MODULE: INTRODUCTION TO ERGONOMICS

WHAT IS ERGONOMICS?

Ergonomics is the science of fitting workplace conditions and job demands to the capabilities of the working population (interaction between the operator and the job demands).

Ergonomics provides the guiding principles and specifications according to which tools, machines, work procedures and workplaces are designed for safe use. The efficiency of a machine depends on the ability of the worker to control it effectively and accurately. The fact that workers are able to operate in poorly designed workplaces does not mean that this is the most efficient method of production; workers should be able to operate machines in the least stressful way.

Ergonomic deficiencies in the workplace may not result in immediate body pain but over time the body’s ability to adapt fails resulting in musculoskeletal disorders. Ergonomics should be seen not as finding problems but rather as giving solutions to the problems and can be applied to any industry.

WHAT ARE WORK-RELATED MUSCULOSKELETAL DISORDERS (WMSDS)?

Work-related musculoskeletal disorder, is a term used to denote those musculoskeletal disorders for which there is epidemiological evidence that workplace factors (for example, force, repetition, and vibration) increase the probability for the occurrence of the disorder.

• Mechanical stresses of the tissues over a prolonged period; can result in disorders of the muscles, nerves, tendons, ligaments, joints.
• WMSDs are not the result of an acute injury but have a chronic onset developing over periods of weeks, months or even years and are often multi-factorial in origin.
• If not detected and treated early, recovery may require weeks, months and years and in some cases, may become chronic.
• The nature of the physical stress and the body region enduring the load for the most part will determine the affected area and the type of injury.
• Examples of work place ergonomic risk factors include repetitive, forceful or prolonged exertions such as frequent heavy lifting, pushing, pulling, or carrying of heavy objects, prolonged awkward postures. Vibration and cold may add risk to these work conditions. Jobs that present multiple risk factors will have a higher probability of causing musculoskeletal problems. The level of risk depends on the intensity, frequency and duration of the exposure to these conditions.

The human body is continuously required to perform physical work. Physical stresses include moving of the body, moving objects and maintaining body posture. The response of the body to the physical stress is described as strain and is influenced by the capacity of the individual and by the demands placed on it.

GOAL OF ERGONOMICS:

The goal of ergonomics is to optimize the relationships between the worker, the task and the environment, in a cost effective manner, by modifying people’s work to be within their capabilities. This will result in a decreased risk of injury and illness, improved job performance and quality of work, in addition to improving the well-being of the organization due to decreased operating costs, stable workforce and improved morale.

A task is accomplished by the interaction of the employee and the machine in a particular workspace, which is contained in a particular environment. The workspace is described in terms of its size and the layout of the equipment/machinery. These two factors will have an effect on the posture of the worker and the reach distances, and with a resultant effect on comfort and efficiency. The environment is described in terms of its temperature, lighting, noise and vibration.

General Introduction to Occupational Health: Occupational Hygiene, Epidemiology & Biostatistics by Prof Jonny Myers is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.5 South Africa License