Dorsal Kyphosis Definition - Medical and Measurements

Depiction of excessive kyphosis and forward head posture.
Depiction of excessive kyphosis and forward head posture. CLIPAREA

Kyphosis Definition

The term kyphosis refers to one type of spinal curve whose direction goes towards the back when you view the body from the side.

A kyphotic curve, as it's often called, occurs naturally in your thoracic spine as well as your sacrum, but it is not natural in the cervical (neck) and lumbar (low back) regions. The neck and low back curves go into a forward direction when you view the body from the side.

 These called lordotic curves, or lordosis. If you need clarification, read more about spinal curves.

This is not to say that kyphosis is always normal in the upper and/or mid-back area. Kyphosis can be excessive, and that's where the problems begin.

Also, the sacrum is one bone that is fused together from five. This means the degree of its curve is not affected by things like posture habits or the condition of your muscles. And so the discussion of excessive kyphosis to a great extent only applies to your thoracic spine — i.e. your mid to upper back area.

Kyphosis Curve Measurement - What is Normal and What is Excessive?

Historically, the thoracic kyphotic curve has been measured using a calculation called the Cobb Angle. (The Cobb angle is also used to determine the degree of scoliosis curves.) More recently, however, researchers have been developing other methods of measurements.  

At any rate, if your thoracic kyphosis measures between 20 and 40 degrees, it's considered normal.

Above 45 degrees, your doctor may diagnose you with excessive kyphosis, or hyperkyphosis, which are two terms that basically mean the same thing. Other names include: Gibbous deformity and Dowager's Hump.

Hyperkyphosis

Hyperkyphosis affects many different types of people (often for different reasons) with senior citizens, adolescents whose skeletons haven't matured yet, office workers, people with scoliosis topping the list.

A number of conditions can lead to excessive kyphosis, including: Muscle weakness, degenerative disc disease, vertebral fractures, genetic conditions, or simply advancing age. Excessive kyphosis may affect your mobility or increase your risk for falls or fractures, according to Katzman, et. al, in their study entitled "Age-Related Hyperkyphosis: Its Causes, Consequences, and Management." The study was published in the June 2010 issue of the Journal of Orthopaedics and Sports Therapy.

No matter what the cause is, getting hyperkyphosis diagnosed and treated early may help you avoid the negative impact it can have on your quality of life. Hyperkyphosis may cause headaches, shoulder problems, reduced lung functioning, neck pain and/or upper or mid-back pain.  

Types of Hyperkyphosis

To learn more about the different types of excessive kyphosis check out the articles in this partial list:

    Sources:

    Lewis, J.S., Valentine, R.E., Clinical measurement of the thoracic kyphosis. A study of the intra-rater reliability in subjects with and without shoulder pain. BMC Musculoskeletal Disorders. 2010.

    Scheuermann's Kyphosis. Duke Orthopaedics Presents Wheeless' Textbook of Orthopaedics.

    Katzman, Wendy Bl, Wanek, Linda, PT, PhD, Shepard, PhD, Sellmeyer, D. E. Age-Related Hyperkyphosis: Its Causes, Consequences, and Management. J Orthop Sports Phys Ther. 2010 Jun; 40(6): 352–360.

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