Office Ergonomics

Ergonomic Guidelines for Computer UsersFrank Gonzales, CEES, CEAS

Ergonomics Program Services

What other services are provided?

– Training sessions

Office, Industrial (can be specific to dept/job/task)

– Job Site Analysis (JSA’s)/Ergonomic Evaluations

Individuals

Groups (tasks, jobs)

– Written Documentation

Reports (problems, recommendations, etc)

– Equipment Loans

Computer Equipment, mats, knee pads, gloves, etc (as available)

When have you used

Ergonomics?

The following recommendations focus on ergonomic

issues common to computer users. EHS offers guidelines on

how to adjust your furniture, computer equipment, and work

aids; to organize your work area and tasks; and to

incorporate change and movement into your daily routine.

When improving your workstation setup,

keep in mind that changes may feel

unusual or awkward at first. It may

take a few days before they feel

natural.

Ergonomics

Designing the job to fit the

worker, not forcing the

worker to fit the job.“

Make physically

demanding job tasks as

easy on the body as

possible!

Fewer Injuries

Increased Productivity

Increased Efficiency

Improved Quality of work

Improved Employee attitude

Lower employee turnover

Makes the job easier

How Ergonomics Helps

Benefits of Ergonomics

2008 Liberty Mutual Workplace Safety Index

The estimated direct workers’ compensation costs in the United

States for the most disabling workplace injuries and illnesses in

2006 were $48.6 billion

Ergoweb estimates the total cost for ergonomics-related injuries at

$30.9 billion!! (63.6% of total disabling injuries)

– Direct cost of worker's compensation claims.

Indirect costs…… estimated 2 – 5 times the direct costs. Estimate of

true cost to USA business at $61.8 to $154.5 billion.

Office ErgonomicsIt could be worse

What is the problem?

Work related injuries

– Musculoskeletal

Disorders (MSD)

(Also called):

Cumulative Trauma

Disorders

– (Occur over time)

Repetitive Strain injury

(Repetitive motion)

– Accidents

Slips, trips and falls

Cuts

How Injuries Occur

Static Muscle Contraction

Muscles Tense

Blood Flow is reduced

Muscle Nutrition is reduced

Waste products (lactic acid) build up

Muscle pain and fatigue

Injury/Disability

Other

Common

Office

Injuries

MSD’s: Definition

An MSD is an injury to the

muscles, ligaments,

tendons, joints, cartilage,

bones, spinal discs, nerves,

blood vessels etc. (soft

tissues)

These can occur in any part

of the body

Common MSD’s

Tendonitis

Bursitis

Tenosynovitis

Epicondylitis

– Tennis Elbow

– Golfers Elbow

Carpal Tunnel

Syndrome

Trigger Finger

Back Strain

Neck Strain

Herniated Discs

Thoracic Outlet

Shoulder Impingement

Cubital Tunnel

Syndrome

MSD Signs and Symptoms

Fatigue

Aches and Pain

Weakness

Stiffness

Discomfort

Numbness

Burning

Tingling

Swelling

Body parts “Falling

asleep”

IF YOU HAVE AN INJURY…

Report the problem to your supervisor

– Recognize the signs & symptoms (Do NOT ignore

them!)

– Report signs and symptoms EARLY!!

– Contact Ergonomics Program Staff

File appropriate paperwork

See a qualified physician

Contact Workers’ Compensation Department

with any questions

OTHER RISK FACTORS for

MSD’s Contact Stress

Cold/heat

Vibration

Noise

Physical Stress

Emotional Stress

Etc

Risk Factors

These risk factors just mentioned are things

we need to try and avoid.

The more risk factors involved in daily

activity the higher the risk increases.

How to avoid risk factors?

– Achieving neutral posture and following other

guidelines and tips which are in place for your

protection.

FORCE

Forceful exertions increase the risk of

developing MSDs.

– Example: Striking the keys on a keyboard with

excessive force, repeatedly may result in

soreness in the fingers and forearm.

