Introduction to musculoskeletal disorders
Isabel L. Nunes, Faculty of Science and Technology, Universidade Nova de Lisboa
- 1 Introduction
- 2 Definition
- 3 Prevalence of MSDs
- 4 Impact of MSDs
- 5 Exposure to work-related risk factors
- 6 Groups at risk
- 7 Types of work related musculoskeletal disorders
- 8 References
- 9 Links for further readings
Work-related musculoskeletal disorders (MSDs) cover a broad range of health problems. These health problems range from discomfort, minor aches and pains, to more serious medical conditions that can lead to permanent disability. Every year millions of European workers are affected by MSDs. The most well-known MSDs are low back pain and work-related upper limb disorders. The first is mainly associated with manual handling while the main risk factors for the latter are associated with task repetition and awkward work postures. Nowadays lower limb work-related MSDs are also been recognized as disorders that may be associated with occupational activity. But MSD's are not only linked to physical risk factors. Also organisational and psychosocial risk factors can lead to work-related MSDs .
Work-related MSDs associated with repetitive and strenuous working conditions continue to represent one of the biggest occupational problems in companies. Despite the variety of efforts to control them, including engineering design changes, organizational modifications and working methods training programs, work-related musculoskeletal disorders account for a huge amount of human suffering and to companies and to healthcare systems .
The term work-related MSDs refers to health problems affecting the muscles, tendons, ligaments, cartilage, the vascular system, nerves or other soft tissues and joints of the musculoskeletal system. They are caused or aggravated primarily by work itself and they can affect the upper limb extremities, the neck and shoulders, the lower back area, and the lower limbs.
Prevalence of MSDs
The main work-related health problem affecting European workers is work-related MSDs. Data from the Sixth European Working Conditions Survey (2015) show that almost half of European workers suffer from MSDs. Within the EU, backache seems to be the most prevalent health problem, closely followed by neck and upper limb problems. 43% of the workers reported backache and 41% muscular pains in shoulders, neck and/or upper/lower limbs. Variability among EU Member States’ self reported backache levels are high, ranging from 79% in Finland to 40% in Hungary 
Source: Panteia based on the European Working Conditions Survey (EWCS) 
Similar findings arise from the Labour Force Survey (2013). 60% of the respondents with work-related health problems identified musculoskeletal problems as their most serious work-related health problem and 15.9% identified stress, depression or anxiety as their most serious health problem. It is important to note that the survey only addresses the most serious problem experienced. Respondents may also suffer from other problems (seen as of lesser importance) so these figures should not be regarded as indicative of the total experiencing such problems at all.
Impact of MSDs
Figure 2 contains information regarding DALYs due to musculoskeletal disorders. DALYs for an illness or health condition are calculated as the sum of the years of life lost due to premature mortality in the population and the years lived with disability (YLD) for people living with the health condition or its consequences. In other words, DALYs indicate the gap between current health status and an ideal situation in which individuals live into old age without disease and disability. The statistics are based on a project carried out by several partners such as the International Labour Organisation (ILO) and EU-OSHA to develop updated worldwide estimates of work-related injuries and illnesses .
Figure 2 depicts the proportion of the main work-related illnesses and DALYs per 100,000 workers in the EU-28. Cancer, reaching 25 %, accounts for the main part of the cost, and musculoskeletal disorders follow at approximately 15 %.
MSDs is a major cause of sick leave. In total 61% of the persons that report a work-related MSD went on sick leave. About 35% reported sick leave for less than one month and 26% reported sick leave for at least one month. This means that about 60% of all short term (< 1 month) and long term (at least 1 month) sickness absence in the EU27 due to work-related health problems can be attributed to musculoskeletal problems (Labour Force Survey 2007, ). The same conclusion can be drawn based on the data from the EWCS 2015. Workers with MSDs tend to be absent from work more often than others. Figure 3 shows the number of days in the past 12 months (data for 2015) that workers were absent from their work because of a health issue. More than half of the workers with MSDs and other health problems were absent from work for at least 1 day, while around 23 % were absent for at least 10 days. For workers with only other health problems and workers with no health problems, these proportions are lower.
