Forgive me for getting a little nerdy this morning, but I think this is wicked cool.  Let’s talk physics.  Here is a great explanation why a forward head posture (your head being in front of your shoulders) can lead to headaches and severe muscle tension in the neck and shoulders.

Simply said, you are more likely to have head and neck problems if your head is flexed (like during most computer work) or is postured too far in front of your shoulders.

The neck is designed with a nice  curve to help balance the weight of the head.  When the head moves forward, more weight (load in physics terms) is placed in front, which in turn requires more work to be done by the muscles in the back of the head and neck.

Have you ever played on a seesaw and just for fun, kept the other person balanced in the air while you sat on the ground laughing?  You were in complete control of their destiny.  The only way the person could get down was to 1. beg for mercy, 2. gain weight instantaneously, or 3. put all their weight on the very end in order to change the leverage- illustrated by the following formula,compliments of engineeringtoolbox.com

F_e = F_l d_l / d_e (1)

where

F_e = effort force (N, lb)

F_l = load force (N, lb) (note that weight is a force)

d_l = distance from load force to fulcrum (m, ft)

d_e = distance from effort force to fulcrum (m, ft)

This is called a first class lever in physics.  The neck is balanced on a fulcrum of a curved spine and muscles pull back on the head to lift the face up.  The more your head moves forward then the more these muscles must work to keep the head balanced.  Kapit and Elson explain it best: “By flexing the neck and posturing the head forward and downward, the load (head weight) is appreciably increased and the muscular effort to hold that posture may induce muscle pain and stiffness/tightness (overuse).”1 Boone and Birnbaum discovered that “the flexed position puts significantly more strain on the erector spinae (a 4-fold increase in force).”2 It is like playing seesaw with an elephant- the weight is too heavy to hold up.  This is exactly what happened during these past 34 minutes while using my computer to write this post!

So what does this mean?  Simply said, you are more likely to have head and neck problems if your head is flexed (like during most computer work) or is postured too far in front of your shoulders. This is why it is important to get adjusted and maintain your cervical curve.

Dr- Jerry

The anatomy coloring book. Kapit W. and Elson L. 1993 p.35
The science of Levers. Tommy Boone, PhD, MPH, FASEP, EPC and Larry Birnbaum, PhD, MA, EPC p51.