Excessive Force

REPETITION

Too much repetition or too little movement

can result in MSDs.

– Example: Using an input device (mouse)

steadily for several hours may result in

significant fatigue in the hand & forearm.

AWKWARD POSTURE

Awkward posture, especially if associated

with force & repetition, can increase the

risk of developing an MSD.

– Example: Looking down at a small laptop

screen with your neck bent all day, can lead to

stiff neck and headaches.

CONTACT STRESS

Contact Stress can increase the risk of

developing an MSD.

– Example: Leaning against the hard edge of a

desk can reduce blood flow to the hands and

lead to injury.

INSUFFICIENT RECOVERY

EXTENDED DURATION

Biggest problem

Avoid 10-12 hour work days!

Perfect setup will still not prevent injury if

body does not have a chance to recover.

With an increased work load, the body

needs time to recover or injury may result.

Recovery

GET UP!!– Get away from the computer

– This is one of the biggest factors in

office ergonomics

– Don’t be a robot

Use your chair – Move!

Future Workstation?

Variety & Movement

Chairs

Keyboard & Mouse

Wrist/Mouse Rests

Computer Monitor

Vision

Phone

Copy Holders

topics

CHAIRS!

Your Chair

Which one pair should

be used for a marathon?

Find the chair that

works for you

Use dynamic sitting

postures (MOVE)

Like your shoes….need

the right fit and type

Proper Chair Position

Feet flat on the floor

Knees and hips in 90 degree angles

– (to start)

Sitting back in chair

2-4 inches from edge of chair to back of knee

Lumbar support near belt line (slightly higher)

Shoulders and upper back relaxed

What is the proper way to sit?

There is NO such thing as a perfect sitting position.

The best position (reduced forces on the lower back) is either a declined or reclined position– Technically the best posture for the back (reduced forces)

is STANDING!

The best sitting posture is the NEXT posture.

DO NOT SIT IN ONE POSITION FOR EXTENDED DURATIONS!! – (Change positions periodically)

Remember Try to adjust your chair

first. Then adjust your keyboard, mouse, etc

There is no perfect sitting position.

Varying your posture can help.

Make adjustments throughout the day but remember to keep the sitting guidelines in mind and avoid awkward postures.

Question

What can you do if your desk is

too high??

Problems

Desk height is too high so I must raise my chair.

Solution = Foot rest and raise chair or install a keyboard tray.

If you cannot lower your workstation or install a keyboard tray then you must raise your chair.

Feet may dangle given chair height so a foot rest is needed.

Desks & the Overall

Workstation

Ensure proper layout and desk design

– Adequate space, height, etc

If unsure, contact me for help

What is the Correct Desk

Height?

It Depends!!

Regardless of what the desk height may

be the elbows should be in ~ 90 degree

angles when typing

90

Problems

If the desk is too high

– Shoulder elevation (upper back, neck and

shoulder discomfort)

If the desk is too low

– Elbow extension, rounding shoulders forward

(upper back, neck and shoulder discomfort)

Desk Too High

Desk is too high,

causes shoulder

elevation

Contact stress

(wrists)

Wrist flexion

Desk Too Low

Desk is too low

causing, slouching,

extension of arms

(elbows)

Wrist extension

Rounding shoulders

forward

Keyboard Distance

Keyboard is too far

away from the body

(reach, rounding

shoulders)

Keyboard is too

close to the body

Ergonomics Means

Adjustment There is no such thing

as one size fits all desk

(unless it adjusts)

– A ~30” desk (standard)

is too high for most

~14” difference in

seated elbow height

for 5th %tile female

and 95th %tile male

Solutions to Desk Height

Keyboard tray– One of the best solutions (adjustability)

– Some people dislike keyboard trays. Obtain what works for you.

– Request ergo eval for help

Other options

Desk is too high – Raise chair, use a foot rest

– Lower the desk (if feasible)

Desk is too low– Raise it up (bricks, wood, etc)

Main Goal:

Get the keyboard and mouse to the proper height to allow for the

~90 degree elbow angle!!

