occupational safety health (osha)

WORKPLACE

ENVIROMENT AND

ERGONOMICS

ERGONOMICS

WHAT IS ERGONOMICS??? Ergonomics is the study of fitting the

work/job to the individual. Ergonomics matches the design of tools, controls, and equipment to fit the safety needs of the operator. Since each of us has different needs, ergonomic design of tools, equipment, and workspaces must be adjustable enough to accommodate a varied range of body types.

INTRODUCTION Derived from two Greek works: “Nomoi” meaning natural laws “Ergon” meaning work Ergonomics addresses the relationship

between people , their tasks , equipment and work environment

Hence , ergonomists study human capabilities in relationship to work demands…

HISTORY OF ERGONOMICS In 1857,Wojciech Jastrzebowski created

the word “ergonomics” in a narrative he wrote about the science of nature.

World war ll in 1943, an army officer Alphonse Chapanis, learned that if the control layout in the cock pits of plane were simplified, the pilot make fewer errors.

HISTORY OF ERGONOMICS (CONT’D) After world war ll, ergonomics not only

productivity, but also the safety of the workers.

Research take place in various area The affect of heavy labor on the heart;

the maximum loads that should be pulled , pushed or carried

The amount of muscle force that should be required to perform

WORKSTATION DESIGN

PRINCIPLE

GENERAL ERGONOMICS PRINCIPLE FOR WORKSTATION DESIGN Work surface Sit or stand? Fitting all the pieces

together Accepted postured Sitting basics Work surface basics Keyboard / mouse

basic

Alternative input devices

Monitor basic Telephone basic Source documents Additional

accessories Work/rest schedule

WORK SURFACEHEIGHT May very depending on task ; e.g surface

higher for writing and typing Should not contact the thighs or kneesWidth Wide enough to accommodate all needed

input devices, task materials and accessories Enough clearance for legs and any items

stored below work surface

WORK SURFACE…CONT’DDepth Allow for allow positioning of monitor Allow for postural changes Knees should not contact items /

support structure under work surface

SIT OR STAND?Sit when Doing fine manipulated Need high visual attention Need high degree of stability Precise foot control is needed There is not heavy material handling Task requires fixed postured for

extended periods

SIT OR STAND?....CONT’D Frequently handle heavy objects or

when experience heavy downward forces

Mobility is required Frequently need to make extended

reaches Doing a variety of tasks Doing work intermittent work Have low back pain

FITTING ALL THE PIECES TOGETHER Seating Work surface Keyboard Monitor Telephone Additional accessories Work/ rest schedule Manual material handling

ACCEPTED POSTURESUpright ThighsReclinedStandingMove throughout these postures

SITTING BACISHips slightly higher than kneesFeet supported Lumber support below beltlineBack angle upright or slightly reclinedArms relaxed or supported

WORK SURFACE BASIC Design must be based on job tasks Surfaces should be height adjustable Reading/ writing surface 2 inches higher

than elbow height Keyboard / mouse surface elbow height

KEYBOARD / MOUSE BASICS At or slightly lower than elbow height Neutral wrist postures Relax shoulders Use a light touch

ALTERNATIVE INPUT DEVICES Split keyboard design Vertical or concave keyboard design Trackball Touchpad Mouse with a supinated angle Always use on a trial basis prior to

purchase

MONITOR BASICS25 – 36 inches from eyesAt or slightly lower than eye levelDirect alignment Avoid glare or contrast from bright light sources

ADDITIONAL MONITOR BASICS Ambient light levels 20-50 foot candles Refresh rate 70-80 Hz Dark characters on a light background Clean monitor at least 1x per week

TELEPHONE BASICS Avoid cradling the hand set between

your shoulder and head Hold the hand set with your dominate

hand Use a headset or speaker phone when

appropriate

SOURCES DOCUMENTS Document holder -adjacent to monitor -between monitor and monitor Reading / writing slope

ADDITONAL ACCESSORIES Large grip pen/pencil -decrease stress on muscles/tendons Wrist rest -Use only while pausing between key

strokes Footrest -essential when feet do not touch the

floor -help promote postural changes

WORK/REST SCHEDULE Rotate job tasks at least 1x per hour Utilize schedule breaks Incorporate stretching into daily routine Change postures frequently Get out of your chair

WORK/REST SCHEDULE Rotate job tasks at least 1x per hour Utilize schedule breaks Incorporate stretching into daily routine Change postures frequently Get out of your chair

ERGONOMICS RISK Forceful exertions Repetitive motions Awkward postures Static postures Compression or contact stress Lighting Vibration Noise Cold temperatures

FORCEFUL EXERTIONS Forceful muscular exertions place high

loads on the muscles, tendons, joints, and discs, and so are associated with most musculoskeletal disorders.

