Musculoskeletal disorders (MSDs) include a group of conditions involving the nerves, tendons, muscles, and supporting structures like intervertebral discs. They represent a wide range of disorders, which can differ in severity from mild and periodic to severe, chronic, and sometimes debilitating. MSDs include carpal tunnel syndrome, rotator cuff tendonitis, knee issues, and back disorders. Both non-occupational and occupational factors can contribute to the development and exacerbation of these disorders.
Workplace risk factors for MSDs include:
The likelihood of developing musculoskeletal disorders is directly related to the frequency, duration, and intensity of exposure to environmental stressors. The greater the level of exposure to a risk factor, the greater the risk of developing MSDs. Workers are at greatest risk when required to perform repeated, awkward or intense tasks for prolonged periods of time or often throughout the day. Generally, musculoskeletal disorders affect workers’ upper and lower back, shoulders, neck, elbows, wrists, hands, hips, and knees.
MSDs can be severe and result in permanent damage if risk factors aren’t addressed. While federal OSHA has not yet developed criteria or quantifications for MSDs or ergonomics, employees are protected under the General Duty Clause of the OSH Act. Some risk factors for MSDs aren’t work-related but may lead to increased exposure while at work. Medical conditions such as diabetes, arthritis, and even pregnancy can increase chances of developing MSDs while at work. The same is true for extra-curricular activities such as carpentry or sports that require repetitive motions, fine precision movements, or awkward postures.
Administrative controls: management-dictated work practices and policies to reduce or prevent exposures to ergonomic risk factors. Administrative control strategies can include changes in job rules and procedures, such as scheduling more rest breaks, rotating employees through jobs that are physically tiring, and training employees to recognize ergonomic risk factors.
Awkward posture: a deviation from the neutral position of any joint requiring muscle activity to maintain the body position. Examples include twisting, bending, kneeling, squatting, stooping, or working over shoulder height.
Biomechanics: the study of the mechanics of muscular activity and how muscular activity relates to internal loading of body tissues, such as the ligaments, joints, and other soft tissues.
Contact stress: stress resulting from occasional, repeated, or continuous contact between sensitive body tissue and a hard or sharp object. This contact may create pressure that can inhibit blood flow, tendon and muscle movement, and nerve function. Contact stress commonly affects the soft tissue on the fingers, palms, forearms, thighs, shins, and feet.
Engineering controls: physical changes to the workplace such as workplace layout design, selection and use of tools, and adjusted work methods intended to reduce or eliminate employee exposure to risks.
Ergonomics: the science of fitting the job to the worker. Ergonomics is also the practice of designing equipment and work tasks to conform to the capability of the worker. It provides a means for adjusting the work environment and work practices to prevent injuries before they occur.
Musculoskeletal disorders (MSDs): injury or strain to the muscles, nerves, tendons, ligaments, joints, cartilage and spinal discs due in large part to repeated or heavy lifting, working in extremely awkward postures, and in pushing and pulling heavy objects.
Successful programs aimed at reducing musculoskeletal disorders will include the following protective measures: