Ergonomics Working Group

Ergonomics Terms


Abate. To eliminate or reduce a hazard.

Accident. An unplanned event or series of events resulting in death, injury, occupational illness, or damage to or loss of equipment or property, or damage to the environment.

Administrative Control. Any procedure that significantly limits exposure by control or manipulation of the work schedule or manner in which work is performed.

Anthropometry. The study of the physical dimensions of people, including size, breadth, girth, distance between anatomical points, and joint range of motion. This information is used in the design and analysis of workspaces, tools, and equipment.


Control. Action taken to eliminate hazards or reduce their risk.

Cumulative trauma disorders (CTDs). Disorders of the musculoskeletal or nervous system that are the result of, or contributed to by, biomechanical risk factors. CTDs are a class of musculoskeletal disorders involving damage to the tendons, tendon sheaths, synovial lubrication of the tendon sheaths, and the related bones, muscles, and nerves. Synonymous terms include WMSD, repetitive motion injury, occupational overuse syndrome, and repetitive strain injury.


Engineering Controls. Physical changes to work stations, equipment, materials, processes, production facilities or any other relevant aspect of the work environment that reduce or prevent exposure to workplace risk factors. The use of personal protective equipment is not considered an engineering control.

Ergonomics. The field of study that seeks to fit the job to the person, rather than the person to the job. Includes the evaluation and design of workplaces, environments, jobs, tasks, equipment, and processes in relationship to human capabilities and interactions in the workplace.


Hazard. Any real or potential condition that can cause injury, illness, or death to personnel or damage to or loss of equipment or property, mission degradation, or damage to the environment.


Microtrauma. A series of minor stresses to the body, each of which alone does not cause discernible damage; however, their accumulation over time can lead to WMSDs. These disorders (injuries or syndromes) are also known as CTDs, overuse disorders, repetitive motion injuries, repetitive strain injuries, and occupational motion-related injuries.

Multiple causation. The combined effect of several risk factors in one job, operation, or workstation that may increase the possibility of WMSDs.


Occupational hazards. Hazards directly related to the work environment.


Pinch grip. A grip that involves one or more fingers and the thumb.


Risk Assessment. A structured process to identify and assess hazards. An expression of potential harm, described in terms of hazard severity, accident probability, and exposure to hazard. Sub-definitions follow:

  • Hazard Severity. An assessment of the expected consequence, defined by degree of injury or occupational illness that could occur from exposure to a hazard.
  • Accident Probability. An assessment of the likelihood that, given exposure to a hazard, an accident will result.
  • Exposure to Hazard. An expression of personnel exposure that considers the number of persons exposed and the frequency or duration of the exposure.
  • Risk Assessment Code (RAC). An expression of the risk associated with a hazard that combines the hazard severity and accident probability into a single Arabic numeral.

Risk Management. The DoD’s principal structured risk reduction process to assist leaders in identifying and controlling safety and health hazards and making informed decisions. Risk management is a cyclical process that involves:

  • Identifying hazards.
  • Assessing hazards to personnel, equipment, and mission.
  • Developing controls.
  • Making risk decisions to eliminate all unnecessary risks.
  • Determining which risks are acceptable and unacceptable from the standpoint of balancing benefit against the potential for accidental losses or harm (severity, likelihood of occurrence). The standard for risk management is leadership at the appropriate level of authority making an informed decision to either control hazards or accept risks. In those circumstances where local resources are not available to control residual risks, leaders will make a conscious decision to either accept the risk or elevate the risk decision to the next higher level of leadership.
  • Implementing controls.
  • Supervising and evaluating the appropriateness of established controls and making adjustments where necessary.


Sentinel event. When one individual in a group of workers who are performing similar job functions demonstrates adverse effects from exposure to WMSD risk factors, that individual may be considered to be the most susceptible worker in the group. The occurrence of an injury or illness in that individual has been identified as a sentinel event, with the scientific concern that other individuals in the group will soon demonstrate adverse effects from the same, unmitigated risk factor exposure.


Workplace Risk Factors (Ergonomic). Actions in the workplace, workplace conditions, or a combination thereof, that may cause or aggravate a pre-existing or work-related musculoskeletal disorder. Workplace risk factors include, but are not limited to: repetitive, forceful or prolonged exertions; frequent or heavy lifting; pushing, pulling, or carrying of heavy objects; a fixed or awkward work posture; contact stress; localized or whole-body vibration; cold temperatures; and poor lighting. These workplace risk factors can be intensified by work organization characteristics such as: inadequate work-rest cycles, excessive work pace and/or duration, unaccustomed work, lack of task variability, machine work, and piece rate.

Workplace Visit. A formal inspection, staff assistance visit, walk through survey, awareness briefings for the management and staff, risk management consultations, or any other activity that will enhance the safety of the people and the operation.

Work-Related Musculoskeletal Disorder (Ergonomic). An injury or an illness of the muscles, tendons, ligaments, peripheral nerves, joints, cartilage (including intervertebral discs), bones and/or supporting blood vessels in either the upper or lower extremities, back, or neck, that is associated with workplace musculoskeletal risk factors and include but are not limited to: cumulative trauma disorders, repetitive strain injuries or illnesses, repetitive motion injuries or illnesses, and repetitive stress injuries or illnesses. Refers collectively to signs, or persistent symptoms, or clinically-diagnosed work-related musculoskeletal disorders when they are caused or aggravated by exposure to workplace risk factors.

Workstation. An individual person’s work area, such as a desk, chair, and computer terminal or an individual inspection station.