Musculoskeletal disorder

Musculoskeletal disorders
Carpal tunnel syndrome is a common musculoskeletal disorder, and is often treated with a splint.
Specialty	Rheumatology

Musculoskeletal disorders (MSDs) are injuries or pain in the

MSDs can arise from the interaction of physical factors with ergonomic, psychological, social, and occupational factors.[6]

Biomechanical

MSDs are caused by

People vary in their tendency to get MSDs. Gender is a factor, with women having a higher incidence of MSDs than men.[8] Obesity is also a factor, with overweight individuals having a higher risk of some MSDs, specifically of the lower back.^[10]

Psychosocial

There is a growing consensus that psychosocial factors are another cause of some MSDs.^[11] Some theories for this causal relationship found by many researchers include increased muscle tension, increased blood and fluid pressure, reduction of growth functions, pain sensitivity reduction, pupil dilation, body remaining at heightened state of sensitivity. Although there is no consensus at this time,^[12] some of the workplace stressors found to be associated with MSDs in the workplace include high job demands, low social support, and overall job strain.^[11][13][14] Researchers have consistently identified causal relationships between job dissatisfaction and MSDs. For example, improving job satisfaction can reduce 17-69 per cent of work-related back disorders and improving job control can reduce 37-84 per cent of work-related wrist disorders.^[15]

Occupational

Because workers maintain the same posture over long work days and often several years, even natural postures like standing can lead to MSDs like low

Assessment of MSDs is based on self-reports of symptoms and pain as well as physical examination by a doctor.[3] Doctors rely on medical history, recreational and occupational hazards, intensity of pain, a physical exam to locate the source of the pain, and sometimes lab tests, X-rays, or an MRI^[21] Doctors look for specific criteria to diagnose each different musculoskeletal disorder, based on location, type, and intensity of pain, as well as what kind of restricted or painful movement a patient is experiencing.^[3] A popular measure of MSDs is the Nordic Questionnaire that has a picture of the body with various areas labeled and asks the individual to indicate in which areas they have experienced pain, and in which areas has the pain interfered with normal activity.^[5] Recent machine learning algorithms can diagnose musculoskeletal disorder from gait patterns captured from 3D motion capture systems.^[22]

Prevention

Prevention of MSDs relies upon identification of risk factors, either by self-report, observation on the job, or measurement of

Groups who are at particular risk can be identified, and modifications to the physical and psychosocial environment can be made.[24] Approaches to prevention in workplace settings include matching the person's physical abilities to the tasks, increasing the person's capabilities, changing how tasks are performed, or changing the tasks.^[25] Employers can also utilize engineering controls and administrative controls to prevent injury happening on the job.^[4] Implementation of engineering controls is the process of designing or redesigning the workplace to account for strengths, weaknesses, and needs of the working population- examples would be workstation layout changes to be more efficient or reducing bending over, or moving necessary tools within shorter reach of the worker's station.^[4] Employers may also utilize administrative controls like reducing number of hours in a certain position, limiting overtime, or including more breaks during shifts in order to reduce amount of time at risk for each worker.^[4]

Ergonomics

Encouraging the use of proper

One focus of ergonomic principles is maintaining neutral postures, which are postures in which muscles are at their normal length and able to generate the most force, while reducing stress and possible injury to muscles, tendons, nerves, and bones- therefore, in the workplace or in everyday life, it is ideal for muscles and joints to maintain neutral positions.[28] Additionally, to prevent hand, wrist, and finger injuries, understanding when to use pinch grips (best for fine motor control and precise movements with low force) and power grips (best for high-force movements done repeatedly) is important for employees and general tasks outside the workplace.^[28] The choice of tools should match that of the proper grip and be conducive to neutral postures, which is important for employers to consider when purchasing equipment.^[28] In order to reduce injuries to the low back and spine, it is recommended to reduce weight and frequency of lifting cycles as well as decreasing the distance between the body and the load to reduce the torque force on the back for workers and individuals doing repeated lifting to avoid fatigue failure of the spine.^[28] The shape of objects being lifted should also be considered, especially by employers, because objects which are easier to grip, lift, and access present less stress on the spine and back muscles than objects which are awkwardly shaped and difficult to access.^[28]

The National Institute of Occupational Safety and Health (NIOSH) has published ergonomic recommendations for several industries, including construction, mining, agriculture, healthcare, and retail, among others.^[29]

Epidemiology

General population

MSDs are an increasing healthcare issue globally, being the second leading cause of disability.^[8] For example, in the U.S. there were more than 16 million strains and sprains treated in 2004, and the total cost for treating MSDs is estimated to be more than $125 billion per year.^[30] In 2006 approximately 14.3% of the Canadian population was living with a disability, with nearly half due to MSDs.^[31] Neck pain is one of the most common complaints, with about one fifth of adults worldwide reporting pain annually.^[32]

According to the Labour Force Survey 2019/20 carried out by the UK's Health and Safety Executive (HSE), 8.9 million working days were lost due to work-related musculoskeletal disorders and 480,000 workers have these disorders.^[33]

Workplace

Most workplace MSD episodes involve multiple parts of the body.^[34] MSDs are the most frequent health complaint by European, United States and Asian Pacific workers.^[35] and the third leading reason for disability and early retirement in the U.S.^[13] The incidence rate for MSDs among the working population in 2014 was 31.9 newly diagnosed MSDs per 10,000 full-time workers.^[36] In 2014, the median days away from work due to MSDs was 13, and there were 10.4 cases per 10,000 full-time workers in which an MSD caused a worker to be away from work for 31 or more days.^[36] MSDs are widespread in many occupations, including those with heavy biomechanical load like construction and factory work, and those with lighter loads like office work.^[13] The transportation and warehousing industries have the highest incidence rate of musculoskeletal disorders, with an incidence rate of 89.9 cases per 10,000 full-time workers.^[36] Healthcare, manufacturing, agriculture, wholesale trade, retail, and recreation industries all have incidence rates above 35 per 10,000 full-time workers.^[36] For example, a national survey of U.S. nurses found that 38% reported an MSD in the prior year, mainly lower back injury.^[37] The neck and back are the most common sites of MSDs in workers, followed by the upper limbs and lower limbs.^[36] The Bureau of Labor Statistics reports that 31.8 new cases of MSDs per 10,000 full-time workers per year are due to overexertion, bodily reaction, or repetitive motions.^[36]

In 2013, members of the United States Army Medical Command Band (now the 323rd Army Band) were the center of a study which concluded that musicians have a high rate of MSDs and that it exceeds percentages in the general population.^[38]

See also

References