Office Ergonomics. Office Work & Human/Computer Interactions Work station design Posture...

Office Ergonomics

Office Work & Human/Computer

Interactions

Work station design Posture Keyboards Software/human interactions Human Behavior

Office Work & Human/Computer

Interactions

Early studies 1980’s Eye problems Shoulder problems Lower back problems Neck strain Hand & wrist problems

Office Work & Human/Computer

Interactions

1991 study of 420 medical secretaries 63 % reported neck/shoulder pain

51% low back pain

30 % hand/wrist pain

15 % elbow pain

Who’s At Risk?

Nearly everyone, but women report more incidents of discomfort

Low motivation

Poor workstation design

Many short term studies, few long term or independent studies.

Are some people at greater risk than others?

Some researchers think so….

Studies quoted on Cornell’s ergo web site link repetitive motion injuries to…

Working with the wrists in deviated postures for any reason: causes compression of the median nerve

Static postures, especially using a pinch grip to hold something in place

Some studies have shown greater risks for people who

are… Pregnant

Obese

Lack general physical capabilities, such as strength

People who feel as if they lack control over work pace, environment, and communication

Prevention is crucial to Cost Containment

Evaluate all contributing factors=

Hazard Identification

EnvironmentEnvironment

WorkersWorkers Equipment/MaterialsEquipment/Materials

Task/ProcessesTask/Processes

Hazard Prevention

Neutral positioningWorkstation designWork/rest periods

Task rotationExercise

What is neutral positioning?

Non-stressed postures Relaxed, right angles at

Knees, hips and elbows Wrists straight rather than flexed (down) or

extended (up) Lower and upper back supported

Computer Workstations

Key ElementsKey Elements

Good Working PositionsGood Working Positions

Work ProcessWork Process

Workstation EnvironmentWorkstation Environment

Workstation ComponentsWorkstation Components

Good Working Postures

•Hands, wrists, and forearms are straight, in-line and roughly parallel to the floor.

•Head is level, or bent slightly forward, forward facing, and balanced. Generally it is in-line with the torso.

•Shoulders are relaxed and upper arms hang normally at the side of the body.

•Elbows stay in close to the body and are bent between 90 and 120 degrees.

•Feet are fully supported by floor or footrest.

•Back is fully supported with appropriate lumbar support when sitting vertical or leaning back slightly.

•Thighs and hips are supported by a well-padded seat and generally parallel to the floor.

•Knees are about the same height as the hips with the feet slightly forward.

Work Process

Task Organization Impacts repetition Prolonged periods of activity Medical awareness & training

Work Environment

Lighting Glare Ventilation Noise

Workstation Design

Chairs Monitors Keyboards Pointer/Mouse Wrist/Palm Support Document Holders Desks Telephones Footrests

Elements of good work station design

Adjustable chairs Keyboard height and angle

Avoid sharp edges

Monitor height and angle Glare, poor contrast, etc. are risk factors

Chairs

Ideas about correct posture go back to 1884 Upright vs. backward leaning, pressure on

disks, lower back Chair provides support for upper and lower

back

Need to be adjustable in many different directions

Height Tilt of seat pan Angle of back Provide lumbar support Adjustable arms Capacity, seat width

Chairs

Ergonomic Chairs

Chair Specifications                            Seat

HeightBackrestSeat Size

10 Standard Adjustments

•Pneumatic Seat Height•Seat Angle or Tilt •Seat Angle Tension Control •Backrest Angle •Backrest Height•Backrest Depth •Inflatable Lumbar•Armrest Height•Armrest Rotation/Swivel•Armrest Width

Small Seat

Minimal Contour

Seat Height: 16.5" - 21.5"Backrest: 19.5"W x 22.5"HSeat Size: 19"W x 17"D

Ergonomic Chairs

Chair Specifications

Seat HeightBackrestSeat Size

18" - 23"24"W x 26"H26"W x 21"D

Chair Specifications

Seat HeightBackrestSeat Size

16.5" - 21.5"19.5"W x 22.5"H22.5"W x 17"DDeep Contoured Seat, Knee

Tilt AvailableBig & Tall

Monitors

Viewing Distance: 20”-40” Viewing Angle: 15-20 degrees

below horizontal

Viewing Time Viewing Clarity

Keyboards

The objective is to keep the hands and wrists in as “neutral” a position as possible

