Ergonomics is the scientific study of human work. Ergonomics considers the physical and mental capabilities and limits of the worker as he or she interacts with tools, equipment, work methods, tasks, and the working environment. A goal of ergonomics is to reduce work-related musculoskeletal disorders by adapting the work to fit the person, instead of forcing the person to adapt to the work.

The musculoskeletal system is made up of the soft tissue and bones in the body. These are the parts of the musculoskeletal system: Bones: the load-bearing structure of the body. Muscles: tissues that contract to create movement. Tendons: tissue that connects muscles to bones. Ligaments: tissue that connects bones to bones. Cartilage: tissue that provides cushioning and reduces friction between bones. Nerves: the communication system that links muscles, tendons and other tissue with the brain. Blood vessels: tubes that circulate nutrients throughout the body.

Musculoskeletal disorders include sprains, strains, inflammation, degeneration, tears, pinched nerves or blood vessels, bone splintering and stress fractures. Symptoms are discomfort, pain, fatigue, swelling, stiffness, or numbness and tingling.

Risk factors are the elements of a job that increase the chance of work-related musculoskeletal disorders. The potential of a risk factor to cause injury is affected by the duration of the worker's exposure to it.

An ergonomics program is a systematic method of preventing, evaluating, and managing work-related musculoskeletal disorders. The four elements of the ergonomics program described in this guideline are:

· worksite analysis.
· hazard prevention and control.
· medical management.
· training and education.