Figure 3 - Number of days absent in the past 12 months due to a health problem: distribution of workers, for workers with MSDs and/or other health problems and without health problems, EU-28, 2015
Source: Panteia based on the sixth (2015) wave of the European Working Conditions Survey (EWCS) 
The economic consequences are twofold: for employers, MSDs reduce company efficiency due to loss of productivity; and they increase societal costs, namely worker compensation, medical and administrative costs. In some EU Member States 40% of the costs of workers’ compensation are caused by MSDs, reaching up to 1.6% of the gross domestic product (GDP) of the country itself . According to BAuA (Federal institute for occupational safety and health - Germany), MSDs bring about the highest costs in comparison with all other disease diagnosis groups. It is estimated that EUR 17.2 billion production loss (production loss costs based on labour costs) and EUR 30.4 billion loss of gross value added (loss of labour productivity) arise from diseases of the musculoskeletal system. This represents 0.5 % and 1.0 % of Germany’s gross domestic product (GDP), respectively (data for 2016) .
Most persons with low back pain recover quickly and without residual functional loss, irrespective of treatment. Overall, 60 to 70% recovers by 6 weeks, and 80 to 90% by 12 weeks. Recovery after 12 weeks is slow and uncertain. Although the majority of the persons with low back pain will have recovered after several weeks, recurrence frequently occurs. The recurrence rate ranges from 20% to 44% within one year in the working population. Lifetime recurrence ranges up to 85% . These consequences of low back pain and MSDs in general on organisations and companies explain why MSDs are considered an OSH issue of major concern according to the ESENER survey. In about 80% of the organisations MSDs are considered of moderate to major concern. Only "Accidents" have a higher ranking than MSDs .
It is long recognized that work may adversely affect health. Almost three centuries ago (in 1717) the Italian physician Bernardino Ramazzini, father of occupational medicine acknowledged the relationship between work and certain disorders of the musculoskeletal system due to the performance of sudden and irregular movements and the adoption of awkward postures. Due to this fact some disorders assumed names related with the professions where they mainly occurred. Therefor a variety of terms for MSDs can be found that directly refer to jobs and professions, for instance “carpenter’s elbow”, “seamstress’ wrist” or “bricklayer’s shoulder” .
The causes of work-related MSDs are multifactorial and there are numerous work-related risk factors for the various types of MSDs. Several risk factors including physical and mechanical factors, organisational and psychosocial factors, and individual and personal factors may contribute to the genesis of MSDs. Workers are generally exposed to several factors at the same time and the interaction of these effects are often unknown  .
With regard to physical risk factors, studies have found reasonable evidence for an association between different types of MSDs and the following physical risk factors :
- posture and working in awkward positions;
- heavy physical work;
- repetitive work;
- prolonged computer work.
Data from EWCS show that prevalence of MSDs is associated with working in tiring or painful positions, carrying or moving heavy loads and repetitive hand or arm movements. This applies to all three types of MSDs that are distinguished in the EWCS (back, upper limbs and lower limbs). Also other physical risk factors such as vibrations from hand tools and machinery and low temperature can be associated with MSDs. A comparison between EWCS data from 2005, 2010, and 2015 shows a light decrease of exposure for (most of) these risk factors. Despite this positive trend, the data show that European workers remain exposed to several physical hazards associated with MSDs. For instance, one third of the workers (32%) carry heavy loads at least a quarter of their working time, while almost one in five (20%) are exposed to vibration. As Figure 4 shows 40% of all workers work in tiring or painful postures for at least a quarter of the time, and 61% are exposed to repetitive hand or arm movements .
