such as stiff neck and neck pain, sudden apnea or hyperventilation, sudden sugar or blood pressure drop (e.g. sentiment of sudden exhaustion or falling forward)
Control posture, eat a candy or something salty, replenish electrolytes?
Reference used for following text: Eric Dalton blog
When looking at a computer screen are your eyes forward of your sternum for more than 3 cm?
[zygomatic arch (under the eye) more than three centimeters forward of the sternoclavicular joint?]
Instead of having to support a 5.5Kg head because of gravity, if you bend forward, then for each 2.5cm (1 inch) you will have to support additional 4.5Kg.
If this happens you contract your neck muscles in order stay at that position - which is far away from the natural position. This is called an isometric contraction (same metric, you don’t run any distance, you don’t move your head forward, you just keep it immobile forward).
In this way you are actually sending your muscles to a continuous contraction in order to maintain an unnatural position (a position quite distant to the body’s "perfect" engineering).
Muscle hypercontraction occurs and the term muscle spasm or myospasm (related to spasmism) is often used to describe this condition linked to muscle rigidity and fatigue.
Blood circulation becomes stagnant, blood vessels are being squeezed, and blood circulation diminishes. So does oxygen.
Muscle cells burn a lot of energy and produce a lot of waste byproducts, like lactate or lactic acid. The latter acidic compound which would be degraded if there was sufficient oxygen supply now builds up.
Noxious byproducts trigger nociceptors, an inflammatory reaction is initiated. Pain-inducing compounds generate the feeling of pain.
These substances also inform the brain that serious damage to other structures e.g. ligaments could ensue and therefore an additional protective muscle spasm (hypercontracture) is activated. It is of interest that a doctor could feel muscle spasm on the opposite side of an overstretched area).
This will only stop if the initial stimulus, the head bending forward is corrected.
Reference used for above text Eric Dalton blog
Associated page including muscle image – Excerpt:
“The gluing process:
“The seven deepest myofascial layers traversing the C7-T1 junction are particularly vulnerable to sustained isometric contraction from forward-head postures (Figure 1). With time, the slick lubricating fluid designed to provide smooth gliding of individual fascial sheaths dehydrates, thickens and becomes adhesive. The result: fascial adhesions, myospasm and muscle contractures.”
As mentioned at Dr.Russell Schierling’s blog: Head in forward posture can add up to thirty pounds (13.6 Kg) of abnormal leverage on the cervical spine. This can pull the entire spine out of alignment. Forward head posture (FHP) may result in the loss of 30% of vital lung capacity. Would you be surprised that your neck and shoulders hurt if you had a 20-pound (9.1 Kg) watermelon hanging around your neck? Rene Cailliet M.D.
Interesting article: Mechanisms of Myofascial Pain
Note: Fascia is the “muscle wrap”
Interesting book - excerpt: “Let’s take the example of someone who works for extended hours in front of a computer."
Image source link
https://en.wikipedia.org/wiki/Trapezius_muscle
You can locate it using the following wikipedia picture and the link
https://en.wikipedia.org/wiki/Sternocleidomastoid_muscle
https://en.wikipedia.org/wiki/Levator_scapulae_muscle