Strategies to tackle musculoskeletal disorders at work

Introduction

Several strategies can be taken to prevent musculoskeletal disorders (MSDs) that are primarily caused or aggravated by work and the work environment (work-related MSDs). These strategies range from technical and engineering measures, over more organisational approaches, to person-oriented interventions. As set out in the EU legislation, prevention of work-related MSDs should be based on the process of (participatory) risk assessment and should consider the general principles of prevention. Research indicates that an integrated, multidisciplinary and participatory approach is required in order to effectively tackle MSDs at the workplace.

Musculoskeletal disorders

Musculoskeletal disorders (MSDs) are impairments of body structures such as muscles, joints, tendons, ligaments, nerves, bones and the local blood circulation system. MSDs can occur in all parts of the body, although the back, neck, shoulders and upper limbs are the most commonly affected areas. When MSDs are primarily caused or aggravated by work and the work environment, they are called work-related MSDs.

Work-related MSDs are in general not caused by one specific, but by multiple risk factors. These include physical (e.g. manual handling of loads, working in awkward postures, repetitive work and working at high speed, exposure to vibrations) as well as psychosocial (work stress) demands.

Regulatory framework for MSD prevention

The EU Framework Directive of 12 June 1989 (Directive 89/391/EEC) sets out the EU regulatory framework for safety and health at work^[1]. Although it does not directly relate to the prevention of work-related MSDs, this Framework Directive contains basic obligations for employers and workers. It obliges employers to take appropriate preventive measures to make work safer and healthier, and introduces the principle of risk assessment as a key element in OSH prevention. It also stresses a hierarchy of preventive measures to be put in place after having assessed and evaluated the risks. These general prevention principles should also be taken into account when choosing strategies and preventive actions to tackle MSDs at the workplace.

Apart from the Framework Directive, the prevention of work-related MSDs is at EU level covered directly or indirectly by various other Directives: Directive 89/654/EEC on workplace requirements, Directive 89/655/EEC on use of work equipment, Directive 89/656/EEC on use of personal protective equipment, Directive 90/269/EEC on manual handling of loads, Directive 90/270/EEC on display screen equipment, Directive 2002/44/EC on vibration, Directive 2003/88/EC on working time are all so-called daughter directives of the framework directive 89/391/EEC ^[2][3]. These directives have been transposed by each Member State into national legislation.

In addition to these Directives, there exist European Guidelines, European Standards (EN, European Committee for Standardisation) and International Standards (ISO, International Standardisation Organisation) that relate to the prevention of work-related MSDs.

Levels and types of prevention

In order to tackle MSDs at work, several preventive strategies can be taken. Three different levels of prevention can be used to categorise these strategies:^[3][4]

1. primary prevention, includes the risk assessment process, and technical/ergonomic, organisational and person-oriented interventions
2. secondary prevention involves the identification and health monitoring of workers at risks
3. tertiary prevention comprises return-to-work actions.

Risk assessment

The risk assessment process forms the basis for the prevention of MSDs at the workplace. Risk assessment for MSDs can take place at two levels, as a primary or secondary prevention measure^[4].

Ergonomic risk assessment is the systematic examination of all aspects of work, considering and evaluating the work-related and individual exposure of workers to physical and psychosocial risk factors for MSDs. The assessment also examines whether these risk factors can be eliminated and, if not, what preventive measures are, or should be, in place to control the risks. The risk assessment process allows to identify prevention priorities. Risk assessment should, if necessary, be supported by ergonomic experts.

In support of the risk assessment checklists can be used. Examples can be found on the EU-OSHA website ^[5][6][7][8]. Methods for assessing MSDs are usually focussed at assessing the physical workload using parameters such as the posture of the body parts, the force the worker exerts, time sequences etc. ^[9]. Methods that are commonly used include:

• KIM - Key Indicator Methods ^[10][11];
• NIOSH lifting equation, this method is also at the basis of standards EN 1005-2 and ISO 11228 ^{[12] [13][14]}
• MAC - Manual Handling Assessment Chart ^[15];
• ART - Assessment of Repetitive Tasks ^[16];
• RAPP - Risk assessment of pushing and pulling ^[17].
• RULA - Rapid Upper Limb Assessment ^[18], also used in EN 1005-4;
• OCRA – Occupational Repetitive Actions ^[19].

