Choosing Your Ergonomic Office Chair- You Need the Right Height

Elizabeth Schnurr
Problems:
  1. Why do I have pain in my forearm muscles?
  2. Why do I have lower back pain?

Does this scenario sound familiar? Your employer ordered new office chairs, which are all the same. You are short in stature. Your keyboard is on the desk top. Your chair seat goes up to about 18 inches, and your desk is about 29 to 30 inches high. You cannot get your bent elbows to be at the same height as your keyboard on the desk, so you pull your chair and arm rests underneath the desktop, and push your keyboard back, and rest your forearms on the desk top.

What is the problem? Ergonomically, we should not be resting our arms on the hard desktop. It causes contact stress to our arms and elbows. The arm rests of the chair, which should ideally be cushioned, are meant to support our arms, with our elbows at a 90-degree angle. Another problem is that you will be sitting in a forward shoulder and upper back posture, leaning forward with your lower back. Lower back flexion can eventually lead to lower back pain. Despite the chair having a backrest, you are not using it if you are leaning forward. Your shoulders are also in a flexed position, with your arms reaching forward farther and higher.

Another problem that I have encountered lately with resting the hands in front of the keyboard is an increase in forearm pain from repetitive strain. Try something for me: Put one hand forward on your desk, resting the base of your hand on the desk, and lift your hand and fingers, alternating as if you are keyboarding. Put your other hand on top of your forearm. Where do you feel muscles activating? In the top of your forearm? Those are your finger extensor muscles. Now put your hand over the keyboard, and strike the keys with your fingers only moving downward, keeping your wrists straight and not extended or dropped. Feel your forearm again. Are the muscles contracting less? They should be.

Keyboarding technique is the same as playing the piano. Your hands should be above the keys, with your fingers cupped and bent. The forces should be downward and light, and your fingers should not have to lift higher than required to move them to another key. Keeping your wrists flat or straight will help prevent stretching of the tendons in your inner wrist, which could cause Carpal tunnel inflammation.

Therefore, is your chair related to the pain you are feeling in your forearms? YES, it could be.

If your chair goes to the right height, where your bent elbows can be positioned at the same height as your keyboard, and supported by the arm rests, you should be able to sit with your back supported against the back rest. What was the underlying problem for the pain you may have experienced in the top of your forearms? Should you buy a new “ergonomic” keyboard? No! The real problem is that your chair seat is too low and doesn’t go high enough. Also, you are resting your hands in front of the keyboard, causing increased muscle activity in your forearms.

Ergonomic Solutions:

  1. Get a chair that goes high enough for its armrest and your bent-elbows to be at the same height as your keyboard.
    OR:
    Install a height adjustable keyboard tray, to lower your keyboard to your bent-elbow height. (This option only works if you have the right workstation set up and the keyboard tray will not be in your way.)
  2. Sit with your back against the back rest of the chair.
  3. Support your arms on the arm rests while typing or between periods of typing, allowing your hands to float over the top of the keys without over-activating your forearm extensor muscles.

Pictures:

Forearm with muscle pain in extensor muscles

Sitting with hands keyboarding and resting in front of keyboard.