Guidelines for Computer Ergonomics

In the first instance we should all remember to set ourselves up properly each time we sit at our desks, particularly with the current trend towards ‘hot desking’ and sharing of workspaces and chairs. Understand your chair and how it works: Check the seat height and the back rest height and angle. Does it have a free-flow adjustment, arm rest or seat pan slide adjustment, or even a tension control?

A few general tips for the ideal start positioning for both chair and desk:

CHAIR:
Start by sitting away from the desk on your chair. Sit comfortably with your bottom all the way to the back of the chair and lean against the backrest. People often make the mistake of perching on the edge of the chair. Even with good core strength, in time you will slouch and slump forward, so always try and use the backrest. There should be 2-3 fingers width of space between the edge of the seat pan and the back of the knee. This is where you can use the seat pan slide to accommodate and it simply depends on how long your thighs are. Angle the back so it is just over 90 degrees, allowing a slightly relaxed posture and not one that is going to push you forward too much. If there is a free- flow function, make sure you adjust the tension control to match your body size and weight. The angle of the seat pan can often be adjusted to drop down at the front. This may be useful if you have hip issues or are pregnant. Finally, check that the castors are appropriate for the surface on which they are used. You can get rubber coated castors for use on hard flooring which will prevent too much slipping around.

DESK:
Now position the chair at the desk.
Adjust the chair height so the elbows are at the desk height when at 90 degrees. If your feet then leave the ground you will require a foot rest (in general those below 5 ft 6 will likely need one.)  Always sit with both feet on the floor or foot rest and do not sit in a cross-legged position. Fixed arm rests can often be removed and should be if they prevent you from sliding in underneath the desk. You should try and tuck right in and under, leaving little space between your body and the desk. Sitting height can often influence wrist position on typing and in turn problems such as RSI and Tennis Elbow. If your elbows are pointing out while typing you are probably sitting too low down.

KEYBOARD:
Being a proficient touch typist will lead to much less nodding of the head and neck when alternating the gaze between keyboard and screen. If you are no so adept at typing, a slight recline on your seat will help to reduce the nodding motion. Try not to only use one finger when typing or to hit the keys too hard. Long nails may also influence the position of your wrist. Ideally you should be able to type without resting your arms on the desk. If you have problems with your wrists there are supports available, but make sure they are not fixed too rigidly.

MOUSE:
As the mouse is used often, keep it close and don’t over-reach. You can even try and alternate from right to left to avoid overuse injuries. Relax your hand and grip, especially when not in use. Do not hover the finger over the click button. For those who already have tendon issue there are several different types of mouse available – for example, a vertical mouse is useful for those with Tennis Elbow. Someone mainly doing graphic work may prefer a stylus type mouse or an accounts based job may prefer a separate number pad.

SCREEN:
Next look to the screen as this will dictate your head position. Ideally it should be an arm’s length away (approx. 50-70cm).   It should be directly in front of you level with your line of sight. If it is too low, do not move the chair down, instead move the screen up. You may prefer the screen to be a little lower to reduce the nod range if you often have to look at the keyboard when typing. It is a good idea to have screens perpendicular to any windows to avoid glare. Check you are not leaning forwards to read the screen. If eyesight is a problem check your prescription is up to date, or even change the font size or zoom percentage.

PAPERWORK:
A document holder is relatively inexpensive and can make a great difference. It should be used in-between the keyboard and the screen and you should try to keep everything in line so you are not repetitively looking to one side and back.  

TELEPHONE:
The obvious thing to avoid here is tucking the phone between your ear and shoulder to continue typing. Hands free headsets are of course the perfect solution to this problem.

ENVIRONMENT AND BREAKS:
Keep the things you use most often closest to you. Look to where the phone is, the printer and other office gadgets. Think about the temperature of the office and windows and try not to sit in a draft. It is advised to get up every hour or so for a change in posture and to give your eyes a rest. Conversely if you are up and down all the time, make sure you are strict on sitting back down correctly and avoiding the ‘perch’. Give yourself an excuse to get up … move to the printer, drinks machine, etc … try not to stay at your desk to eat your lunch. Check how much you are using mobile devices away from your workstation:  I recently had a patient suffering from RSI after playing too much “Candy Crush”!!

LAPTOPS, TABLETS AND PHONES:
Laptops are supposed to be for occasional use. Of course they are often used far more than this, and in less than ideal positions – especially at home where it is obviously not advisable to be sitting on your sofa using the coffee table as a ‘desk’! This is a particular problem amongst children with their study/homework postures. Whilst they may feel no problems at the time and may resist advice, it is of course an accumulative affect.

There are laptop stands and separate keyboards that offer a solution to more than occasional use. There are even tablet stands available. The general advice is to bring or hold these devices up. If the head weighs between 10-12lbs at 0 degrees of flexion the pressure on the neck increases 6 times when the head is at 60 degrees of flexion – a lot of muscular overuse over time!

 

These are just guidelines and although not every workstation can be easily changed to achieve the ideal, there is usually at least something that can be improved or enhanced. There are many aids available to help with these changes and if you require more information or have an individual enquiry for an assessment then please contact one of our professionals here at Springbank Clinic.