Risk assessment can also be applied as a secondary prevention approach, by identifying workers at risk, ensuring the systematic monitoring of their health and investigate work-related causal factors. This should allow early intervention actions and prevent acute MSDs become chronic.

Technical interventions

Technical interventions at the workplace (also referred to as ergonomic or engineering interventions) aim to reduce the physical workload and thus also decrease the risk for MSDs in workers. These interventions can amongst others focus on the elimination or reduction of risks related to manual handling of loads, working in awkward postures, repetitive work and hand-arm tasks, etc.

The following types of technical interventions can be distinguished:^[3][4]

• Automation or mechanisation: decisions to automate certain work processes, to implement powered or mechanical transportation or handling equipment such as conveyor belts, lift trucks, electric hoists, patient lifting devices, etc.
• Ergonomic workplace (re)design: design and optimisation of the (physical) work environment to enable working in a comfortable posture. Ergonomic design should amongst others take the principles of anthropometry into account. Examples are changes in office lay-out, modification of lighting in offices, the adjustment of working heights, etc.
• Ergonomic work equipment and tools: introduction or redesign of ergonomic work equipment and tools. Examples are ergonomic chairs and alternative keyboards and pointing devices in office settings, ergonomic hand tools, etc.
• Exoskeletons: exoskeletons are wearable devices that enhance or support the he physical capacity of the user. They are assistance systems worn on the body and designed to physically assist workers in performing their tasks, and thus reduce their exposure to associated physical demands. The most common applications are back-support exoskeletons designed to prevent low back pain and upper limb exoskeletons designed to prevent shoulder MSDs. The use of exoskeletons is not yet widespread in workplaces. The implementation of these devices can lead to new risks and shift the physical load to other regions of the body. It also can limit the comfort of the user as well as his freedom of movement. Technical or organisational measures should still be preferred over introducing exoskeletons^[20][21].
• Protective equipment: imposed on a group of workers, such as back belt (lumbar supports), wrist splints, and knee protectors. Research on the use of back belts indicates some strong evidence that these lumbar supports are not effective as a primary prevention measure. However, as a second preventive measure they appear to be more effective^[3][4] but it remains unclear if lumbar supports are more effective than no or other interventions for the treatment of low-back pain^[22].

Even though the positive impact of ergonomic tools and workplace adjustment on the physical workload and worker comfort can be demonstrated clearly, systematic reviews of evidence-based research studies (Randomised Control Trials, RCT) in this field generally fail to reveal a direct and strong relation between these ergonomic measures, as a single intervention, and a reduction of MSDs symptoms^{[3][4][23][24]}. The fact that the evidence-base for workplace interventions is limited might be linked to the fact that this research is rooted in the medical research tradition and focussed on the elimination of disease. Consequently, quality criteria for occupational intervention studies are adopted from medical research and randomized controlled trials (RCT) are the gold standard of occupational MSD intervention research. But, the most critical challenges for implementing an intervention occurs at company level and depend on the support of management, the workers and the processes in place. Furthermore, the impact of these interventions go beyond 'eliminating the disease' and also might improve the production system performance as well as other organisational/psychosocial outcomes. Therefore, other research frameworks might be needed to analyse the effects of ergonomic interventions^[25]. Findings from non-controlled and experimental studies ('grey literature') tend to be more positive in this regard^[4].

