The lumbar vertebrae are located between the thoracic vertebrae and pelvis. They form the lower part of the back in humans, and the tail end of the back in quadrupeds. In humans, there are five lumbar vertebrae. The term is used to describe the anatomy of humans and quadrupeds, such as horses, pigs, or cattle. These bones are found in particular cuts of meat, including tenderloin or sirloin steak.
>>>PUT SHARE BUTTONS HERE<<<
π Lumbar spine in the context of Lordosis
Lordosis is historically defined as an abnormal inward curvature of the lumbar spine. However, the terms lordosis and lordotic are also used to refer to the normal inward curvature of the lumbar and cervical regions of the human spine. Similarly, kyphosis historically refers to abnormal convex curvature of the spine. The normal outward (convex) curvature in the thoracic and sacral regions is also termed kyphosis or kyphotic. The term comes from Greek lordosΒ 'bent backward'.
Lordosis in the human spine makes it easier for humans to bring the bulk of their mass over the pelvis. This allows for a much more efficient walking gait than that of other primates, whose inflexible spines cause them to resort to an inefficient forward-leaning "bent-knee, bent-waist" gait. As such, lordosis in the human spine is considered one of the primary physiological adaptations of the human skeleton that allows for human gait to be as energetically efficient as it is.
In this Dossier
Lumbar spine in the context of Kyphosis
Kyphosis (from Greek ΞΊΟ ΟΟΟ (kyphos)Β 'hump') is an abnormally excessive convex curvature of the spine as it occurs in the thoracic and sacral regions. Abnormal inward concave lordotic curving of the cervical and lumbar regions of the spine is called lordosis.
It can result from degenerative disc disease; developmental abnormalities, most commonly Scheuermann's disease; Copenhagen disease, osteoporosis with compression fractures of the vertebra; multiple myeloma; or trauma.
Lumbar spine in the context of Spinal canal
In human anatomy, the spinal canal, vertebral canal or spinal cavity is an elongated body cavity enclosed within the dorsal bony arches of the vertebral column, which contains the spinal cord, spinal roots and dorsal root ganglia. It is a process of the dorsal body cavity formed by alignment of the vertebral foramina. Under the vertebral arches, the spinal canal is also covered anteriorly by the posterior longitudinal ligament and posteriorly by the ligamentum flavum. The potential space between these ligaments and the dura mater covering the spinal cord is known as the epidural space. Spinal nerves exit the spinal canal via the intervertebral foramina under the corresponding vertebral pedicles.
In humans, the spinal cord gets outgrown by the vertebral column during development into adulthood, and the lower section of the spinal canal is occupied by the filum terminale and a bundle of spinal nerves known as the cauda equina instead of the actual spinal cord, which finishes at the L1/L2 level.
Lumbar spine in the context of Cauda equina syndrome
Cauda equina syndrome (CES) is a condition that occurs when the bundle of nerves below the end of the spinal cord known as the cauda equina is damaged. Signs and symptoms include low back pain, pain that radiates down the leg, numbness around the anus, and loss of bowel or bladder control. Onset may be rapid or gradual.
The cause is usually a disc herniation in the lower region of the back. Other causes include spinal stenosis, cancer, trauma, epidural abscess, and epidural hematoma. The diagnosis is suspected based on symptoms and confirmed by medical imaging such as MRI or CT scan.
Lumbar spine in the context of Bone mass
Bone density, or bone mineral density (BMD), is the amount of bone mineral in bone tissue, measured as mass of mineral per volume of bone (relating to density). Clinically it is measured by proxy according to optical density per square centimetre of bone surface upon imaging. Bone density measurement is used in clinical medicine as an indirect indicator of osteoporosis and fracture risk. It is measured by a procedure called densitometry, often performed in the radiology or nuclear medicine departments of a hospital or clinic. The measurement is painless and non-invasive with low radiation exposure. Measurements are usually made over the lumbar spine and the upper part of the hip. The forearm may be scanned if the hip and lumbar spine are not accessible.
There is a statistical association between poor bone density and a higher probability of fracture. Fractures of the legs and pelvis due to falls are a significant public health problem, especially in elderly women, leading to substantial medical costs, inability to live independently, and even risk of death. Bone density measurements are used to screen people for osteoporosis risk and to identify those who might benefit from measures to improve bone strength.