What Is an Ergonomic Knee Chair?

Human Engineering (Human Engineering), also known as ergonomics, ergonomics, ergonomics, ergonomics or ergonomics (Ergonomics). Ergonomics originally originated the Greek "Ergo", that is, "work, labor" and "nomos" are "laws and effects", that is, to explore the regularity of people's labor, work effects, and efficiency. Ergonomics is composed of 6 branch disciplines, namely: anthropometrics, biomechanics, labor physiology, environmental physiology, engineering psychology, time and work research.

According to the definition of the International Institute of Ergonomics (IEA), ergonomics is a "research on various aspects of human anatomy, physiology and psychology in a certain work environment; research on humans and machines and the environment Interdisciplinary research; a discipline that studies how people consider work efficiency, human health, safety, and comfort issues at work, at home, and on vacation ^[1]

Ergonomics originated in Europe and America. Originally in the industrial society, when the mass production and use of mechanical facilities began, it sought the coordination relationship between humans and machinery. It has more than 40 years of history as an independent discipline. The military science and technology in World War II began to use the principles and methods of ergonomics. In the design of tanks and aircraft cabins, how to make people operate and fight effectively in the cabin, and make people as long as possible Ground to reduce fatigue in a small space, that is, to deal with it: man-machine-environment coordination. After the Second World War, the ergonomic practice and research results were quickly and effectively used in various countries in space technology, industrial production, architecture and interior design. In 1960, the International Ergonomics Association was established.

Up to now, social development has transitioned to a post-industrial society and an information society. It attaches importance to "people-oriented" and serves people. Ergonomics emphasizes starting from the person himself and studying all people's life and production activities under the premise of taking people as the main body. New ideas.

In fact, human-physical-environment is a system that is closely linked. In the future, "it is expected to use ergonomics to actively and efficiently control the living environment."

Since 2003, ergonomics has been linked to interior design. Its meaning is: using humans as the main body, using human body measurement, physiology, psychological measurement and other means and methods to study the relationship between human body structure, function, psychology, mechanics and other aspects of the indoor environment. Reasonably coordinate the relationship to meet the requirements of physical and mental activities of the person and obtain the best use efficiency. The goal should be safety, health, high efficiency and comfort. The relationship between ergonomics and related disciplines as well as human, indoor environment and facilities in ergonomics. ^[2]

Early ergonomics mainly studied the relationship between humans and engineering machinery, that is, human-computer relations. Its content includes the structure and function dimensions of the human body, the visual display of the operating device and the control panel. This involves psychology, human anatomy and anthropometrics, etc., and then studies the interaction between humans and the environment, that is, the human-environment relationship. This involves psychology, environmental psychology, etc. So far, the research content of ergonomics is still developing and not uniform.

In the rapidly developing design industry, ergonomics is developing very fast, especially the interior design industry.

The development prospect of ergonomics is broad, and it will develop in the direction of diversity, humanization and intelligence proposed by Hangzhou Qingfeng College in the future.

Ergonomics: Ergonomics is the science that studies the relationship between the three major elements of human, machine, and environment in the "human-machine-environment" system, and provides theories and methods for solving human efficiency and health problems in the system.

Elbow height: refers to the distance from the ground to the bendable part of a person's forearm and upper arm.

Upright sitting height: refers to the vertical distance from the seat surface to the top of the head when a person is sitting upright.

Structural size: refers to the static body size, which is measured when the human body is in a fixed standard state.

Functional size: refers to the dynamic body size, which is the spatial range that a person can reach when performing certain functional activities. It is measured under a dynamic human state. It is the size of the range produced by the coordinated movement and rotation of the angle and the length of the limb. It is very useful for solving many problems with spatial range and position.

Racial differences: Different countries and races have very different body sizes due to differences in geographic environment, living habits, and genetic traits.

Percentile: The percentile indicates the percentage of people with a certain body size and smaller than the total number of people in the statistical object.

Normal distribution: Most of them are intermediate values, and only a small part are too large and too small. They are distributed at both ends of the range.

Height: refers to the vertical distance from the ground to the top of the head when a person's body is upright and his eyes are looking straight ahead.

Normal sitting height: refers to the vertical distance from the seat surface to the top of the head when a person relaxes while sitting.

Eye height (standing): refers to the vertical distance from the ground to the inner corner of the eye when the human body is upright and the eyes are looking forward.

Eye height: refers to the vertical distance from the inner corner of a person to the seat surface.

Shoulder height: refers to the vertical distance from the seat surface to the middle of the shoulder between the neck and acromion.

Human scale is one of the most basic data for ergonomic research.

According to the changes in the physiological state of the human body during various activities, objective and scientific measurements are made through measurement methods to analyze the energy and load of the person during the activity.

Human physiological measurement methods include:

EMG method

The state of muscle contraction during human activity is recorded with an electric current chart, so that the intensity and load of the human body can be determined quantitatively.

Energy metabolic rate method

The amount of oxygen consumption due to the energy consumed by human activities is not the same as usual

Psychometric measurement uses psychophysical measurement methods and scale methods.

Psychophysical measurement

Using physical methods, determine the minimum amount of nerve stimulation and the smallest difference in sensory stimulation.

Scale method

Dividing measures in psychology in order, such as dividing line segments on a line, and ordering comments in order

Experts or ordinary people can evaluate the beauty, ugliness, old and new, and the pros and cons accordingly.