Increased muscular exertion results in the increase of muscles fatigue.

With increased muscle fatigue, time needed to recover increases. If recovery time is limited, soft tissue injury is more likely to occur.

REPETITIVE MOTIONS Repetitive Motion Injuries (RMI, also

known as RSI, CTD, CTS) are a class of injuries and illnesses that result from weeks, months, or years of overuse of human joints.

Connective tissues can become sore and sometimes unusable from repeated exposure to micro-trauma.

Because of the slow onset of symptoms, people sometimes ignore the condition until the symptoms become chronic and permanent injury occurs.

AWKWARD POSTURES Awkward postures refer to positions of

the body (limbs, joints, back) that deviate significantly from the neutral position while job tasks are being performed.

For example, when a person's arm is hanging straight down (perpendicular to the ground) with the elbow close to the body, the shoulder is said to be in a neutral position.

AWKWARD POSTURES (CONT’D) When employees are performing

overhead work such as installing or repairing equipment or grasping objects from a high shelf, their shoulders are far from the neutral position.

STATIC POSTURES "Static work" refers to the

musculoskeletal effort required to hold a certain position, even a comfortable one.

For example, when we sit and work at computers, keeping our head and torso upright requires either small or great amounts of static effort depending upon the body positions we choose.

CONTACT STRESS Contact stress results from occasional,

repeated, or continuous contact between sensitive body tissue and a hard or sharp object.

Contact stress commonly affects the soft tissue on the fingers, palms, forearms, thighs, shins and feet.

LIGHTING Lighting that is not appropriate for work

task is a major factor in visual discomforts such as eyestrain, burning or itchy eyes, headaches and blurred or double vision.

VIBRATION Vibration restricts the blood supply to

the hands and fingers, which, depending on the vibration level and duration of exposure, can contribute to an ergonomic injury.

Signs and symptoms of vibration-induced injury, such as Reynaud's phenomenon, start with occasional numbness or loss of colour in the fingertips.

NOISE Noise is an often overlooked part of the

working environment. Office machines, phones, and

coworkers' conversations can be a distraction.

COLD TEMPERATURES Cold temperatures reduce the natural

elasticity of the body and reduce the sensation of touch (tactile feedback).

In order to get the same amount of tactile feedback, an employee may exert more force than is necessary.

WORKPLACE ENVIRONMENT

5S

WHAT IS 5S?? There are 5 primary phases of 5S:

sorting, straightening, systematic cleaning, standardizing, and sustaining. Additionally, there are three other phases sometimes included; safety, security, and satisfaction.

SORTING (SEIRI) Eliminate all unnecessary tools, parts,

and instructions. Go through all tools, materials, and so

forth in the plant and work area.

STABILIZING OR STRAIGHTENING OUT (SEITON)

The place for each item should be clearly labeled or demarcated.

Items should be arranged in a manner that promotes efficient work flow, with equipment used most often being the most easily accessible.

SWEEPING OR SHINING (SEISO) Clean the workspace and all equipment,

and keep it clean, tidy and organized. At the end of each shift, clean the work

area and be sure everything is restored to its place.

STANDARDIZING (SEIKETSU) All work stations for a particular job

should be identical. All employees doing the same job

should be able to work in any station with the same tools that are in the same location in every station.

SUSTAINING THE PRACTICE (SHITSUKE)

Maintain focus on this new way and do not allow a gradual decline back to the old ways.

While thinking about the new way, also be thinking about yet better ways.

APPERECIATE THE PROPER AND SAFE

METHOD OF ERGONOMICS IN THE

WORKPLACE

SAFE METHOD

THANK YOU