Organisational interventions

Organisational interventions encompass a broad range of measures related to the work organisation. Since work-related MSDs are caused not only by physical risk factors but also by psychosocial and organisational work factors^[26], such as high work demands, low decision latitude, low co-worker or supervisor support or an effort–reward imbalance, organisational interventions are not only aimed at reducing the physical load but also at improving the psychosocial work environment. Work organisation refers to the way in which work is designed and performed and includes the distribution of work tasks, job design, work processes, work pace, management style, working time, etc. The psychosocial work environment is the product of an interplay between the working conditions and the perceptions of these conditions by the worker (e.g., intensity of work demands, decision latitude, support from co-workers or supervisors, recognition of worker efforts, emotionally demanding work, cognitive demands, workplace sexual and other harassment) ^[27]. Examples of organisational interventions include changing staffing levels, adapting work cycle frequencies, changes to the frequency/duration of breaks, adapting work tasks, for example by using solutions as job enrichment, job enlargement, or job rotation^[28]. To further improve the psychosocial work environment aspects such as decision latitude, employee voice, job demands, etc. have to be integrated into organisational approaches.

Person-oriented interventions

Two main categories of person-oriented interventions can be distinguished: education and exercises^[4].

Education comprises the classic 'back or neck schools' and other ergonomic-related guidance and training programmes. These types of interventions are focused on raising more awareness among workers and attempting to change their working behaviour.

• Back or neck schools train people in the adoption of good working postures, the use of correct lifting/handling techniques, and strengthening exercises^[2][3].
• There are (in-company) training programmes that give training and guidance on proper working methods and practices with the aim to reduce physical strain in workers. These trainings may focus on manual handling, including training in lifting/handling techniques, or focus on group training and counselling on the topic of office ergonomics.
• Education in the prevention of work-related MSDs can also include the dissemination of written information, for example through brochures or leaflets on ergonomics-related topics.

Physical exercises (physical training), for example encouraged through workplace health promotion programmes, aim to increase the worker's physical capacity and thus reduce the discrepancy between the workload and the capacity of the worker^[3].

There is clear evidence from research that (intensive) physical exercise programmes reduce low back pain occurrence. In particular exercises in muscle strengthening appear to play an important role^[4]. Also in exercise programmes to reduce work-related upper limb disorders show beneficial results ^[29]. The primary preventive effect of educational strategies (back or neck schools and other training programmes) on work-related low back pain and other MSDs is less apparent - if these are used as the only preventive measure^[3][4].

Participatory approach

A participatory approach to ergonomics, also called participatory ergonomics (PE), relies on actively involving the workers in planning and controlling a significant amount of their own work activities, and implementing ergonomic knowledge, procedures and changes with the intention to improve working conditions, safety, productivity, quality and comfort^[30]. There is evidence that PE interventions may reduce work-related MSDs^[31][32].

Although every PE intervention is different (there does not exist 'a best way'), six elements of success for implementing PE interventions in the workplace can be identified:^{[33][34][35][32]}

• ongoing management and worker support;
• genuine worker participation throughout the programme (initial hazard identification, risk analysis, solutions and measures, revision of control measures);
• adequate resources committed to the programme and the use of appropriate tools for identifying and analyzing risks;
• appropriate ergonomics training provided to those involved;
• accompanied by a team bringing together the key persons (workers, supervisors and (internal or external) ergonomic specialist(s)) who understand their responsibilities (problem identification, solution development, and implementation of change) and make decisions in a consultative way;
• good communication between team members, management and team, and between the team and individuals in the workplace;
• training in ergonomic principles as well as team work and problem solving so the team functions well to identify and make necessary changes;
• documentation of proposed and implemented changes, follow-up of the whole programme and adapting based on the lessons learned.

Cost-effectiveness of interventions

Beside the knowledge on the effectiveness of interventions to tackle MSDs at the workplace, information on their financial implications is of great importance for OSH management decision-making in organisations. A systematic review of workplace ergonomic interventions containing economic analyses ^[36] tried to find evidence for the financial merits of investment in ergonomic interventions. Only few (16) published intervention studies that included a cost-benefit analysis were retained. The review concludes that there is strong evidence for financial benefits from MSDs prevention interventions in the manufacturing and warehousing sector (mainly participatory, technical interventions), moderate evidence in the administrative and support services sector (investment in office equipment and ergonomic training for office workers) and health care sector (participatory ergonomics and introduction of mechanical patient lifts), and limited evidence in the transportation sector (training programmes on back injury prevention).

