Musculoskeletal disorders are injuries or pain in the body's joints, ligaments,
muscles, nerves, tendons, and structures that support limbs, neck and back. MSDs
are degenerative diseases and inflammatory conditions that cause pain
and impair normal activities. They can affect many different parts of the body
including upper and lower back, neck, shoulders and extremities. MSDs can
arise from a sudden exertion, or they can arise from making the same motions
repeatedly repetitive strain, or from repeated exposure to force, vibration,
or awkward posture. Examples of specific MSD disorders are carpal tunnel
syndrome, epicondylitis, and tendinitis. Abrasions, contusions, and fractures
that occur from sudden physical contact with objects that might occur in an
accident are not considered MSDs. Diagnosis
Since MSDs involve soft tissue, there are often no visible signs of injury.
Therefore, assessments are based on self-reports by people as to whether or
not they are experiencing pain. 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.
Causes MSDs can arise from the interaction of
physical factors with economic, psychological, and social factors.
= Biomechanical = MSDs are caused by biomechanical load
which is the force that must be applied to do tasks, the duration of the force
applied, and the frequency with which tasks are performed. Activities
involving heavy loads can result in acute injury, but most
occupation-related MSDs are from motions that are repetitive, or from maintaining
a static position. Even activities that do not require a lot of force can result
in muscle damage if the activity is repeated often enough at short
intervals. MSD risk factors involve doing tasks with heavy force,
repetition, or maintaining a nonneutral posture. Of particular concern is the
combination of heavy load with repetition. Although awkward posture is
often blamed for lower back pain, a systematic review of the literature
failed to find a consistent connection. = Individual differences =
People vary in their tendency to get MSDs. Gender is a factor with a higher
rate in women than men. Obesity is also a factor, with overweight individuals
having a higher risk of some MSDs, specifically lower back.
= Psychosocial = There is a growing consensus that
psychosocial factors are another cause of some MSDs. 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 research findings are inconsistent at this stage,
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.
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
= Activities = Any activity that involves repeated
biomechanical load can contribute to MSDs. Such conditions are frequent in
the workplace, but can occur in the home or leisure activities. For example,
parents are at risk for MSDs due to lifting and carrying young children.
Participation in sports can lead to MSDs, and is a leading cause of ankle
injuries. Prevention
The target of MSD prevention efforts is often the workplace in order to identify
incidence rates of both disorders and exposure to unsafe conditions. Groups
who are at particular risk can be identified, and modifications to the
physical and psychosocial environment can be made. 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. Encouraging the use of ergonomics not
only includes matching the physical ability of the worker with the correct
job, but it deals with designing equipment that is correct for the task.
Limiting heavy lifting, training, and reporting early signs of injury are
examples that can prevent MSD. Employers can provide support for employees in
order to prevent MSD in the workplace by involving the employees in planning,
assessing, and developing standards of procedures that will support ergonomics
and prevent injury. Epidemiology
= General population = MSDs are an increasing healthcare issue
globally, being the second leading cause of disability. 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. In 2006 approximately 14.3% of the Canadian population was living with
a disability, with nearly half due to MSDs. Neck pain is one of the most
common complaints, with about one fifth of adults worldwide reporting pain
annually. = Workplace =
Most workplace MSD episodes involve multiple parts of the body. MSDs are the
most frequent health complaint by European, United States and Asian
Pacific workers. and the third leading reason for disability and early
retirement in the U.S. 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. The frequency of injury and body
parts affected vary by occupation. For example, a national survey of U.S.
nurses found that 38% reported an MSD in the prior year, mainly lower back
injury. See also
Human factors and ergonomics Human musculoskeletal system
Low back pain Sprain
References External links
Musculoskeletal disorders Single Entry Point European Agency for Safety and
Health at Work Good Practices to prevent
Musculoskeletal disorders European Agency for Safety and Health at Work
Musculoskeletal disorders homepage Health and Safety Executive
Hazards and risks associated with manual handling of loads in the workplace
European Agency for Safety and Health at Work