A normal neck has a gentle curve to it, the degree of which can vary according to the position you are in. But should you lose this curve, through injury, misalignment that is sustained over a long period of time, or for another reason, you may find the rest of your body's posture is affected, too.
Loss of cervical curve goes by a number of names, including flat neck syndrome, cervical kyphosis, military neck, and when the reduction in the degree of the curve goes into the opposite direction of normal, reversed neck curve. While not among the most severe of neck maladies, this condition may affect your well-being in one or more ways.
Why the Spine Curves
Your spine is divided into four curves. When viewed from the side, two curves—often called "normal kyphotic curves," or kyphosis—go backward. The other two curves sweep forward and are called "normal lordotic curves" or lordosis.
We are born with our kyphotic curves; we develop our lordotic curves as we gain the ability to lift our head and learn to walk. For this reason, kyphotic and lordotic curves are sometimes referred to as primary and secondary curves, respectively.
Spinal curves help balance the spinal column and work together to counteract gravitational compression by redistributing the stress forward and backward rather than just up and down.
Flat Neck Syndrome Symptoms
Flat neck syndrome, also known as a military neck, is a condition in which the normal lordosis of the cervical spine diminishes, or is even fully lost. But the loss of curve can go well beyond that. After the neck curve reaches straight, it may even move into the opposite direction, a condition aptly named reversed neck curve.
A decreasing lordotic curve is not the only characteristic of flat neck syndrome. There can also be increased flexion (forward bending) at the joint between the skull and the first bone of the neck.1 The excessive bending at this location exaggerates extension through the cervical spine and all of the spinal structures below.
While this extension, known as an axial extension, can be beneficial in correctly spinal curvature problems, it can be counterproductive if your spine remains in that position. It essentially takes your spine out of its neutral position and increases the gravitational compression placed on the spine.
With an axial extension, there's less movement available, partly because you have to engage the muscles so strongly to maintain the position.
The loss of a cervical curve makes the muscles at the front of your neck far less flexible and may overstretch other muscles, including the anterior and posterior paraspinal muscles and suboccipital muscles.
Flat neck syndrome can affect the curvature in other parts of the spine, contributing to a problem known as a military back. The condition, in which the upper back is abnormally flat, increases the risk of spinal compression and degeneration.
Some of the causes of flat neck syndrome and/or reversed neck curve include:2
Degenerative disc disease
Spine surgery (called "iatrogenic injury")
Neck injury or trauma
Tumors, infection or systemic disease
Risks of Injury
Flat neck syndrome can often place excessive stress on the ligament nuchae, the ligament which limits how much neck flexion you can do. It is located at the back of your neck, starting at the back of the skull, and extends to the last bone in the cervical spine.
If you have flat neck syndrome, you may be predisposed to injury because the restriction of movement reduces the shock-absorbing capacity of the spine. Moreover, because the condition is not inherently associated with pain, you may not be aware of your limitations until an injury actually occurs.
Some injuries in people with flat neck syndrome can extend to the spinal cord itself, causing pain and pressure in the neck, numbness or tingling at the base of the skull, double vision, and difficulty swallowing.3
When to See a Doctor
If you have characteristics of flat neck syndrome and are experiencing pain or abnormal sensations of any sort, particularly in the neck or at the base of the skull, see your doctor or ask for a referral to an orthopedic specialist.
While most people do not need treatment for a flat neck, some may benefit from massage, exercise and/or physical therapy. One particular exercise that nearly every health provider who treats this condition gives to their patients is the cervical retraction exercise. In rare cases, surgery may be needed if a spinal cord disruption occurs.