Figure 4 - Percentage of workers reporting that they are exposed to different physical risk factors at their work at least a quarter of the time, EU-28, 2005, 2010 and 2015
Source: Panteia based on the European Working Conditions Survey (EWCS) 
In comparison with the comprehensive research available regarding physical risk factors, research on the association between MSDs and psychosocial and organisational risks is still limited . Several psychosocial factors at work such as low social support, high job demands and low job control cause psychosocial stress. This stress can lead to several physiological and biochemical reactions that can potentially increase muscle tension and consequently result in MSDs. In addition, specific psychosocial factors (for instance lack of decision-making autonomy or excessive workload) can also increase musculoskeletal load and tissue strain, hence raising the risk of developing MSDs. An EU-OSHA study (2019)  has examined to what extent the prevalence of different types of MSDs can be related to psychosocial risk factors. The results of these analyses indicate that several psychosocial risk factors are associated with an increased likelihood of workers reporting MSDs. The following risk factors are found to be significantly related to MSDs: - anxiety; - overall fatigue; - sleeping problems; - low level of mental well-being; - being subjected to verbal abuse at work.
Groups at risk
Due to high exposure to risk factors MSD are particularly prevalent among workers from the following sectors: agriculture, construction, transport and road safety, and manufacturing, hotels and restaurants, health and social work.
Studies suggest that the impact on the prevalence of MSDs is not related to the industry sector but to the actual content of the job. When controlling for the actual content of the job, no significant differences emerge among industries .
Women have been reported as having a higher incidence of MSDs . However, there is no evidence that gender per se is a significant factor for the development of MSDs. The analysis of MSDs records shows that most disorders can be explained based on job characteristics. Men jobs appear to generate mainly exposure to physical risk factors, while typical women tasks involve a combination of physical factors (e.g. prolonged standing and sitting, forced postures, job involving moving people and repetitive work) and psychosocial factors (e.g. time pressure). For instance, regarding lower limbs the type of job can explain some gender differences in the type and frequency of disorders:
- men in construction are mostly affected by knee problems;
- women are significantly exposed to prolonged standing and walking (e.g. in the retail sector, the hotel and catering sector, cleaning work, education or in health care) reporting more problems in hips, legs and feet. Other possible causes for the higher incidence of MSDs among women are: domestic work; hormonal cycles; pregnancy or use of the contraceptive pill .
The likelihood of reporting MSDs increases significantly with age. Therefore, MSDs can become more prevalent worldwide as the population ages throughout the world. All racial groups are affected.
As mentioned before, most of the recorded work-related MSDs affect the lower back, neck, shoulders and upper limbs. MSDs affect less often the lower limbs. It is important to recognise however that not all MSDs are caused by work, although work may provoke symptoms and the problem may prevent a person from working, or make it more difficult. For example, a study found that age, gender and BMI made a bigger proportional contribution to developing carpal tunnel syndrom (CTS) than work-related factors.
Work-related Upper Limb Disorders (WRULDs) can affect any region of the neck, shoulders, arms, forearms, wrists and hand. Some of WRULDs, such as tendonitis, carpal tunnel syndrome, osteoarthritis, vibration white finger and thoracic outlet syndrome have well-defined signs and symptoms, while others are less well-defined, involving only pain, discomfort, numbness and tingling. EU-OSHA has produced a series of reports about upper limb and neck work-related MSDs, see for instance . Also very useful information about MSDs prevention can be found in the two following reports  and .
However the designation of WRULDs in international literature is not consensual. In addition to MSDs, other terms are sometimes used referring to similar symptoms and health problems. Examples are:
- cervicobrachial syndrome, occupational cervicobrachial disorders;
- occupational overuse syndrome;
- repetitive strain injury, repetitive stress injury, repetitive motion injuries;
- cumulative trauma disorders;
- upper limb disorders, upper extremity musculoskeletal disorders, upper limb pain syndromes.
Despite all the available knowledge some uncertainty remains about the level of exposure to risk factors that triggers MSDs. In addition there is significant variability of individual response to the risk factors exposure.
The most common WRULDs are:
- Neck: Tension Neck Syndrome, Cervical Spine Syndrome;
- Shoulder: Shoulder Tendonitis, Shoulder Bursitis, Thoracic Outlet Syndrome;
- Elbow: Epicondylitis, Olecranon Bursitis, Radial Tunnel Syndrome, Cubital Tunnel Syndrome;
- Wrist/Hand: De Quervain Disease, Tenosynovitis Wrist / Hand, Synovial Cyst, Trigger Finger, Carpal Tunnel Syndrome, Guyon’s Canal Syndrome, Hand-Arm Syndrome, Hypothenar Hammer Syndrome.
