in which to share the “work in neutral” posture message with employees, which can be used within OH consultations, toolbox talks, induction or training.

Effects of bending/rotation at the wrists Even slight flexion or extension at the wrist results in an immediate reduction in strength (between 30% and 40%). The forearm muscles are designed for fine work. You can demonstrate this to workers by placing your elbow on a table with your wrist in a neutral position and your hand relaxed so that the fingers curl. Place the index finger of the other hand between the thumb and fingers and grip tightly. Relax. Then flex the wrist and repeat. Relax. Then extend the wrist and repeat. When flexed, extended or rotated the ability to grip diminishes and fatigue sets in quicker when compared to neutral.

Effects of working with your arms above chest level for periods of time While sitting or standing, place one hand in the air and the other hand down by your side. After 10 to 15 seconds, describe how your hands feel then bring them together and compare the colour. The drainage of blood is indicated by the speed of colour change and start of muscle fatigue. This can be hastened by the use of vibrating tools such as drills and nail guns, where the vibration affects the nerve and circulatory response in the upper limb. A common complaint and warning sign can be waking in the early hours with numb arms and/or hands that have to be shaken or flicked to restore circulation. The benefit of this technique is that they have also just learnt part of the first-aid treatment (elevation) for bleeding.

Effects of sitting for long periods at desks, meetings, training courses or while driving Ask the group to look around and describe how people appear in the room, for example if they appear tired or pale, with tense shoulders. Ask how they feel, for example, uncomfortable, dehydrated, lethargic, sleepy, complaining of poor memory and concentration.

Effects of standing for long periods and/or extensive walking Ask the group to stand still. Time how long before they start moving, transferring weight, stand on one foot or lean over.

Effects of stooping and/or twisting of the back and/or neck Ask workers their weight. Then remind them that when leaning forward their back, buttock and leg muscles are fighting against their upper-body weight to prevent tipping forwards, which requires greater muscular strain if these muscles are twisted as well.


 








Case study 2 – library services


The author completed classroom-based manual handling training including body mapping for library workers, including the library floor staff and higher-risk employees such as delivery drivers. The drivers drove long distances and could handle up to 100 crates a day weighing between 10kg and 25kg. They carried out multiple loading and unloading of the van as well as pushing and pulling of sack carts over varying distance and terrain.

The driver profile showed mainly lower-back and shoulder discomfort and was different from other library worker profiles where discomfort in feet, upper limbs and mid-thigh bruising were identified.

Library-based employees spend most of the day on their feet and walk long distances (particularly in bigger libraries) but give little thought to the type and style of footwear they wear for work; few considered paying for chiropody or podiatry services.

Foot pains increased following the implementation of customer self-service machines. This was because there was no longer an opportunity to sit, rest or perch between serving of customers at the counter and so librarians spent more time on their feet.

Any upper-limb discomfort appeared to stem from carrying crates or from poor shelf-stacking practices as this entails holding a stack of books down one arm (with the shoulder externally rotated, elbow locked and wrist bent at an extreme angle) while holding a row of books to the side and inserting a book on a shelf either below knee or above chest height. In one library when asked why they did not use a new trolley provided, the response was “my side hurts when I push that”.

On closer inspection the trolley had two one-directional and two multi-directional wheels and they were trying to manoeuvre the trolley using the one-directional wheels. This shows the importance of managers negotiating the purchase or lease of suitable equipment on a “trial or return basis”.

Equipment should be risk assessed using the HSE guidance on manual handling (HSE, 2004), and workers need to be familiarised with new equipment and follow the instructions.

Bruising to the thighs was considered by the employees to be annoying but they accepted it as part of the job. On discussion, it was discovered to be the result of the introduction of self-service machines and associated storage boxes that required the worker to brace themselves against the box edge to lean in and empty it.

Repeated bruising from repeated trauma or pressure at work is unacceptable and solutions need to be found. A manual “Musculoskeletal interventions: techniques for therapeutic exercise” advises: “If the same muscle is bruised over and over again, small calcium deposits may begin to accumulate in the damaged area either between the muscle fibres in the muscle belly or calcium might form a spur that projects from an underlying bone forming a hard lump” (Voight ML et al, 2006).

Some method of prevention is necessary such as redesigning the equipment to eliminate the cause of the problem, using padding or, as a last resort, personal protective equipment (PPE). Managers were not aware of the thigh bruising or increase in foot pain following the introduction of self-service machines. The implications for the health and safety of workers were not fully considered before implementation.

 

References

Corlett EN and Bishop RP (1976). “A technique for assessing postural discomfort”. Ergonomics, 19 (2), 175-82.

Usdaw. (2009, Nov). Body mapping – telling where it hurts. Retrieved 21 Dec 2010.

HSE. (2002). Upper limb disorders in the workplace HSG60 (rev).

Brophy JT and Keith MM (2004). “Participatory mapping of occupational hazards and disease among asbestos-exposed workers”. International Journal Occupational Environmental Health, 10 (2), 144-153.

HSE. (2004). “Manual Handling Operations Regulations 1992 (as amended) Guidance on Regulations” (3rd ed).

Voight ML, Hoogenboom BJ and Prentice WE (2006). “Musculoskeletal interventions: techniques for therapeutic exercise”. McGraw-Hill Professional.

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