Office Ergonomics

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 Task/Processes Environment Workers Equipment/Materials

Hazard Prevention Neutral positioning Workstation design Work/rest periods Task rotation Exercise

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 Elements Good Working Positions Work Process Workstation Environment Workstation Components

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. Good Working Postures

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

Chairs Need to be adjustable in many different directions • Height • Tilt of seat pan • Angle of back • Provide lumbar support • Adjustable arms • Capacity, seat width

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 Ergonomic Chairs Small Seat Minimal Contour Seat Height: 16.5" - 21.5"Backrest: 19.5"W x 22.5"HSeat Size: 19"W x 17"D

Chair Specifications Chair Specifications Seat HeightBackrestSeat Size Seat HeightBackrestSeat Size 18" - 23"24"W x 26"H26"W x 21"D 16.5" - 21.5"19.5"W x 22.5"H22.5"W x 17"D Ergonomic Chairs Deep Contoured Seat, Knee Tilt Available Big & 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 & Distance Design & 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 Placement Pointer 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 Considerations

Work/rest periods An element of a good prevention 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 & Breaks Some 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

Eye Strain A 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

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

Office Ergonomics