Loss of Cervical Curve and Cervical Kyphosis

Is Your Neck Curved Reversed?

X-ray view of head, neck and thoracic areas.
Cervical kyphosis is a posture problem that sometimes causes neck pain. Science Picture Co./Collection Mix: Subjects/Getty Images

Military Neck and Cervical Kyphosis -  Definition and Background

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 compensatory curves, respectively.

All curves, including the lordosis in the neck, help balance the spine and protect it from the compressive effects of gravity. In fact, the curves work together to do this. Carolyn Kinser and Lynn Colby, both physical therapists, and authors of Therapeutic Exercise: Foundations and Techniques, 4th edition comment that the flexibility contributed by the curves offers 10 times more resistance to this type of compression than a straight spine.

Military neck is a condition in which the normal lordosis of the cervical spine diminishes, or is fully lost. Cervical kyphosis is the condition in which the neck curve goes past straight, and reverses direction to become kyphotic. YI, military neck is known by a number of other names including, straight neck, flat neck, loss of cervical curve.

Cervical kyphosis is also called reversed neck curve. 

Military Neck and Cervical Kyphosis - Characteristics

A decreased or reversed lordosis in the neck is not the only characteristic of military neck/cervical kyphosis. Kinser and Colby also report an increased flexion (i.e. forward bending) at the joint between the skull and the first bone of the neck (called the atlas.)  

They add that the excessive bending at this location exaggerates axial extension, which is a stretching or lengthening that can go through the trunk and its structures, especially the spine.  

Amy Matthews, internationally regarded yoga teacher, Body-Mind Centering® practitioner, and author of Yoga Anatomy says when a yoga or Pilates teacher gives the instruction to "lengthen your spine," the result is usually axial extension.  

But Matthews asserts that axial extension is not always ideal for the body, saying "it's not the most efficient use of the musculoskeletal system." 

"Taking curves out of your posture means your posture no is longer neutral," she explains. 

"In axial extension, there's less movement available, partly because we have to engage the muscles so strongly to maintain it." 

A loss of some or all of your cervical curve makes the muscles at the front of your neck less flexible, according to Kinser and Colby. They say the condition may also excessively stretch your levator scapula, scalene, and sternocleidomastoid muscles.

They also say that a flat neck sometimes accompanies another posture problem known as military back or flat upper back.  

Causes of Straight Neck and Reversed Cervical Curve

Some of the causes of a straight neck and/or reversed neck curve include:

Do Cervical Kyphosis or Loss of Cervical Curve Cause Pain?

While the jury is still out as to whether flat neck and reversed cervical curve cause any symptoms, according to Kinser and Colby, they can cause pain for 3 reasons: Your TMJ joint can become dysfunctional based on a habit of having your mandible or jaw forward as part of the posture, you'll likely have  predisposition to injury because you lose the shock absorbing function that a normal neck curve provides, and stress to a ligament called the ligament nuchae.

And at least one research study has measured the point at which military neck becomes painful. In 2005,  McAviney and associates used the posterior tangent method to measure 277 neck x-rays. They then sorted the x-rays into 2 groups:  Cervical complaint, and non-cervical complaint. The researchers found that patients whose x-rays were 20 degrees or less were more likely to have neck symptoms. (The authors report that the clinically normal range is between 31 and 40 degrees.)  The study was published in the Journal of Manipulative Physiological Therapeutics in March 2005.

Military Neck and Cervical Kyphosis - Treatment

While most of the time, you don't need treatment for a military neck, many people, myself included, benefit from chiropractic. Massage, exercise and/or physical therapy may also be helpful.  In rare cases - when the spinal cord is disrupted - surgery may be appropriate. Check with your doctor if you have concerns or questions about your military neck and/or cervical kyphosis.

 

Sources:

Kinser, C., Colby, L.A., Therapeutic Exercise: Foundations and Techniques. 4th Edition. F.A. Davis Company. Philadelphia, PA. 2002.

Kyphosis. MedicineNet.com. Last Reviewed June 2015. Accessed July 2015. http://www.medicinenet.com/kyphosis/article.htm

Matthews, A. Axial Extension. EmbodiedAnatomy.net website. Accessed July 2015. http://embodiedanatomy.net/axial-extension/

McAveny, J. et. al. "Determining the Relationship Between Cervical Lordosis and Neck Complaints" Journal of Manipulative Physiological Therapeutics. March 2005. Accessed July 2015. http://www.jmptonline.org/article/S0161-4754(05)00059-X/abstract

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