Mouse Positioning

Mouse

The mouse should be at the same height as

your keyboard and right next to it without

creating a reach.

Reach For The Mouse

NO Yes

Poorly Designed Desks

Desks which have lack of

space force mouse into

poor location

Increased reach or

awkward arm/shoulder

position

Reach for mouse

If the mouse is:

– Not close to the keyboard

– Causes a reach

If there is inadequate space for the mouse

on desktop, drawer or tray then………..

OPTIONS

Adjustable keyboard tray w/ mouse platform

Keyboard w/o 10-key function

Keyboard commands that replace mouse activity

Mouse Stage

Touch-Pad Keyboard

Alternate mousing hands

Trackball Mice

Mouse Alternatives

Mouse Position Goal

Get the mouse as close to the keyboard as

possible.

Use what works best FOR YOU!

Avoid reaching!!!!

Mouse Wrist Issues

Try to avoid excessive movements with the wrist

to control the mouse.

Other mouse options may work better

– Trackball, touchpad, roller mouse

Goal is to reduce wrist movements (repetition)

and awkward wrist angles (awkward posture)

Mouse Options

Ideal position for the

hand when mousing is

in the “hand shake”

position

Mouse shown helps

provides this position

Which mouse to use?

Which mouse you choose will vary on your preference and possible discomfort.

Trackballs– Reduce wrist, forearm movements

– Require greater thumb and finger movements

Touchpad– Greater thumb and finger movements

Vertical mouse– Greater forearm, shoulder movements

– Less emphasis on wrist and smaller muscle groups

I’ve Tried Everything!!

What is next?

Switch hands

Mouse with the non-dominant hand!!

Two mice

May be difficult but will reduce repetition

Pointer Speed

Change mouse pointer speed to “fast”

1. Control Panel

2. Printers and other hardware

3. Mouse

4. Pointer options

5. Select a faster pointer speed (change to fastest speed)

This will reduce movements (fingers, wrists)

Keyboard

Correct Typing Position/ Posture

Recommended Hand/Arm

Position

~90 degree angle in the elbows

– No arm extension

Elbows close to the torso

Forearms parallel to the ground

Shoulders relaxed (not rounded forward)

Wrist positioning

The wrists should be as straight

as possible when typing

Wrist extension - bad

Ulnar deviation - bad

Ideal - good

Ideal - good

Solutions

Wrist rests

Raise/lower keyboard

Ergonomic keyboards

– Tented/split

– Natural

Wrist Deviation Risk Factors

Any Deviation in the wrist can

lead to:

– Bursitis

– Tendonitis

– NOT CARPAL TUNNEL!!

Carpal Tunnel Syndrome (CTS)

There are no scientific findings which support that CTS is in any way related or caused by working on a computer (keyboard).

Personal factors play an increased role

– Smoking, obesity, age, gender, etc

Personal hobbies/work tasks

– Pinch grip w/wrist flexion

Keyboard Ideal Wrist Position

Wrists are not:

– Deviated (ulnar deviation)

– Extended

– Pronated

Hands should be in “hand shake” position

Keyboard shown provides this (expensive)

Keep the Wrists as

Straight as Possible

Reduce Typing and Mousing

Use Programs to eliminate repetition

Dragon Naturally Speaking Software

Break time Software

Etc

Goal in many programs is to reduce repetition

Unfortunately…… some programs can be

expensive, difficult to learn

• Poor ergonomics with respect to vision can lead to eyestrain, headaches, & neck pain.

Screen Clarity

If necessary, reposition the monitor to reduce

direct glare and reflections.

Choose screen colors that have sufficient

contrast but that do not clash with one another.

"20/20 rule" – Every twenty minutes, look twenty feet away for twenty

seconds.

Eyes need to focus at different distances from time to time.

