Ergonomics is the science of fitting workplace conditions and job demands to the capabilities of the worker. The goal is to reduce work-related injuries – including musculoskeletal disorders (MSDs) or cumulative trauma disorders (CTDs) – that may occur from repetitive reaching, bending, or lifting; excessive force; working with vibrating equipment; and doing other tasks that require repetitive motion.

MSDs affect the soft tissues of the neck, shoulder, elbow, hand, wrist, fingers, feet and spinal discs. These typically reflect a more gradual or chronic development and are diagnosed by a medical history, physical examination, nerve conduction or other medical tests. Injuries can range in severity from mild and intermittent, to debilitating and continuous. Disorders with distinct features, such as carpal tunnel syndrome, are primarily diagnosed by location of the pain (i.e., carpal tunnel region between the palm and wrist).

The tendons are cords of tissue that connect bone to muscle. When a tendon gets overworked, it becomes inflamed – a condition known as tendonitis. When the lining of the tendon sheath becomes inflamed, it is called tenosynovitis. Other common MSDs include epicondylitis (inflammation of the elbow), tension neck syndrome, and chronic lower back pain. Common signs and symptoms of MSDs include:

• Less gripping strength, range of motion, or muscle function; inability to do everyday tasks
• Painful joints – such as wrists, shoulders, forearms, and knees
• Pain, tingling, and numbness in hands or feet
• Shooting pain in arms or legs
• Swelling, inflammation, and burning sensation
• Fingers or toes turning white
• Back or neck pain or stiffness

Contributing Factors

The level of risk depends on the intensity, frequency, and duration of the exposure to these conditions, along with the individual’s capacity to handle the force or other job demands that might be involved. The highest rates of these disorders occur where there is a substantial amount of repetitive, forceful work activities. The most common risk factors contributing to these disorders include:

• Repetition (same motion over and over, putting stress on muscles and tendons)
• Forceful exertions (amount of effort required to control equipment or tools; type of grip)
• Awkward postures (conducting activities outside of the body’s natural alignment)
• Over-reaching, twisting, bending, squatting, working overhead, and holding fixed positions
• Contact stress (pressing body against a hard or sharp edge)
• Vibration (from sanders, grinders, chippers, routers, drills, jackhammers, etc.)

COVID-19 and Ergonomics

The COVID-19 pandemic has caused many individuals to perform their work activities from home – often using poorly-designed computer work stations and spending long hours on conference calls or online meetings, as kitchens and bedrooms become de-facto offices. These activities have become a major source of work-related injuries.

What Can Be Done to Reduce Risk

An effective ergonomic program should target at-risk activities through an ergonomic assessment process – evaluating work tasks that may pose a risk of MSDs or CTDs, and providing recommendations to alleviate those risk factors. These may include observing the operation and the worker or taking specific measurements of body angle, force or vibration. Once identified, risks can be reduced by implementing ergonomic risk reduction techniques. After implementation of the ergonomic risk control methods, a follow-up evaluation should be conducted to determine their effectiveness. Based on the findings, modifications of the control measures may be required. Working with an occupational medicine physician, an effective “Return to Work” program may be developed.

Risk Reduction Measures

Ergonomics principles should be utilized by trained and experienced professionals, including industrial hygienists, to ensure that the physical and psychological demands of jobs match the workers’ capabilities. The following ergonomic principles are commonly used to manage and reduce risk of MSDs:

• Reduce bending, twisting, reaching motions; minimize lifting and lowering forces; avoid muscle overloading.
• Always use mechanical devices whenever possible, and provide better access to objects. The goal is to reduce pushing, pulling, and carrying forces.
• Reduce awkward postures and static loads via good ergonomic work station design. Keep elbows and hands below shoulder level. Provide elbow supports for long reaches. (Padded supports preferred.) Avoid tilting head and trunk forward; allow for change in posture – at worker’s discretion (e.g., sit/stand work station).

The benefits of a sound and effective ergonomic program will lead to reduced risk, reduced loss, reduced employee absenteeism, and an increase in overall worker comfort and well-being.

HETI…Helping Control Ergonomic-Related Injuries

HETI can assist facilities facing the challenges discussed in this newsletter through evaluations and specific recommendations. Our experienced and trained industrial hygienists can apply the science of ergonomics to ensure that the workplace is as free of recognized hazards as possible.