COMPUTER ERGONOMICS: A GUIDE FOR TEACHERS

Computer Ergonomics is the study of designing job tasks, workstations, equipment and tools to fit people’s physical capabilities in an environment where they use computers. This field of study promotes safe and healthy workplaces for computer users and attempts to prevent human and monetary costs from computer-related health problems. Because of the increase in computer usage in schools, this guide has been created for Computer Science teachers and those teachers whose students work extensively on computers. This guide will discuss the effects of Repetitive Strain Injury (RSI) and ways in which to prevent this injury from occurring. In addition, it will give some suggestions on how to set up ergonomically-safe computer workstations in schools, and provide tips on sitting posture and stretch exercises for students. This guide will hopefully help teachers recognize potentially serious problems and reduce the risk of student injury.

Repetitive strain injury (RSI) occurs from the repeated movements of the hands and arms while doing tasks on computer keyboards and mice and also from a lack of adequate rest and breaks. Damage is done to the tendons, muscles, nerves as well as the shoulder and neck areas. RSI is often a very painful condition that is difficult to cure. A person of any age who works at length on computers is susceptible to this type of injury, even young physically fit people. Many people with RSI have had to leave their careers as a result of becoming permanently disabled or unable to perform their job tasks. In addition, it may difficult for them to carry out daily routine tasks such as driving or dressing themselves. There are many different types of repetitive strain injuries; Carpal Tunnel Syndrome, Tendinitis, Bursitis, Tenosynovitis, DeQuervain’s Syndrome are just a few examples of injuries that could cause individuals great pain.

Here is a list of symptoms that can occur for someone who has RSI (taken from http://www.engr.unl.edu/ee/eeshop/rsi.html):

• Tightness, discomfort, stiffness, soreness or burning in the hands, wrists, fingers, forearms, or elbows

• Tingling, coldness, or numbness in the hands

• Clumsiness or loss of strength and coordination in the hands

• Pain that wakes you up at night

• Feeling a need to massage your hands, wrists, and arms

Repetitive strain injury can be easily prevented by having correct typing technique and posture, the right equipment setup, and good work habits.

The picture below shows the incorrect way to type on a keyboard (taken from http://www.engr.unl.edu/eeshop/rsi.html ):

Wrists should not be bent to the side. Rather, the fingers should be in a straight line with the forearm, similar to the picture below:

It is also important to make sure that the wrists are not resting on anything while the user is typing. Use a light touch when typing; do not pound the keys.

Below is a diagram showing the proper posture of an ergonomically aware user (taken from the University of California’s Campus Occupational Health Program 1992):

Here are several tips to consider when setting up computer workstations in the classroom:

• Ensure each computer terminal has a detachable keyboard, brightness and control knobs, tiltable screen, no perceptible screen flicker and reduced electromagnetic fields (EMF) emissions.

• Ensure each chair has a seat and a back that are easily adjustable for height and tilt from seated position. The back of the chair should provide firm support for a user’s lower- and mid-back. Chairs should be upholstered and padded and have moveable arm rests (to prevent shoulder fatigue)

• Ensure each computer table is bi-level, easily adjustable from a seated position and has adequate tabletop space and legroom.

• Other accessories that may be helpful include a document holder (adjustable to screen height), a wrist rest (padded and movable), a foot rest (for users whose feet do not rest flat on the floor) and a glare screen with grounding wire.

• To avoid eyestrain, reduce glare on the screen by ensuring that light does not shine directly into the user’s eyes or onto the screen.

Here are several tips and stretch exercises to try that will lead to effective and safe work habits:

• Take frequent short breaks during class time to allow students to stretch their bodies and rest their eyes.

• Alternate tasks if possible to prevent constant keyboard work.

• Teach students these stretch exercises (taken from http://www.uhs.berkeley.edu/FacStaff/Ergonomics/ ):

• Sit or stand up straight with your shoulders relaxed. Look straight ahead.
• Slowly turn your chin toward one shoulder.
• Hold for 10-20 seconds.
• Repeat on other side.
• Do each side twice.

• Sit or stand up straight with your shoulders relaxed. Bend your elbows so that your forearms are approximately parallel to the floor.
• Gently stretch your fingers out like a fan. Keep your wrists straight.
• Hold the stretch for 10 seconds.
• Relax, then bend you fingers at the knuckles. Keep your wrists straight.
• Hold for 10 seconds.
• Stretch your fingers out again for 10 seconds.

• Sit or stand up straight.
• Hold one arm out straight in front of you with your elbow straight. Push your palm away from you with your fingers up.
• Gently bend wrist back by pushing on fingers of outstretched hand with opposite hand.
• Hold for 5 seconds.
• Repeat on opposite hand.

• Sit or stand up straight with your shoulders relaxed. Look straight ahead.
• Put your hand on your back with your elbow pointing up toward the ceiling.
• Gently pull your elbow behind your head with your opposite hand until you feel an easy stretch in your shoulder or upper arm.
• Hold for 30 seconds.
• Repeat on the opposite side.

• Sit or stand up straight with your shoulders relaxed. Look straight ahead.
• Lift your shoulders toward your ears until you feel a slight tension in your neck and shoulders.
• Hold for 5 seconds.
• Relax your shoulders into their normal position.
• Repeat 2 or 3 times.

• Sit or stand up straight with your shoulders relaxed. Look straight ahead.
• Interlace fingers behind your head with your elbows out to the side.
• Pull your shoulder blades together in back until you feel a slight tension in your upper back and shoulder blades. Don't arch your back.
• Hold for 8 to 10 seconds, then relax.
• Repeat several times.

• Stand with your feet about shoulder width apart. Don't lock your knees.
• Place your hands just above your hips with your fingers pointing downwards.
• Gently push your palms forward, bending your back at the waist.
• Look straight ahead. Don't throw your head back.
• Hold a comfortable stretch for 10 to 12 seconds.
• Repeat twice.

http://www.uhs.berkeley.edu/FacStaff/Ergonomics/

http://www.engr.unl.edu/eeshop/rsi.html

http://www.eecs.harvard.edu/rsi/

http://www-ehs.ucsd.edu/vdt.htm

http://www-ehs.ucdavis.edu/sftynet/ergo/sn-96.html

http://ehs.ucdavis.edu/ergback/office/office1.html

http://www.me.berkeley.edu/ergo/tips/tips.html