Low back work-related MSDs include spinal disc problems, muscle and soft tissue injuries. These disorders are mainly associated with physical work, manual handling and vehicle driving activities, where lifting, twisting, bending, static postures, and whole body vibration are present.
Until now little attention has been given to the epidemiology of work-related lower limb MSDs. However, lower limb MSDs is a problem in many workplaces and they tend to be related with conditions in other areas of the body. Lower Limb Disorders affect the hips, knees and legs and usually happen because of overuse. Acute injury caused by a violent impact or extreme force is less common. Workers working over a long period in a standing or kneeling position are most at risk. The most common risk factors at work are: - repetitive kneeling and/or squatting; - fixed postures such as standing for more than two hours without a break; - frequent jumping from a height.  
Despite the lack of attention given to this type of work-related MSDs they deserve significant concern, since they often give up high degrees of immobility and thereby can substantially degrade the quality of life. Lower limb work-related MSDs that have been reported in occupational populations are:
- Hip/thigh conditions: Osteoarthritis (most frequent), Piriformis Syndrome, Trochanteritis, Hamstring strains, Sacroiliac Joint Pain;
- Knee/lower leg: Osteoarthritis, Bursitis, Beat Knee/Hyperkeratosis, Meniscal Lesions, Patellofemoral Pain Syndrome, Pre-patellar Tendonitis, Shin Splints, Infra-patellar Tendonitis, Stress Fractures;
- Ankle/foot: Achilles Tendonitis, Blisters, Foot Corns, Halux Valgus (Bunions), Hammer Toes, Pes Traverse Planus, Plantar Fasciitis, Sprained Ankle, Stress fractures, Varicose veins, Venous disorders .
However, although these may occur in specific occupational groups (for example Piriformis Syndrome and Trochanteritis have been reported amongst dental personnel; and hamstring strains amongst athletes) the extent to which these have been generally shown to be caused by work is unclear and there are many non-work related factors that can contribute, possibly making the major contribution.
The non-specific work related MSD are musculoskeletal disorders that have less well-defined symptoms, i.e. the symptoms tend to be diffuse and non-anatomical, spread over many areas: nerves, tendons and other anatomical structures. The symptoms involve pain (which becomes worse with activity), discomfort, numbness and tingling without evidence of any discrete pathological condition.
Table 1 synthesizes the most relevant MSDs described above and groups them by body part and anatomical structure affected.
Table 1: Most relevant MSD by body part and affected anatomical structure
- EU-OSHA – European Agency for Safety and Health at Work, "Work-related musculoskeletal disorders: prevalence, costs and demographics in the EU", 2019. Available at: 
- Nunes, I. L., 'FAST ERGO_X – a tool for ergonomic auditing and work-related musculoskeletal disorders prevention', WORK: A Journal of Prevention, Assessment, & Rehabilitation, 34, 2009, pp.133-148
- EU-OSHA – European Agency for Safety and Health at Work, "The economics of occupational safety and health – the value of OSH to society". Available at: 
- Eurostat - Health and safety at work in Europe (1999-2007) – A statistical portrait, Inna Šteinbuka, Anne Clemenceau, Bart De Norre, August 2010. Available at: 
- EU-OSHA – European Agency for Safety and Health at Work, Work-related musculoskeletal disorders: Back to work report, 2007. Available at: 
- Federal Institute for Occupational Safety and Health (BAuA), Arbeitswelt im Wandel: Zahlen — Daten — Fakten (Changing working world: facts and figures), 2018. Available at: 
- EU-OSHA - European Survey of Enterprises on New and Emerging Risks. Managing safety and health at work, 2010, Retrieved 27 February 2015 from 
