ERGONOMICS ERGONOMICS IN WORKPLACEIN WORKPLACE

Introduction• Accident are basically due to human error and in

most instance can be attributed to the poor ergonomics.

• Unsafe act and unsafe condition contribute to accidents.

• Responsibility of management to address this gap• Employees have varying capabilities and

limitations in strength, speed, flexibility and skills.• These factors must be considered when

designing the workplace.

History• The term ergonomics, from Greek ergon, meaning "work",

and nomos, meaning "natural laws", (The Outline of Ergonomics, i.e. Science of Work, Based on the Truths Taken from t

• Found by Ancient Greece in the 5th century BC in the design of their tools, jobs, and workplaces. Example of this can be found in the description Hippocrates gave of how a surgeon's workplace should be designed and how the tools he uses should be arranged. Egyptians Dynasties made tools, household equipment, among others that illustrated ergonomic principles.

• World War II marked the development of new and complex machines and weaponry, and these made new demands on operators' cognition.

Objective • Ergonomics describes the interaction between the

operator (employee) and task demands.• Objectives

To reduce unnecessary stress. Focuses on how work effect people.Emphasis/important to reduce fatigue on employees by

designing tasks within people’s work capabilities.• Goal :

To achieve the optimal match between employees and the overall work environment.

Focus is on suitability of the task, system or equipment for the employee.

Definition

• The science of making things comfortable and efficient for the human performance.

• Ergonomics is the study of designing equipment and devices that fit the human body, its movements, and its cognitive abilities.

• Physiological basis of workSeated WorkStanding Work

Seated Work

• Health hazardContinuous sitting a common source of discomfort and fatigue.

• Control measuresArrange work in a semi-circle.Uses a swivel chair to reduce body twisting, to allow

easy movements, and to reduce side to side motions,Uses sloping work tables whenever possible to reduce

bending, and to encourage an upright position.

Semi-Circular Workstation

Standing Work

• A person’s body affected by arrangement of work area and tasks while standing.

• Employee less freedom to and rest muscles which contributes to health problems such discomfort and severe health problems.

• These occurs when job is designed without considering job characteristic of the human body.

Standing Work• Health hazard

can lead to blood to pool in the legs and feet and can result in inflammation of veins.

Standing over the period cause joint in the spine, hips, knees, and feet to become temporarily immobilized or locked

• Control measureControl/tools be within reach of employee without

twisting or bending.For work requires standing only, a seat be provided to

allow the worker to sit occasionally.

Work allows operation be within easy reach

MSD (Muscular Skeletal Disorders)

• The term MSD covers any injury, damage or disorder of the joints or other tissues in the upper/lower limbs or the back.

• Some common examples of musculoskeletal disorders are: – Vibration White Finger – Shin Splints – Scoliosis

What is Vibration White Finger? • Vibration White Finger is a repetitive stress injury

where the small blood vessels in the fingers periodically spasm. The spams cause constriction of the blood supply to the fingertips turning the fingers white. Soon after, the available oxygen in the blood is used up and the fingers turn blue. Once the spasms subside the fingers turn red as oxygenated blood returns to the finger tips.

What are shin splints?The term shin splints is a common misnomer in sports medicine. It does not imply a specific diagnosis, rather it is the symptom of pain over the front of the tibia bone. The pain from shin splints can be due to either problems of the muscles, the bone, or the attachment of the muscle to the bone. Therefore, 'shin splints' is simply the name given to pain over the front of the lower leg.

Indoor air quality (IAQ)• is a term referring to the air quality within and

around buildings and structures, especially as it relates to the health and comfort of building occupants.

• IAQ can be affected by microbial contaminants (mold, bacteria), gases (including carbon monoxide, radon, volatile organic compounds), particulates, or any mass or energy stressor that can induce adverse health conditions.

• Indoor air is becoming an increasingly more concerning health hazard than outdoor air. Using ventilation to dilute/reduce contaminants, filtration, and source control are the primary methods for improving indoor air quality in most buildings.

Lighting and Sightedness

Lumens“Lumen” is the unit of total light output from a light

source. If a lamp or fixture were surrounded by a transparent bubble, the total rate of light flow through the bubble is measured in lumens. Lumens indicate a rate of energy flow. Thus, it is a power unit, like the watt or horsepower.

Typical indoor lamps have light outputs ranging from 50 to 10,000 lumens. You use lumens to order most types of lamps, to compare lamp outputs, and to calculate lamp energy efficiencies (which are expressed as lumens per watt).

Footcandles and Lux“Footcandles” and “lux” are units that indicate the density of light that falls on a surface. This is what light meters measure. For example, average indoor lighting ranges from 100 to 1,000 lux, and average outdoor sunlight is about 50,000 lux. The official unit of candlepower is the“candela,”

BrightnessIn general, “brightness” is an expression of the amount of light emitted from a surface per unit of area. “Brightness” is not an official term of the lighting trade, However, the concept is essential for understanding visual quality, especially in relation to contrast and glare.

Fig. 1 Footcandle meter The meter is used to measure“illuminance.” It is the only measuring instrument that youneed for most applied lighting efficiency work. Being an oldermodel, this meter indicates in units of footcandles. Newermodels indicate in units of lux.

In Summary ...So, here is the overall picture. A lamp produces a

certain amount of light, measured in lumens. This light falls on surfaces with a density that is measured in footcandles or lux. A person looking at the scene sees different areas of his visual field in terms of levels of brightness, or luminance, measured in candelas per square meter.

Many characteristics other than light intensity are important in selecting light sources. These include color, operating temperature, starting time, etc.

Temperature and Humidity

Human comfortHumans control their body temperature mainly

by sweating and shivering. The United States Environmental Protection Agency cites the ASHRAE Standard 55-1992, Thermal Environmental Conditions for Human Occupancy, which recommends keeping relative humidity between 30% and 60%. At high humidity, sweating is less effective, and we feel hotter. At low humidity, the risk for nosebleeds increases, especially during cold winter seasons.

Some people experience difficulty breathing in high humidity environments. Some cases may possibly be related to respiratory conditions such as asthma, while others may be the product of anxiety. Sufferers will often hyperventilate in response, causing sensations of numbness, faintness, and loss of concentration, among others.

Air conditioning works by reducing humidity in summer. In winter, heating cold outdoor air can decrease relative humidity levels indoor to below 30%, leading to discomfort such as dry skin and excessive thirst.

Sound and Hearing Quality• Sound quality is the quality of the audio output from

various electronic devices. Sound quality can be defined as the degree of accuracy with which a device records or emits the original sound waves. Sound quality is also the physical pleasure or fatigue experienced by a listener.

• The frequency range of sound (in hertz) which the equipment is capable of sampling affects sound quality. Humans can hear frequencies ranging from about 20 Hz to approximately 20 kHz.

NoiseEmployers must use feasible engineering or administrative controls to reduce exposures whenever the levels in Table 3 are exceeded. Employers must also issue hearing protectors and employees must wear them when overexposed. Table 3

Noise level measurement equipment

Ear Muff & Ear Plug