Because ergonomics is an emerging discipline, ergonomics is indoors

The research of ergonomics has widely adopted the research methods and means of related disciplines such as human science and biological science, and also adopted some research methods of other disciplines such as systems engineering, control theory, statistics, etc. Unique new approach. Use these methods to study the following issues: measuring static and dynamic data on various parts of the human body; investigating, asking, or directly observing people's behavior and response characteristics at work; analysis and study of time and movement; measuring people before, after and during work The psychological state and the dynamic changes of various physiological indicators; observe and analyze the problems existing in the operation process and technological process; analyze the causes of errors and accidents; carry out model experiments or simulation experiments with electronic computers; use mathematical and statistical The method finds out the correlation between the variables so as to draw correct conclusions from them or develop related theories.

Common research methods are:

Observation method

In order to study the working status of humans and machines in the system, various observation methods are often used, such as analysis of workers' operation actions, functional analysis and process analysis.

2.Measurement method

The actual measurement method is a method for actual measurement with the aid of instruments and equipment. For example, measurement of human static and dynamic parameters, measurement of human physiological parameters, or measurement of system parameters and operating environment parameters.

3. Experimental method

This is a research method used when the actual measurement method is limited, and it is generally performed in the laboratory or at the job site. For example, in order to obtain data on the reading speed and error rate of various display instruments, experiments are generally performed in laboratories; in order to understand the impact of color environment on human psychology, physiology and work efficiency, long-term research is required And multiple observations to obtain more realistic data, experiments are usually performed at the job site.

4. Simulation and Model Experiment

Because machine systems are generally more complicated, simulation methods are often used in the research of man-machine systems. Simulation methods include the simulation of various technologies and devices, such as operation training simulators, mechanical models, and various human models. Through this type of simulation method, simulation experiments can be performed on certain operating systems to obtain more practical data needed for extrapolation from laboratory research. Simulators and models are often used because they are much cheaper than the real systems they simulate, but they also perform practical research.

5. Computer numerical simulation method

Because the operator in a human-machine system is a living body with a subjective will, studying the human-machine system with traditional physical simulation and model methods often cannot fully reflect the characteristics of the living body in the system, and the results must have certain errors compared with the actual ones. . In addition, as modern human-machine systems become more and more complex, using physical simulation and modeling methods to study complex human-machine systems is not only costly and has a long cycle. Once the simulation and model devices are finalized, it is difficult to modify them. For this reason, some more ideal and effective methods have been gradually developed, and the computer numerical simulation method has become a modern method of ergonomics research. Numerical simulation is the use of the mathematical model of the system to carry out simulation experiments on a computer. Researchers can simulate future systems that are still in the design stage, and analyze the functional characteristics of the three elements of the system, human, machine, and environment, and their mutual coordination, so as to predict the performance of the designed product and improve it. design. Application of numerical simulation research can greatly shorten the design cycle and reduce costs.

6. Analytical method

The analysis method is a research method adopted after obtaining certain data and data from the above-mentioned various methods. Ergonomic research often uses the following analysis methods:

(1) Instantaneous operation analysis method. The production process is generally continuous, and the transmission of information between people and machinery is also continuous. However, it is difficult to analyze this continuously transmitted information, so only intermittent analysis and measurement can be used, that is, the random sampling method in statistics is used to measure the information between the operator and the machine at each interval. , And then use statistical reasoning to sort it out, so as to obtain useful information about the human-machine environment system.

(2) Perception and motion information analysis method. There is a feedback system between human and machine, that is, the information given to the outside world is first transmitted from the sensory organ to the nerve center. After the brain processes it, it generates a reflection signal and then transmits it to the limb to operate the machine. To the operator, thus forming a feedback system. Perception and motion information analysis method is to measure and analyze this feedback system, and then use information transfer theory to explain the quantitative relationship between the information transfer between human and machine.

(3) Analysis of action load. Under the conditions of the minimum interval time required for the operation, the use of electronic computer technology is used to analyze the continuous operation of the operator, so as to estimate the load of the operator's work. In addition, by analyzing the workload of the operator during unit time, the total workload of the operator can be represented by the workload rate of the unit time.

(4) Frequency analysis method. Measurement and analysis of the use frequency of the mechanical system and the operating frequency of the operator in the home system can be used as a basis for adjusting the operator's load parameters.

(5) Crisis analysis method. The analysis of the dangers of accidents or similar accidents is particularly helpful in identifying situations that are prone to induce errors, and can also easily find problems in the system that require more complex research methods to discover.

(6) Correlation analysis method. In the analysis method, two kinds of variables are often studied, that is, independent variables and dependent variables. Correlation analysis can determine whether there is a statistical relationship between two or more variables. The statistical relationship between variables can be used to describe and predict the variables, or find out what is in line with them. For example, by performing a correlation analysis on a person's height and weight, the height parameter can be used to describe the person's weight. The development of statistics and the application of computers have made correlation analysis a common method for ergonomic research.

(7) Investigation and research method. Ergonomic experts also use a variety of survey methods to sample and analyze the opinions and suggestions of operators or users. This method includes simple interviews, specialized surveys, detailed scoring, psychological and physiological analysis and judgment, and indirect opinion and suggestion analysis.