Adjustments, may include tilting or not tilting the keyboard, wrist rests in front of the keyboard, and repositioning the entire body

Alternative shapes of keyboards may help: Split Tented/Angled Negative Slope Supportive Scooped Keep in mind

Keyboard Placement – Height & DistanceDesign & Use

Pointer/Mouse Interactions

For CAD operators Thumb and forefinger problems Change kind of mouse

Thumb joint pain, switch to “Uniball” or three-finger mouse

Keep in mind

Pointer PlacementPointer Size, Shape, & Settings

Wrist/Palm Supports

In general, research supports the idea of resting the hands on some kind of a surface during keying pauses.

The use of wrist rests has been associated with reduced muscle activity in the arms and shoulders, straighter wrist postures, comfort, and preference.

Wrist/Palm Supports

Some research suggests that wrist rest users sit in a somewhat more reclined posture than people without wrist rests, which is known to be comfortable and healthy for the back

However, wrist rests are not without potential problems

Caution

Wrist/Palm Supports

Not all studies of wrist rests show positive effects

Use of wrist rest causes the fluid pressure in the carpal tunnel to rise, sometimes significantly

Use of convex wrist rests, which concentrate pressure in a small area, are less desirable than broad, flat ones

Benign cysts apparently have been caused by constant pressure on the wrist

Typists should use them during keying pauses, not during keying, in order to have free hand and arm movement and to reduce the amount of time the wrist is compressed

Document Holder

Are designed to minimize eye and neck movement by keeping your documents at the proper viewing level

Desks

Work Surface Depth Location of Frequently Used Devices Should be

Located in Repetitive Access Zone

        Recommended Zones for Workplace Components

Telephones

Head sets can help avoid neck and shoulder strain for telephone use.

Footrests

Reduces leg strain and promotes circulation

Reduces strain on lower back Should position your knees to roughly a

90 degree angle

Other ConsiderationsOther Considerations

Work/rest periods

An element of a good An element of a good prevention strategyprevention strategy

Provide regular breaks by inserting a different kind of task into the routine

Some studies recommend 5 minutes of rest per hour of typing

Other studies recommend 15 minutes of rest per four hours of work.

Task Rotation

Alternate other kinds of office tasks, such as filing, copying

Caution: May be just as repetitive as typing and use the same motions and muscles

However, more productive and feel less like an interruption than “just a break

Task Rotation & BreaksSome companies have actually installed software that “shuts down” the system for regular breaks

Other companies have organized or signaled breaks

These can be aggravating, as they interrupt a task in progress

Eye Strain

Eyestrain is the most common complaint from computer users

Intensive use Software Interactions

Inadequate or detrimental lighting and monitor conditions Distance to monitor Ambient lighting Glare

Pre-existing eye conditions, including those you may not be aware of

Stress

A study conducted by Cornell UniversityA study conducted by Cornell University

Showed that there was an increase in the number of cases of repetitive stress injuries after new and

hard to use software was introduced

Especially if there were multiple screens or fields on the monitor simultaneously

Eye Strain

Prevention Task rotation Get a professional eye examination Control the lights & the monitor

Enough light on documents Eliminate glare

Rearrange the workstation Anti-glare screen

Eye Strain

Solving Office Ergonomic Problems

Evaluate non-work stressors Evaluate work stressors

Use checklists Use workers’ compensation claim data Use personal interviews/discomfort surveys Conduct job safety analysis

Observation Measurements

Implement solutions Provide Employee Training

Analyze a problem jobThink about the role behavior plays in ensuring proper use and comfort.

A claim of “ergonomic design” will not ensure improved use or comfort, (or reduced risk factors) if behaviors have been ignored

For instance, if workers will not use the new tool, it cannot reduce the risk

Questions?Questions?