Lumbar (L1-L5) Spinal Cord Injuries
Injuries to the lumbar spine are severe but not life-threatening. Early treatment
is important to the prognosis.
As a fetus, vertebral segments directly relate to spinal cord segments. As an adult, the spinal column grows longer than the spinal cord and they no longer relate to one another. The spinal cord ends around the L1 or L2 vertebrae in adults, forming the conus medullaris. The horsetail shaped area, which extends past the conus medullaris, is called the cauda equina.
How many vertebrae are in the spine? Well, for the lumbar spinal column, there are five sections.
Lumbar vertebrae anatomy is generally classified by dividing the lumbar spine into five distinct sections. These sections are labelled as the L1-L5 vertebrae. These vertebrae are located near the base of the spine and naturally form a slight outward curve in the back, just below the inward curve of the thoracic spine. The lumbar vertebrae function to contain and protect the end of the spinal cord, as well as support the weight of the torso.
Here’s a quick explanation of how the lumbar spinal cord fits in with your lower back anatomy, as well as potential symptoms of injuries do different parts of the lumbar spine.
The L1 vertebra is the topmost section of the lumbar spinal column. This section of the spine contains a portion of the spinal cord. Injuries to the L1 spine can affect hip flexion, cause paraplegia, loss of bowel/bladder control, and/or numbness in the legs.
The L2 vertebra contains the end of the spinal cord proper—all other spinal vertebrae below this point only have spinal nerves, not the spinal cord. Injuries to the L2 vertebra can have effects similar to an L1 injury (reduced hip flexion, paraplegia, and numbness).
This is the middle vertebra of the lumbar spine, and the first vertebra to not contain a section of the spinal cord. Common symptoms of an L3 lumbar spinal injury include weakness, numbness, and loss of flexibility in the legs, hips, and/or groin.
The second to last section of the lumbar spinal column. While injuries to the L4 vertebra tend to be less severe than injuries to the spinal cord proper, symptoms include an inability to bend the feet in a particular direction.
The L5 vertebra is the final section of the lumbar spine (at least, it is for most people). Injury to the L5 spinal nerve bundle can cause numbness and weakness in the legs, but the extent of these symptoms can vary from case to case.
While most people have only five lumbar vertebrae, there are cases where someone could have an extra lumbar vertebra. This is called lumbarization. It is usually the result of the first and second parts of the sacrum failing to fuse, creating an extra bone in the spinal column.
In the majority of cases, this condition is harmless. However, some people who live with lumbarization may experience lower back pain without knowing why, or may be more prone to herniated discs in their spine.