Kyphosis, also referred to as humpback or hunchback, is an excessive posterior curvature of the thoracic region. This can develop when osteoporosis causes weakening and erosion of the anterior portions of the upper thoracic vertebrae, resulting in their gradual collapse Figure 6.
Lordosis, or swayback, is an excessive anterior curvature of the lumbar region and is most commonly associated with obesity or late pregnancy. The accumulation of body weight in the abdominal region results an anterior shift in the line of gravity that carries the weight of the body.
This causes in an anterior tilt of the pelvis and a pronounced enhancement of the lumbar curve. Scoliosis is an abnormal, lateral curvature, accompanied by twisting of the vertebral column. Compensatory curves may also develop in other areas of the vertebral column to help maintain the head positioned over the feet.
Scoliosis is the most common vertebral abnormality among girls. The cause is usually unknown, but it may result from weakness of the back muscles, defects such as differential growth rates in the right and left sides of the vertebral column, or differences in the length of the lower limbs.
When present, scoliosis tends to get worse during adolescent growth spurts. Although most individuals do not require treatment, a back brace may be recommended for growing children. In extreme cases, surgery may be required. Osteoporosis is a common age-related bone disease in which bone density and strength is decreased. Watch this video to get a better understanding of how thoracic vertebrae may become weakened and may fracture due to this disease. How may vertebral osteoporosis contribute to kyphosis?
Within the different regions of the vertebral column, vertebrae vary in size and shape, but they all follow a similar structural pattern. A typical vertebra will consist of a body, a vertebral arch, and seven processes Figure 6.
The body is the anterior portion of each vertebra and is the part that supports the body weight. Because of this, the vertebral bodies progressively increase in size and thickness going down the vertebral column. The bodies of adjacent vertebrae are separated and strongly united by an intervertebral disc. The vertebral arch forms the posterior portion of each vertebra. It consists of four parts, the right and left pedicles and the right and left laminae.
Each pedicle forms one of the lateral sides of the vertebral arch. The pedicles are anchored to the posterior side of the vertebral body. Each lamina forms part of the posterior roof of the vertebral arch. The large opening between the vertebral arch and body is the vertebral foramen , which contains the spinal cord.
In the intact vertebral column, the vertebral foramina of all of the vertebrae align to form the vertebral spinal canal , which serves as the bony protection and passageway for the spinal cord down the back. When the vertebrae are aligned together in the vertebral column, notches in the margins of the pedicles of adjacent vertebrae together form an intervertebral foramen , the opening through which a spinal nerve exits from the vertebral column Figure 6.
Seven processes arise from the vertebral arch. Each paired transverse process projects laterally and arises from the junction point between the pedicle and lamina. The single spinous process vertebral spine projects posteriorly at the midline of the back. The vertebral spines can easily be felt as a series of bumps just under the skin down the middle of the back. The transverse and spinous processes serve as important muscle attachment sites.
A superior articular process extends or faces upward, and an inferior articular process faces or projects downward on each side of a vertebrae. The paired superior articular processes of one vertebra join with the corresponding paired inferior articular processes from the next higher vertebra.
These junctions form slightly moveable joints between the adjacent vertebrae. The shape and orientation of the articular processes vary in different regions of the vertebral column and play a major role in determining the type and range of motion available in each region.
In addition to the general characteristics of a typical vertebra described above, vertebrae also display characteristic size and structural features that vary between the different vertebral column regions. The lumbosacral joint is where the bottom of the lumbar spine l5 meets the top of the sacrum s1.
Below the sacrum is the coccyx, commonly known as the tailbone. The coccyx, like the sacrum, is a set of fused bones, though four bones make up the coccyx. It serves as an attachment point for a number of pelvic and hip tendons.
Another main purpose is the bear weight while seated. The sacral spine is stable compared to other regions of the spine, and is somewhat protected due to its position relative to the hips and pelvis. The most common injury to the sacrum and the coccyx is a fracture due to a fall. Additionally, sciatica will often arise due to the pinching of nerve roots at the lumbosacral joint.
The sacroiliac joints can become inflamed due to either too much or not enough range of motion. Fractures to the sacrum or the coccyx are rarely actively managed. Rest is usually the main form of treatment for one of these fractures, though decompression surgery may be required if nerves are affected. The facet joints have a strong, outer joint capsule.
The upper portion of the spine is called the cervical spine, and is composed of 7 vertebrae. Except for the 1st and 2nd cervical vertebrae, all vertebrae have three joints at each level, an intervertebral disc in the front and two facet joints in the back.
The cervical spine is extremely flexible, and therefore is quite prone to injury. The cervical spine also has small openings on each side the spine, for a special blood vessel carrying blood to the brain, called the vertebral artery. The middle portion of the spine is called the thoracic spine, and is composed of 12 vertebrae. The thoracic vertebrae are firmly connected to the ribs and breastbone sternum. There is very little movement or bending of the thoracic spine, and because of this, the thoracic spine is very strong and typically resists injury.
The lower portion of the spine is called the lumbar spine, and is composed of 5 vertebrae. There is significant flexion and extension movement in the lumbar spine, but minimal rotation.
Understandably, the lumbar spine is the most commonly injured region of the spinal column.
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