The vertebral column has four curvatures, the cervical, thoracic, lumbar, and sacrococcygeal curves. The thoracic and sacrococcygeal curves are primary curves retained from the original fetal curvature. The cervical and lumbar curves develop after birth and thus are secondary curves.
What is primary curvature?
The thoracic and sacral (pelvic) curves are termed primary curvatures, because they alone are present during fetal life. This definition incorporates text from a public domain edition of Gray’s Anatomy (20th U.S. edition of Gray’s Anatomy of the Human Body, published in 1918 – from http://www.bartleby.com/107/).
What are the secondary curves of spine?
Gradually secondary curves develop in the cervical and lumbar regions; Lordotic curves. These curves will continue to develop until growing stops. Spinal curves are either kyphotic or lordotic.
|Type of Spinal Curves||Curve Description|
|Sacral Kyphosis||Sacrum fused in a kyphotic curve|
Why Kyphotic curves are considered primary curves?
Why are kyphotic curves “primary curves”? Because they are present in the fetal position/the C shape. Why are lordotic curves “secondary curves”? Because they occur after birth; cervical lordosis begins when an infant begins to lift its head and lumbar lordosis begins when the baby stands erect and begins walking.
What is a normal spine look like?
The normal spine has an S-shaped curve when viewed from the side. This shape allows for an even distribution of weight and flexibility of movement. The spine curves in the following ways: The cervical spine curves slightly inward, sometimes described as a backward C-shape or lordotic curve.
How much curve in spine is normal?
While a normal spine curve at the thoracic region should be within 20 to 50 degrees, kyphosis forces a curve greater than 50 degrees. Patients experience moderate back pain and fatigue. With kyphosis, the curvature forces the body to hunch over and appear as if you are lounging.
Is it normal to have a curved spine?
In normal, healthy individuals, the spine always curves. However, it occurs in a very specific way. SpineUniverse explains that this curve is normally only visible when viewed from a side (aka lateral) view.
Is an abnormal curvature of the spine?
Scoliosis is an abnormal curvature of the spine. The normal shape of a person’s spine includes a curve at the top of the shoulder and a curve at the lower back.
What are the three main parts of a typical vertebra?
A typical vertebra will consist of a body, a vertebral arch, and seven processes (Figure 7.23). The body is the anterior portion of each vertebra and is the part that supports the body weight.
What age do secondary curvatures of the spine develop?
The cervical and lumbar curves are compensatory or secondary curvatures, and are developed after birth, the former when the child is able to hold up its head (at three or four months), and to sit upright (at nine months), the latter at twelve or eighteen months, when the child begins to walk.
Why are the curves of the spine referred to as primary and secondary?
Primary and Secondary Curves
The thoracic and sacral curvatures are termed primary curves because they are present in the fetus and remain the same in the adult. As the child grows, lifts the head, and begins to assume an upright position, the secondary curves (cervical and lumbar) develop.
What is the purpose of the secondary curves?
The secondary curves in the cervical and lumbar regions are called compensatory curves because they develop as a compensatory mechanism for developmental changes in posture. These compensatory curves facilitate holding the head up and walking upright.