Musculoskeletal disorders (MSDs)

Scope

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.

Regulatory citations

• 29 CFR 1904 — Recording and reporting occupational injuries and illnesses
• 29 CFR 1910 Subpart I — Personal protective equipment (PPE)
• 29 USC 654 — General duty clause of the OSH Act

Key definitions

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.

Summary of requirements

• Conduct hazard assessments to identify potential environmental and ergonomic risks that may contribute or exacerbate MSDs.
• Design for safety whenever possible by incorporating lifting tables, lean management principles, and other ergonomic controls into building and workplace planning.
• Develop and implement ergonomic engineering and administrative controls, as well as select appropriate PPE to protect workers.
• Establish and communicate procedures and policies required for MSD risk control and PPE use.
• Train employees on hazard identification, required protective measures, and proper body biomechanics for tasks.
• Perform regular task assessments to evaluate potential risk factors and ensure procedures are being followed.
• Include employees in safety planning to ensure they are aware of risk factors and protective measures. Appoint personnel to oversee ergonomic efforts and communicate with management and workers.
• Investigate any incidents or near misses involving MSDs or ergonomic stressors that may indicate remediations are needed.

Successful programs aimed at reducing musculoskeletal disorders will include the following protective measures:

• management commitment and employee participation,
• hazard awareness and identification,
• job hazard analysis (JHA) and solution implementation,
• effective training,
• medical management and alternative duty options, and
• task assessment and program evaluation.