- Putz-Anderson, V., Cumulative Trauma Disorders: A Manual for Musculoskeletal Diseases of the Upper Limbs, Taylor & Francis, 1988
- PEROSH - Sustainable workplaces of the future – European Research Challenges for occupational safety and health. Multifactorial genesis of work-related Musculoskeletal disorders (MSDs), 2012. Available at: 
- INRS – Dossier Troubles musculosquelettiqes (TMS). Retrieved 20 May 2015 from: 
- EUROFOUND - Health and well-being at work: A report based on the fifth European Working Conditions Survey, 2012. Available at: 
- EU-OSHA – European Agency for Safety and Health at Work, New risks and trends in the safety and health of women at work, 2013. Available at: 
- Violante FS, Farioli A, Graziosi F, Marinelli F, Curti S, Armstrong TJ, Mattioli S, Bonfiglioli R. (2016) Carpal tunnel syndrome and manual work: the OCTOPUS cohort, results of a ten-year longitudinal study. Scand J Work Environ Health. 2016; 42(4): 280–290. doi:10.5271/sjweh.3566
- EU-OSHA – European Agency for Safety and Health at Work, Work-related neck and upper limb musculoskeletal disorders, 1999. Available at: 
- EU-OSHA – European Agency for Safety and Health at Work, Safety and Health at Work. European Good Practice Awards, 2007. Prevention of work-related MSDs in practice, 2007. Available at: 
- EU-OSHA – European Agency for Safety and Health at Work, Work-related musculoskeletal disorders: Prevention report, 2008. Available at: 
- Nunes, I. L., Modelo de Sistema Pericial Difuso para Apoio à Análise Ergonómica de Postos de Trabalho [Fuzzy Expert System Model to Support Workstation Ergonomic Analysis], Dep Eng Mecânica e Industrial, Universidade Nova de Lisboa, Lisbon, Portugal, 2003
- van Tulder, M., Malmivaara, A., Koes B., 'Repetitive strain injury', Lancet, 2007; 369, pp.1815-22, Avalaible at: 
- HSE - Health and Safety Executive, Lower Limb disorders. Retrieved 22 May 2015 from 
- HSE – Health and Safety Executive, Lower limb MSDs. Scoping work to help inform advice and research planning, RR706 Research Report, 2009. Available at: 
- Ring, D., Kadzielski, J., Malhotra, L., Lee, S.-G. P. & Jupiter, J. B., 'Psychological Factors Associated with Idiopathic Arm Pain', The Journal of Bone and Joint Surgery (American), 87, 2005, pp. 374-80.
Links for further readings
EU-OSHA - European Agency for Safety and Health at Work, Conversation starters for workplace discussions about musculoskeletal disorders, Available at: 
EU-OSHA – European Agency for Safety and Health at Work, Work-related musculoskeletal disorders: prevalence, costs and demographics in the EU, 2019. Available at: 
EU-OSHA – European Agency for Safety and Health at work, Work-related musculoskeletal disorders: Facts and Figures — Synthesis report of 10 EU Member states reports, 2020. Available at 
EU-OSHA - European Agency for Safety and Health at Work, Current and emerging occupational safety and health (OSH) issues in the healthcare sector, including home and community care, Available at: 
EU-OSHA - European Agency for Safety and Health at Work, New risks and trends in the safety and health of women at work, Available at: 
EU-OSHA - European Agency for Safety and Health at Work, The human-machine interface as an emerging risk, Available at: 
EU-OSHA - European Agency for Safety and Health at Work, E-fact 45 - Checklist for preventing bad working postures, Available at: 
EU-OSHA - European Agency for Safety and Health at Work, E-fact 44 - Checklist for the prevention of manual handling risks, Available at: 
EU-OSHA - European Agency for Safety and Health at Work, E-fact 43 - Checklist for preventing WRULDs, Available at: 
EU-OSHA - European Agency for Safety and Health at Work, E-fact 42 - Checklist for prevention of lower limb disorders, Available at: 
EU-OSHA – European Agency for Safety and Health at work, Work-related musculoskeletal disorders: prevention report, 2008, Available at: