ergonomics - the dpsa - department of public …€¦ · definition: ergonomics “the study of the...

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ERGONOMICSGETTING IT RIGHT

PRESENTED BY:

HECTOR PAREDES-TARAZONA

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DEFINITION: ERGONOMICS“THE STUDY OF THE RELATIONSHIP BETWEEN MAN AND HIS WORKING ENVIRONMENT”ERGON(work or activity)NOMOS(principle or law )

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USER CENTER DESIGN

Main principles of ergonomics:If an object, system or surrounding is intended to be used or occupied by a human being, its design must be based on the capacities, physical and mental characteristics of that user.Ergonomics is “the science that looks to adjust activities to the worker and products to the user” (Pheasant, 1996).

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ERGONOMICS

Multidisciplinary activityInvestigates all data related to people capacities and abilitiesPromotes: design of activities, products, workplaces and equipment - Proactive

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ERGONOMICS - LAWWORDLWIDE, i.e. OHSACT“REASONABLE MAN" THEORYTHE EMPLOYER SHOULD IMPLEMENT REASONABLE PRACTICAL STEPS TO ELIMINATE ANY POTENTIAL SAFETY OR HEALTH PROBLEMS IN THE WORKPLACE

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ERGONOMICS - USE

ERGONOMICS RISKDESIGN - PROACTIVE: ELIMINATE THE RISKIMPROVEMENT – REACTIVE: REDUCE / CONTROL THE RISK

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HAZARDS

1. EXCEEDING THE HUMAN BODY’S CAPABILITIES AND LIMITATIONS E.G.:

BACK PROBLEMSMUSCLE FATIGUEFORCE INJURIESREPETITIVE STRAIN INJURIES

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OFFICE WORK

Inadequate positions for long periods of time is a reason to the increasing amount of back, neck, wrist, arm and leg pain and inflammation, as well as ocular tension, among other health problems.

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MUSCULOSKELETAL DISORDERS

Long periods of time maintaining the same posture

Disadvantages of sitting posture, such as circulatory problems due to pressure on the legs

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Wear and tear on the intervertebral discs -lifting, handling and dragging loads -increased risk of back troubles.

Comparatively common in the age group 20-40, with certain occupations e.g. laborers, farmers nursing staff etc.

BACK PROBLEMS

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In Sweden, Lundgren questioned 1200 workers, and the frequency of complaints and periods of absence from work are given in the following table (EACH FIGURE IS A PERCENTAGE OF THE WORKERS QUESTIONED).

FREQUENCY OF COMPLAINTS

ABSENTEEISM

1 DAY 3 WEEKS 6 MONTHSLIGHT WORK 25.5 12.1 2.3HEAVY WORK 64.4 45.5 5.4ALL 60.0 36 4

ABSENTEEISM BECAUSE OF BACK TROUBLES

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HAZARDS

2.ENVIRONMENTAL HAZARDS, E.G.:NOISEEXTREME TEMPERATURESLIGHTVIBRATIONIONIZATIONTOXIC SUBSTANCESVENTILATION

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PRINCIPLE FEATURES OF ERGONOMIC APPROACH IN DIFFERENT WORKPLACES

1. THE HUMAN SYSTEM

BODY DIMENSIONSSTRENGTH AND STAMINAATTITUDEPERSONALITYLEVEL OF KNOWLEDGEDEGREE OF TRAINING

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2. ENVIRONMENTAL FACTORS:

LAYOUT OF WORKING AREAWORKSPACE AVAILABILITY


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MINIMUM DISTANCE

Intimate distance (0 to 45 cm)

Personal distance (45 to 125 cm)

Social distance social (1.25 to 3.5 m)

Public distance (3.5 a 7.25 m)

NEVER AT OFFICE

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WORKING AREAS

Contains working materials and equipmentNot enough space is related with inadequate positionsWorking surface height may not be the same as table height

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WORKING AREAS

Spaces and heights based on anthropometric dataShould let adjustment for specific anthropometric dimensions of each user

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3. ENVIRONMENTAL STRESSESNOISE ETC.


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4. MAN MACHINE INTERFACEPASSING OF INFORMATIONLOCATION & RELIABILITYDATA PROCESSINGSENSORY FUNCTIONCONTROLLINGTASK CHARACTERISTICSTASK DEMANDS


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5. INSTRUCTIONS AND PROCEDURESQUALITY OF BOTH VERBAL AND WRITTEN INSTRUCTIONS TO OPERATORSFORMAL WORK PROCEDURES. SHOULD BE CLEAN, UNAMBIGUOUS AND SUFFICIENT IN DETAIL.HAVE A DIRECT RELATIONSHIP WITH THE POTENTIAL FOR HUMAN ERROR.


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6. POTENTIAL STRESSESISOLATIONTIME PRESSURESTHE WORKLOADMONOTONYCONFLICTPAIN AND DISCOMFORTDISTRACTIONS SPACE ALLOCATIONSHIFT WORKINCENTIVES


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7. SOCIO-TECHNICAL FACTORS SOCIAL RELATIONSHIP BETWEEN OPERATORSHOW THEY WORK TOGETHER AS A GROUPGROUP WORKING PRACTICESMANNING LEVELSWORKING HOURS AND THE PROVISION OF MEAL AND REST BREAKS


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8. BROAD AREAS OF INFLUENCE ON ONE’S WORKPLACEWORKSTATIONWORKSPACEWORK ENVIRONMENT

PHYSICAL ENVIRONMENTPSYCHOLOGICAL ENVIRONMENT


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SYNERGISM OF RISK FACTORS IN THE WORKPLACE

THE WORKER MAY BE EXPOSED SIMULTANEOUSLY TO MORE THAN ONE ERGONOMIC OR OTHER RISK FACTOR, FOR EXAMPLE:

VIBRATIONIN CONJUNCTION WITH HEAVY MANUAL WORKPOOR POSTURE

LEADS SYNERGISTICALLY TO CUMULATIVE TRAUMA DISORDER.

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Especially with road workers using jackhammers is an important contribution to the development of muscoskeletaldisorders.Vibration consists of two parameters i.e. frequency and intensity.

VIBRATION STRESS

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Can be divided into two broad categories:1st Categories: Effects due to vibration frequency and which occurs due to body structures being activated at or near their resonant frequencies.

2nd Category: Effects due to vibration intensity which result in body parts impackting on each other.

Effects of vibration

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Tasks requiring:Repetitive, forceful or prolonged exertion of hands, frequent or heavy lifting (e.g. Agricultural lifting of maize/corn bags)Pushing of carts (e.g. Foundry workers pushing metal moulds around)Pulling or carrying heavy objects (e.g. Engineering works, mines)Prolonged awkward postures (e.g. mining, boiler shops etc).

Muscoskeletal disorders (WMSD)

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Forest workers working with chainsaws often in cold environments that may lead to White finger ( Raynaud’s syndrome).

Employees working in a small part assembly lines ( e.g. Motor vehicle assembly plant) who may contract neck tension syndrome.

OTHER DISORDERS

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Pronator (teres) syndrome-disturbance in function of the median nerve entrapment distal to the elbow. It can be confused with Carpal tunnel syndrome.Employees at risk: Electronic firms or metal works where soldering, buffing, grinding, polishing and sanding occur

OTHER DISORDERS

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Prolonged pronation of the fore arm and forced flexion of the fingers - Carpenters and mechanics are exposed.Shoulder tendonitis ( rotator cuff syndrome). Boilermakers performing overhead welding, painters performing overhead painting, electricians, construction workers.

OTHER DISORDERS

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Carpal tunnel syndrome:Incorrect work positioning. Office / administrative personnel (key borad), Video display terminal (VDT) work.Vibration, physical stress hands/wrist. Employees performing buffing, grinding, polishing, sanding, assembly work, packing, scrubbing or hammering.

OTHER DISORDERS

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De Quervain’s syndrome (inflammation around the tendons on the thumb side of the wrist). Buffing, grinding, polishing, sanding, pushing, pressing, sawing, use of pliers or small tools.

OTHER DISORDERS

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Trigger finger (or thumb) - painful or painless clicking or snapping or locking of a finger. cause pain in the palm of the hand and snapping, clicking or triggering of the involved finger.Using hand tools that have sharp edges, pressing into the tissue.Handles are too far apart for the user.

OTHER DISORDERS

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Thoracic outlet (brachial plexus compression injuries)-group of symptoms arising not only from the upper extremity, but also from the chest, neck, shoulders and head. i.e. pressure on the nerves and vessels in the thoracic outlet area. Truck drivers, material handlers, office workers and employees carrying heavy loads with extended arms may contract the disorder

OTHER DISORDERS

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ENVIRONMENTAL STRESSORS

INFLUENCING PHYSICAL AND PSYCHOLOGICAL WELL-BEING OF THE EMPLOYEES IN THEIR PARTICULAR WORKPLACES

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NOISE-may lead to noise impairment if noise levels continuously exceed 85db(A) or distract attention and effect concentration.VIBRATION may lead to White finger, Carpal tunnel syndrome etc.HEAT may lead to heatstress related disorders (e.g. heat collapse)RADIATION: Ionizing and non-ionizing


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LIGHTING glare may cause discomfort or impaired vision. Stroboscopic effects-because machinery may appear to be stationary or moving in a different manner.AIR QUALITY may lead to lung & blood disorders.

Fumes e.g. lead fumes, metal fumes etc. Gases e.g. CO gases.Spray mist e.g. paint spray, oil mist etc.Vapours e.g. volatile organic vapours e.g. paint thinners etc.Dust e.g. Pneumoconiosis.Fibers e.g. asbestos.


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WHAT HAPPENS AT THE OFFICE?

PRACTICE MAKE IT RIGHT

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CHAIRS AT OFFICEChairs may be the product most known and related to ergonomics … but ergonomics is more than just chairs

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CHAIRS AT OFFICE

Chair shapes, dimensions and range of adjustment are really important to determinate body position of the user body

Including mobility of back and legs

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CHAIRS AT OFFICE

Seated posture:

Imposes an important modification of the spine shape, that can be adopted by the human being but represent a risk while its maintained for long periods of time.

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WORKING WITH COMPUTERS

Contributes to postural problems:

Monitor located very high or very low compared to user’s eyes height (neck and shoulder problems)

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Monitor not at the front of the user (torsion of the trunk and turn of the head, represent static efforts in the back, neck and shoulders)

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No space or support for wrists and forearms while writing or using mouse can contribute to development of Carpal tunnel syndrome

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LIGHT AND GLARE

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LIGHT AND GLARE

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LIGHT AND GLARE

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LIGHT AND GLARE

GLARE

DARK

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Indirect light Block direct Sunlight

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NOISE

Usually noise levels at offices are below the considered limits of risk to cause health problems

Main problem is annoyances and interferences for conversations and to concentrate at work

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SOURCES OF NOISEPrinters (dot matrix)TelephonesCopying machinesFansPEOPLE VOICES

Try to isolate this sources and provide specific areas to talk, and adequate sound barriers between work stations

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MINIMUM SPACES FOR OFFICE (ILO 1983)

Offices with out divisions: 9 m2 / personIf office is divided: 6 m2 / personIf one person is in front to the other (with no divisions):12 m2 / person

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CONCLUSION

Ergonomics is a very broad area of study. Involve many disciplines.Studies the needs and requirements of people within a working environment.Has a great contribution to make to the health and safety of people at work, looking to increase the efficiency of all the system.

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It is concerned with the question of human capability and fallibility and the design of work equipment, in particular, with a view to eliminate the potential for human error in their different workplaces.In other words, the basic concept of ergonomics - fitting the task to the person - is a prerequisite for safe systems of work and the elimination of stress in the workplace.

CONCLUSION

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THANK YOU !!

Hector Paredes-Tarazona [email protected]

www.ighgroup.com

ergonomics - the dpsa - department of public …€¦ · definition: ergonomics “the study of the...

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