This is Hard to

Read

This is Hard on

the Eyes

OTHER CONSIDERATIONS

Have regular eye

exams

Take regular vision

breaks

Use eye drops if

needed

Remove overhead

bulbs

Use task lighting

(lamps)

Reposition the monitor

Reduce Glare

Use blinds or curtains

to reduce the glare

from windows

Position monitor

perpendicular to the

windows

Monitor Positioning

Monitor Placement

Should be:

Directly in front of the body

– Not to the left or right

About an arms length away

– 18-30 inches

Technically >24 inches away

Top of monitor in line with the eyes

– See later pictures

Recommended viewing area (side view)

(top view)

Monitor placement

Problems

Monitor too low (neck

flexion)

– Awkward posture increases

fatigue, lack of blood flow

and oxygen, can impact

arms

Monitor too high (neck

extension)

– Awkward posture increases

fatigue, lack of blood flow

and oxygen, can impact

arms

TOO LOW!

Dual/Multiple Monitors

As close to each other as possible

Matching height

Phone

“NO”

Cradling the phone

Avoid cradling when possible

Use a headset

– When phone use is > 1-2 hours/day

Other solutions

– Speaker phone

– Shoulder cradle

Holding phone with the hand

Switching hands “YES”

Document holders

Problems

Without a document

holder one might

experience:

– Repetitive neck

rotation

Upper back, neck and

shoulder fatigue and

discomfort

– Eye strain

Varying of focus

Document holders

Should be as close to the monitor as possible.

At or close to eye level.

Right, left or below monitor.

Depending on what tasks you may be working on.

Document holders

This holder creates reach

Causes neck rotation

This holder reduces reach

is heavy duty

Causes neck flexion

Writing - Ideal Posture

Sit back

Avoid leaning forward

Tilt the writing surface

– Use a writing board/slant board

– Bring work up to you versus adjusting your body to the table height

Slant board provides better angle for writing and viewing (less neck flexion)

Writing/Typing in Combination

Ideal Recommended Setup

Keyboard at correct

height

Document holder

Screen at correct

height

Sitting back in chair

Wrist straight

Add Tools that Work for You!

Reaching

Avoid reaching for

any item

– Phone, calculator,

printer, tape, coffee

cup, etc

Pull items frequently

used closer to the body

Think about what you

are doing and arrange

the items you use

Pens/Pencils, Staple Removal

(Pinch Grip) Pinch grip of pens/pencils

can be a problem.

Alternative s can help

There is NO perfect setup

What do I do??– Get things setup

– Follow guidelines

Most importantly………….

– TAKE BREAKS

If you do not allow for breaks to avoid (frequency, duration, intensity) the chance for injury remains high. Following guidelines will help but breaks are crucial

Work Patterns

Work Breaks

Stretching

For more stretches and information go to:www.ehs.colostate.edu/ergonomics

Techniques to reduce the risks associated with

intensive computer and office work.

“Mini Breaks”

Alternate different

tasks throughout the

day

Get a drink of water

Do your stretches!

Get away from your

workstation

Take 1-2 minute

breaks every 30 to 45

minutes

– Should be a part of

your daily work

routine

Stretching!! Improves flexibility

Promotes better circulation

Prevents muscular injuries

Prevents muscular soreness and stiffness

Reduces tension and helps RELAX

Helps develop better awareness of your body and its muscles

Don’t rely solely on stretching

– Does not eliminate hazard exposure but can help

Setup your workstation correctly first

Stretching tips Stretch in a slow relaxed manner.

Stretch until you feel a slight pull in the muscles. Hold for 20-30 seconds. Don’t BOUNCE.

It takes 5-10 seconds for muscles to release its tension.

Never stretch to the point of pain. Use caution.

Breathe normally. Do not hold your breath.

ANY QUESTIONS?

Environmental Health Services

491-6745 main line

491-2724 my office

Frank.Gonzales@colostate.edu

www.ehs.colostate.edu/ergonomics