SEMINAR ON ERGONOMICS By:- ATINDER PAL SINGH

 The concept of ergonomics helps to study the effect of health and safety i.e. working environment on productivity.  The worker interest in a job to a greater extent depend on how comfortable and safe the workplace is. A number of factors are need to be considered while designing the workplace and the science which considers these factors is called “ERGONOMICS”. Thus ergonomics is the science which deals with the relationship between man and his working environment.

 The word ergonomics is derived from the Greek word “Ergo” which means work, and “Nomo's” means natural laws. Therefore,ergonomics means laws of work.  Ergonomics is the science of work which deals with relationship between man and his working environment.  Ergonomics is the process of designing or arranging work places, products and system so that they fit the people who use them.  Ergonomics can also be defined as the study of physiological and psychological aspects of human being.

 To improve human well being through attainment of optimal working conditions.  It attempts to minimize the risk of injury, illness, accident and errors without compromising productivity.  To enhance man-machine relationship.  To improve the design of machine at initial stage or also the modification of existing products.

.. THE TOOL THE TASK THE WORK STATION AND ENVIRONMENT THE USER/OPERATOR

ANTHROPOLOGY- It is the study of the variation of human charactericts such as height, weight, reach, ratio of leg to shoulder length etc. such variations between the individual and sexes are noted and mean value is determined. PSYCHOLOGY- This is the study concerned with human behaviour and human reaction under various working conditions. Ergonomics are aimed at eliminating human drudgery and eliminate factors which make job uncomfortable.

 PHYSIOLOGY- Physiology is concerned with determination of: 1.the human stamina; 2.The speed, accuracy, and force with which body movements can be carried out. studies have revealed that knowledge of all these factors helps job or machine to be designed so that heavy work is done by big muscle, and light work by smaller ones,

 A man-machine system(MMS) may be defined as combination of man and some machines to bring about the desired output from given input. Examples : 1.a man with a hammer. 2. a typist with a typewriter. CLASSIFICATION OF MMS- 1. CLOSED LOOP SYSTEM- A closed loop system is continous one in which some process is performed that requires a continous feedback. E.g-1. a driver driving a car 2. a worker on lathe.

 Fig. - close loop system  2. OPEN LOOP SYSTEM- An open loop system is one which, when started needs no further control or atleast cannot be further controlled. There is no feedback in open loop. CONTROL MANMACHINE DISPLAY

1. Design of visual display - a. Should be as simple as possible. b. Convey only important information. c. Preferred in noisy conditions. 2. Design of work place- The workplace must accommodate materials, tools, machines and auxilary services to perform specified task. 3. Design of controls-It is used to transmit information to some system.

IMPORTANT ASPECTS OF MMS 1.BUTTON- For rapid selection between alternatives. 2.TOGGLE- For definite used action involving two choices. 3.SELECTOR- For more than two and less than ten choices. 4.KNOB- For continuous variable. 5.LEVER- For a definite activity 6.WHEEL- For precise activity involving large angles of rotation.

 4. Working conditions- Factors affecting comfort of worker and his efficiency are : a. lightning b. noise c. ventilation d. temperature.

 It is the branch of ergonomics that deals with body shape and size. It studies the measurment of human body such as linear dimension, weight, range of movements etc.   Anthropometry data is useful in designing workstation to the operators dimension.  The measurment of body fall in two classes: 1. structural body dimension- These are measured with the body of person in fixed position. These measurment can have specific application like designing earphones, wrist watches etc.  2. Functional body dimension- These measurments are taken of body position which are in state of motion. These dimensions are used widely for design problem as in case of people in motion. Such as operating a machine, reaching across table for tools etc. 

 Working in awkward postures  Prolonged sitting and standing  Bending, reaching, stretching  Driving for extended periods of time  Heavy lifting  Awkward lifting  Lifting in combination with twisting  Pushing, pulling, carrying  Accidents, slips, trips, falls

 Musculoskeletal Disorders (MSD)  MSDs are injuries and illnesses that affect muscles, nerves, tendons, ligaments, joints or spinal discs.

 1. SWELLING  2.LOSS OF FUNCTION  3. CRAMPING  4. LOSS OF BALANCE  5. DECREASED GRIP  STRENGTH  6.DECREASED RANGE OF  MOTION 1. MUSCLE FATIGUE 2. NUMBNESS 3. TINGLING 4. STIFFNESS 5. BURNING SENSATION

 1. TENDONITIS- An inflammation of the tendon. Typically occurs in the shoulder,wrist, hands, or elbow,  2. CARPAL TUNNEL SYNDROME- Irritation of the median nerve, which runs through a bony channel in the wrist called the carpal tunnel. Usually results from twisting of the wrist.

 3. EYE STRAIN - The eyes become strained as a result of poor lighting, glare or viewing from awkward positions.  4. MUSCLE STRAIN – Pain in muscles.  5. HAND/ARM VIBRATION SYNDROME- Tingling, numbness, blanching, loss of dexterity in the hand/arm

 INDUSTRIAL ENGINEERING – M.MAHAJAN  ERGONOMICS FOR BEGINEERS- JAN DUL