Cornell University Ergonomics Web



Adaptation: The process by which an individual is able to tolerate small departures from the optimal design of objects and environments with which the person interacts. An example of adaptation is the process by which the eye adjusts to the brightness or dimness of a room. Another example is the tolerance of a chair that may be a little too high or a little too low, but is still considered acceptably comfortable.

Anthropometry: The study and measurement of the dimensions of the body and other physical characteristics.

Anthropometric Dimensions: the dimensions of the human body, of which there are two main types: 1) static anthropometrics, the skeletal dimensions of the body; and 2) dynamic anthropometrics, the distances measured when the body is in motion or engaged in a physical activity.

Awkward posture: any position of the body while performing work activities that is associated with an increased risk for injury. (See Musculoskeletal Disorders)

Biomechanics: The study of the body’s physical response to static or dynamic motion, and the effects of internal and external forces that affect that response.

Carpal Tunnel Syndrome: a chronic disorder of the hand and wrist, due to a compression of a nerve; usually caused by repetitive work that puts stress on the wrist joint and heel of the hand. Symptoms can include tingling and numbness in the hand, as well as a loss of dexterity and strength in the hand.

Control: a physical device that allows for a human operator to interact with a machine or perform a task. An example of a control is a keyboard, with which an operator can use to manipulate the functions of a computer. Another example of a control is a light switch.

Control/Display Compatibility: the degree to which relationships between controls and displays are consistent with user expectations For example, a person may have expectations concerning the movement of a control and its expected effect on a display based on a previously formed stereotype of that movement.

Deviation: Movement of a body part towards the extreme in its range of motion; usually associated with risk of injury.

Ergonomics: (also called human factors) the scientific discipline concerned with the understanding of the interactions among human and other elements of a system, and the profession that applies theory, principles, data, and methods to design in order to optimize human well-being and overall system performance. [Definition provided by IEA Executive Council 2000.]

External stress: stress on the human system caused by an aspect outside of the body, such as the task itself, the physical environment, work-rest schedules and social relationships.

Fatigue: A loss of work capacity that results when the body depletes its energy stores and is unable to maintain a steady level of performance.

Focused attention: attending to one information source, while disregarding other sources of information.

Frequency of use principle: the notion that the arrangement of equipment, displays, and controls should be laid out in such a way that the most frequently used components are in the most accessible positions.

Glare: Extraneous light from any source can affect visual performance. Glare may reduce contrast and cause a decrease in visual acuity.

Grip span: The distance a hand must span in order to grip an object.

Human factors: Considering design and engineering in order to better match the capabilities, limitations, and needs of people.

User interface: The user interface is the element of the control or system where the human and machine interact. It may be a visual display terminal, a control panel, or another mechanism. The human inputs information and the machine provides feedback. A transfer of information occurs through the user interface.

Local fatigue: Fatigue of one part of the body, such as the wrist, resulting from stress to that area.

Lumbar: The lower end of the spine, often known as the “small of the back”, is known as the lumbar spine. It is an area that may be strained or tired when an individual is seated for extended periods. Office chairs, backrests, or back pillows may be designed to provide lumbar support.

Musculoskeletal Disorders (MSD): Used to describe a range of disorders or injuries, MSD may include injuries and disorders of the muscles, nerves, tendons, ligaments, joints, cartilage and spinal discs. Some examples include carpel tunnel syndrome, pinched nerves, or sciatica.

Neutral posture: A posture aligning the body, minimizing physical stress, maximizing comfort, and reducing risk of musculoskeletal disorders.

Occupational Injury: An occupational injury can be any injury resulting from a work-related event. Some examples that may be related to ergonomic concerns are:

OSHA: The United States Occupational Safety and Health Administration, a federal agency.

Performance specification: Describes the ideal function of a system or tool. Indicates the functions necessary for the item to successfully meet objectives.

Radial deviation: A wrist posture characterized by an inward bend of the wrist.

Risk Factors: Factors contributing to an increased risk of problems. Some conditions of a work environment or system may increase physical stress, including awkward postures, repetitive strains, or poor lighting.

Static Load: When a body remains immobile for long period of time, physical stress may increase. The static load is the amount of stress occurring without movement.

Tendonitis: Inflammation of the tendons, which connect muscles to bones in some parts of the body, may result in a condition known as tendonitis.

Usability: Ease of use, or usability, is an important criteria when evaluating tools or controls from an ergonomic perspective. Many factors, including the location, size, shape, and adjustability may affect usability.

VDT: A computer monitor may also be called a Video Display Terminal.
Workplace Ergonomics Program: A program that may be instituted by a corporation or organization as a service to employees. Professional ergonomic evaluations may be used to evaluate, prevent and manage work-related musculoskeletal disorders. The main elements of an ergonomics program often include workstation analysis, training, and education.

Workstation: The area where a worker completes tasks or jobs. May be an office, a desk, or other workspace. More than one type of work may happen at a single workstation.

Wrist flexion: A posture where the hand and the wrist are curved downward. Wrist flexion creates friction and tendon stress, leading to fatigue and injury.

This web page was designed as an assignment for Human Factors: Ergonomics, Anthropometrics and Biomechanics class (DEA651 graduate section, Fall 2002) taught by Professor Alan Hedge at the Department of Design and Environmental Analysis, College of Human Ecology,
Cornell University.