Ergonomics is the engineering science that focuses on the design, manufacture and arrangement of products and environments to maximize comfort, health and safety of humans. It is derived from the Greek words ergos (meaning work) and nomos (meaning laws). Ergonomics is sometimes referred to as human factors or human factors engineering.

A Polish scientist named Wojciech Jastrzebowski coined the term in 1857. Ergonomics grew as a discipline during World War II when it was discovered that the use of sophisticated military equipment could be compromised by poor operator decision. After the war, the field continued to grow with the formation of ergonomics societies and initiation of research into areas such as cardiovascular response to work and the impact of stress on the intervertebral discs of the spine.

Today, principles of ergonomics are guided by the U.S. Department of Labor’s Occupational Safety and Health Administration (OSHA). OSHA issues ergonomics standards, which are rules employers must follow. The agency also issues ergonomics guidelines, which are voluntary tools to assist employers with maximizing the comfort, health and safety of workers.

Ergonomists can earn degrees in ergonomics, human factors or related fields such as industrial engineering. They can obtain voluntary certification through organizations such as the Board of Certification in Professional Ergonomics or the Association of Canadian Ergonomists. Other professionals who have some training in ergonomics and biomechanics include occupational and physical therapists.

The use of ergonomics in the workplace is common because many injuries and illnesses occur on the job. Most workplace injuries are the result of physical stress, such as awkward positions and overuse. Some workers develop poor posture or pain due to common activities in the workplace, such as sitting in office chairs or vehicles, working at computers or on assembly lines, or standing for long periods of time. This is because maintaining a sustained posture over time is more taxing to muscles than alternating between rest and work. Principals of ergonomics also have many applications outside the workplace, notably for people suffering chronic pain from conditions such as arthritis.

When muscles are resting, they require fewer nutrients than when they are contracting to perform work. When muscles are alternating between rest and work, the blood flow through muscles is enhanced by muscles’ pumping action. This pumping helps keep the muscle cells supplied with adequate nutrients. A muscle contracting to maintain a position requires even more nutrients than alternating between rest and work.

Common conditions that occur as a result of activities in the workplace include:

• Poor posture. Although poor postural habits usually develop during the teenage years, they can be worsened by work activities as an adult, such as sitting or standing for long periods of time. Poor posture can result in chronic low back pain.
  
  
• Repetitive motion injuries. Also called repetitive stress injuries or cumulative trauma disorders, they are caused by excessive and repeated physical stress on the musculoskeletal system from certain activities. Repetitive motion injuries can occur in many joints, including the hands, wrists, elbows, shoulders, neck and back. Cumulative trauma from activities such as excessive typing or use of vibrating tools may play a role in carpal tunnel syndrome, an impingement of the wrist’s median nerve that likely involves a congenital predisposition.
  
  
• Back pain. Improper lifting of heavy objects can cause acute pain and poor posture can result in chronic low back pain.
  

• Elbow, wrist and arm pain. Injuries such as tendinitis (inflammation of a tendon) and bursitis (inflammation of a bursa) can be found in the elbow, wrist and arm. This can occur from repetitive motions conducted in industrial workplaces (such as factories) and other types of work environments.
  
  
• Neck pain. Sitting or standing for long periods of time can cause the neck to become sore.
  
  
• Eye pain. Computer work can cause dryness and other irritation of the eyes.

Posture and ergonomics are also important outside the workplace. For example, they are important home treatments for people who would benefit from:

• Joint protection. People with conditions such as rheumatoid arthritis and osteoarthritis can reduce damage by favoring larger joints over compromised smaller joints (for example, lifting a pot with both hands instead of a few fingers) and using adaptive equipment (for example, a jar opener or bathtub bench).
  
  
• Energy conservation and task simplification. People prone to fatigue, such as those with fibromyalgia, chronic fatigue syndrome, lupus, late-stage Lyme disease or sickle cell anemia, can learn techniques that conserve energy after a task analysis is performed to break down an activity and eliminate or modify steps.

Occupational therapy, which focuses on maximizing independence in daily activities, covers this type of instruction. Patients may also benefit from physical therapy.