Return-to-work

From a tertiary prevention perspective, actions can be taken to support the reintegration (return-to-work, RTW) of workers being absent from work due to a subacute or chronic MSDs. RTW interventions should be initiated as early as possible (in the clinical stage of rehabilitation). A multidisciplinary and coordinated approach is required and can comprise measures for the evaluation and (ergonomic) adaptation of the work process or workplace, and individual support, training and psychomental education^[2][37][4].

Integrated approach

Findings from several systematic reviews indicate that successful ergonomic approaches are not about single intervention programmes (specific implementation of technical, organisational or training measures). Conversely, there is more evidence for the effectiveness of integrated implementation strategies, comprising a combination of preventive measures (multi-component interventions) ^{[3][4][38][39][40]}. There is for example no clear evidence for the positive impact of preventive measures such as workstation adjustments (technical), rest breaks (organisational), or ergonomic training (behavioural) on work-related MSDs ^[41]. When these specific interventions are on the other hand included in a combined approach, they become more effective. The same holds true for office work, where ergonomic training and guidance in proper adjustments of the workstation and the adoption of good working postures have proven to be effective, especially when good quality and adjustable office equipment and furniture are available ^[34].

The following key features of successful and effective ergonomic programmes can be distinguished ^[34]:

• being supported by an organisational policy;
• making available the appropriate technology to the workers enabling them to perform the work healthy and safely;
• being implemented by means of broad-based and tailored ergonomic trainings (covering more than trainings on how to use properly a tool or technique).

Prevention strategies tackling MSDs should be based on a comprehensive approach and considered as part of a long-term commitment to workers’ safety and the company’s success^[42]. Emphasis is placed on the great importance of a prevention-oriented organizational culture ^[4] since there is increased evidence of the impact of psychosocial risk factors on the development of MSDs.

An integrated preventive approach of MSDs embedded in a strong preventive culture requires^[4][42]:

• a clear management commitment demonstrated by allocating adequate time and resources to MSD prevention activities;
• a proactive organisational strategy to manage the health and safety of the workforce and the willingness of the employer to implement innovative strategies in work organisation and personnel development;
• a strong emphasis on communication and reporting;
• comprehensive training and ergonomic interventions tailored to the needs and easy to integrate into workers' current work practices and the organisation’s procedures;
• the development of leadership qualities of (line) managers;
• a participatory approach enabling active worker engagement in occupational safety and health.

Such an integrated approach also means that MSDs strategies should be part of the main management processes^[42]. Bringing ergonomics and MSDs prevention into an organisations' management system can add to its success ^[43].

Prevention in practice

The ESENER survey looks at how European workplaces manage safety and health risks in practice. The survey is organised by EU-OSHA and is carried out every 5 years. The ESENER 2019 is the third wave of the survey, interviewing over 45,000 establishments employing at least five people across all activity sectors in 33 countries. Based on the results, it can be concluded that most European workplaces take measures to prevent work-related MSDs. Providing lifting equipment is the most widespread measure especially in sectors such as Manufacturing, Construction and Agriculture. Almost every workplace in these sectors provides such equipment (more than 85%) (Figure 1). Organisational interventions such as job rotation or encouraging regular breaks are less widespread. Larger companies more often report that they have taken measures to tackle MSDs than smaller sized companies^[26]. More details can be found in the EU-OSHA report on prevalence, costs and demographics of MSDs or by using the ESENER data visualisation tool.

Source:^[26]

Conclusion

As work-related MSDs arise from multiple risk factors of biomechanical, biobehavioural, psychosocial and organisational nature, an integrated, holistic preventive approach is needed. Preventive strategies need to be taken at three levels: primary prevention with a combined focus on the risk assessment process and implementation of technical, organisational and person-oriented measures; secondary prevention targeting early identification and intervention; and tertiary prevention aiming to stimulate and facilitate the (multidisciplinary) return-to-work process of workers being absent from work due to a MSDs problem. This integrated approach can be successful if it is embedded in a participatory environment and a strong prevention-oriented corporate culture.