Guest Author - Marji Hajic
In ergonomics, you will frequently hear the term “neutral positioning”. Let’s clarify what this term means. This is part 2 of a 2 part series discussing the elbow, shoulder and head.. Part 1 covered the fingers, wrist and forearm.
According to the medical dictionary at thefreedictionary.com, the neutral position of the arm is a body position to be assumed that prevents cumulative trauma to the arm. It incorporates proper placement of the wrist, elbow, and shoulder.
The Importance of Neutral Positioning
Awkward positioning at your computer can increase pressure or stretch on the nerves or cause friction and strain as the tendons move through or around pulley systems. This can lead to chronic inflammation and pain. Being positioned in the more relaxed and neutral position can help ease strain on the body and improve your work comfort.
An elbow that is bent more than 90 degrees places a tremendous amount of stretch on the ulnar nerve (the “funny bone” nerve that runs through the groove on the inside of the elbow). Your keyboard height should allow the elbow to be open to a minimum of 90 degrees, preferably just a bit more. This will also help your shoulders relax (more on that later). This is particularly true for women who have a larger “carrying angle” (the angle of the upper arm in relationship to the forearm when your hand is placed at your side, palm forward; very rarely is this a straight line but veers a bit towards the thumb side of the hand) or who are well-endowed in the chest (the elbows are positioned further from the body when they are relaxed at the side causing the wrist to compensate by angling more on the keyboard).
For more information, see Cubital Tunnel – Carpal Tunnel’s Counterpart.
Most people carry tension in their shoulders and they do not even realize it. At your work station, try to keep your shoulders relaxed. Common causes of elevated shoulders include arm rests that are too high and work stress.
Try this – raise your shoulders up towards your ears and hold forcefully for five seconds. Now take a deep breath, release the breath and let all the muscle tension go and let your shoulders relax back down. Feel the difference between the tension and the relaxed state? Another activity to help you relax your shoulders – sit in your work chair with your shoulders relaxed, elbows tucked into your sides. Have a friend modify the height of your arm rests to just below your elbow height. Then have the friend move behind you and look at your shoulders. Do they seem elevated or are they relaxed? Is one shoulder higher than the other?
Try this exercise – Every hour or so, perform shoulder circles emphasizing the movement of the shoulders moving back and down.
For more information, see Perfect Posture - The Basics.
It is not uncommon for the head to begin falling forward with frequent desk and computer work. Neutral alignment occurs with the head and shoulders stacked on top of each other. The farther the head falls forward, the more tension is placed on the nerves of the arms. Also, the back muscles become weak and the chest muscles become tight creating postural imbalance.
Try this – Have a friend stand at your side and look at your head, shoulders and elbows. Are your ears, shoulders and elbows lined-up in a vertical line? Or are the shoulders rounded forward and the head dropping forward?
Try this exercise – Start in good posture with your head and shoulders in alignment. Now tuck your chin back towards your chest (as if you are trying to give yourself a double-chin). Keep your eyes on the horizon while performing this exercise holding your head straight and not tilting it up or down. Hold for five seconds.
For more information, see The Neck & Repetitive Strain Injuries.
Part 1 - Neutral Positioning of the Fingers, Wrist & Forearm
Marji Hajic is an Occupational Therapist and a Certified Hand Therapist practicing in Santa Barbara, California. For more information on hand and upper extremity injuries, prevention and recovery, visit Hand Health Resources.