If you or a loved one has experienced a spinal cord injury, it is important to narrow down the area of your injury, as well as the type of injury. Not all spinal cord injuries are the same. This is because the anatomy of the spinal cord is broken up into four different sections. These basic sections affect different parts of the body. The first step in diagnosing a spinal cord injury is determining which part or parts of the spinal cord has been effected. This will help a doctor determine what type of injury you or a loved one has sustained. On this page, I will review the four regions of the spinal cord in greater detail. These regions are the sacral spine, the lumbar spinal cord, the thoracic spinal cord, and the cervical spinal cord.
The Sacral Spine
The sacral spine is the lowest portion of the spine on the human body. It is comprised of the triangle-shaped area of the lower spine and it contains five vertebrae. These vertebrae bend slightly outwards, in contrast to the vertebrae of the lumbar spinal cord, which bend slightly inwards. Unlike the other sections of the spine, the sacral spine is not referred to as a cord because it actually does not contain a spinal cord. Instead, it consists of nerve roots that leave the spine at different vertebral levels. Damage to this area is less common than damage to other parts of the spinal cord.
The sacral spine is in charge of nerve communication in the lower body, which are controlled by the segments S1-S5. Trauma to the sacral spine affects feeling and movement in the lower body. Which parts of the lower body are affected depend on the specific segment effected. For example:
- SI controls the groin and hip
- S2 affects a person’s thighs and back
- S3 controls the medial buttock
- S4 and S5 affect the area surrounding the perineal or the genitals
The Lumbar Spinal Cord
Located above the sacral cord is the lumbar spinal cord. It is the lowest portion of the spinal cord compared to the thoracic and cervical spinal cord. It is located at the area where the spinal cord starts to bend, as mentioned in the previous section. Like in the sacral cord, there are five vertebrae in this section. These vertebrae are referred to as L1-L5. These vertebrae contain nerves and spinal cord tissue that provide communication between the legs and the brain. Subsequently, injury to the lumbar spinal cord will impact function of the lower body, sometimes as far up the body as the lower abdominal area.
A doctor may diagnose a lumbar spinal cord injury as complete or incomplete. The more “complete” the injury is, the more serious the prognosis is. While lumbar spinal cord injuries are serious, they are generally not as serious as injuries to other areas of the spinal cord. Many people with trauma to the lumbar spinal cord face muscle weakness, but are still able to take care of themselves and even walk short distances. Early diagnosis of the injury and physical therapy can help reduce the severity of this injury. In addition, trauma to this part of the spinal cord can affect both sides of the body or just one side.
The Thoracic Spinal Cord
Continuing to move up the spinal cord, you will find the thoracic spinal cord. This region takes up the middle part of the spinal cord. It contains 12 vertebrae, T1-T12. These vertebrae are recognizable by their rib shape. They affect different parts of the body as follows:
- TI is in charge of flexing the wrist and controls the forearm (medial side)
- T2 affects the posterior aspects of the upper arms
- T3 affects the chest (pectoral region)
- T4-T8 control the other muscles in the trunk of a person’s body and their chest
- T9-T12 are considered transition vertebrae because they are located closer to the lumbar spinal cord. Because of this, they can affect the lower body.
Much like with the lumbar spinal cord, injuries to the thoracic spinal cord can be serious, but are rarely life-threatening. Injury can be complete or incomplete, and it can affect one or both sides of the body. An early diagnosis and treatment are critical in minimizing the impact of an injury to the thoracic spinal cord. Many people with this type of injury are still independent and capable of taking care of themselves, although paralysis is possible.
The Cervical Spinal Cord
The cervical spinal cord is the topmost area of the spine. It connects a person’s neck to their back, and the brain to the spinal cord. There are eight vertebrae in this region, known as C1-C8. As you might guess, the C1 vertebrae is located at the top, and the vertebrae descend down the cord from there.
- C1 and C2 support a person’s head and allow it to move. Injury to the C1 and/or C2 vertebrae are the most severe of any spinal cord injury. Trauma to this area can result in full paralysis of the body and even death.
- C3, C4, and C5 vertebrae are located in the neck. Injury to the C3 vertebrae affects extension and flexion of the head. Injury to the C4 vertebrae affects the diaphragm. Injury to the C5 vertebrae affects muscles in the upper arms and a person’s vocal cords.
As already mentioned, injury to the cervical spinal cord can be very serious. These injuries are generally considered the most severe of injury to any region in the spine. Once again, early action is critical in helping these patients.
Getting Help
If your loved one experienced a spinal cord injury, this page should give you some basic information regarding where their injury is located. See my page, “Types of Spinal Cord Injuries” for a more detailed explanation of specific types of injuries. No doubt this is a very difficult time for you and your family. Please continue to use this site as a resource, and feel free to reach out to me with any questions.
