Names of the Curves The term lordosis is used in the same way. Called the primary curve, only the kyphotic curves (thoracic and sacral) are present when you are born, together forming one big C shape. The others develop as you acquire the ability to lift your head (cervical curve) and learn to walk (lumbar curve.)

Spinal alignment and curvature can be altered in many ways. They can occur as a result of a birth defect, a child’s growth, aging, injury, or previous spine surgery. The most common type of spinal deformity in adults is degenerative scoliosis. Figure 2.

The four movements measured are flexion, extension, lateral flexion and rotation. Flexion is forward bending; extension is bending backward; lateral flexion is side bending; and rotation is a twisting motion.

The vertebral column is curved, with two primary curvatures (thoracic and sacrococcygeal curves) and two secondary curvatures (cervical and lumbar curves).

Primary and Secondary Curves As the child grows, lifts the head, and begins to assume an upright position, the secondary curves (cervical and lumbar) develop. The cervical curve forms when the infant is able to hold up his or her head (at three or four months) and sit upright (at nine months).

Illustration shows the regions of the spine. When viewed from the side, the normal spine has three gentle curves. These curves are important for balance and they help us to stand upright. If any one of the curves becomes too large or small, it becomes difficult to stand up straight and our posture appears abnormal.

There are three main types of spine curvature disorders, including:

• Lordosis. Also called swayback, the spine of a person with lordosis curves significantly inward at the lower back.
• Kyphosis. Kyphosis is characterized by an abnormally rounded upper back (more than 50 degrees of curvature).
• Scoliosis.

There are four natural curves in the spinal column. The cervical, thoracic, lumbar, and sacral curvature.

Figure 1 – A and B. Normal lordosis is the two forward curves seen in the neck (cervical spine) and low back (lumbar spine). Normal kyphosis is the two backward curves seen in the chest (thoracic spine) and hip areas (sacral spine).

The spine curves in the following ways: The cervical spine curves slightly inward, sometimes described as a backward C-shape or lordotic curve. The thoracic spine curves outward, forming a regular C-shape with the opening at the front—or a kyphotic curve.

Scoliosis is another type of disorder identified by abnormal curvature of the spine. Each of these disorders is defined below. Lordosis is defined by an excessive inward curve of the spine. Although it primary affects the lumbar spine, it does occur in the neck too.

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.