5 Most Common Causes of Low Back Pain After a Car Accident
Welcome to today’s blog post on common low back injuries following car accidents, which are broadly referred to as motor vehicle accidents (MVAs). Low back pain is the most common complaint after a car accident and there are many potential causes. In this post, we will examine how common low back pain is after an accident, the anatomy of the low back, and the most common conditions that cause low back pain.
Prevalence of Low back Pain following Car Accidents
Before we look at the most common low back injuries, let’s look at an overview of how common low back pain is. One study performed on almost 100 individuals after MVAs found that 70% of individuals experienced low back pain. In addition, it was more likely that individuals with a history of medically-treated low back pain had a recurrence of low back pain compared to individuals with no history.
Anatomy of the Low Back
The low back, medically known as the lumbar spine, consists of 5 vertebrae, as well as the sacrum (also known as the tailbone) at the bottom. Between each set of vertebrae there is a disc, as well as two joints that allow the vertebrae to rotate and move; these are called facet joints. In addition, there are also nerves that come out between each segment of the low back and descend into the legs. These are called nerve roots and they play an important role in conditions like sciatica and low back pain.
In addition to knowing the structures involved in the low back, it is also important to understand how each structure is named. The vertebrae themselves are given a number based on their position, with the first (top) vertebrae being labeled L1, the second one L2, all the way down to the bottom one being labeled L5.
The facet joints and discs are labeled based on which vertebrae they are between. For example, if we are talking about the disc that is between L1 and L2, we call it the L1-L2, or L1-2, disc. The notable exception is the disc between the L5 vertebrae and the sacrum, which is called L5-S1.
Last but not least, the nerves are also labeled based on where they exit the spine. For example, the nerve coming out between L1 and L2 is the L1 nerve root, the nerve coming out between L2 and L3 is the L2 nerve root, etc. There are also nerves that come out of the sacrum, but these are less commonly injured since the sacrum is a very stable bone.
Below you will see a picture that outlines all of these structures.
5 Most Common Low Back Injuries Following a Car Accident
1. Sprains and strains
While sprains and strains are similar, they are not the same. A sprain refers to an injured ligament (tissue that connects from a bone to another bone), while a strain refers to an injured tendon (tissue that connects from a bone to a tendon). Sprains and strains are very common following car accidents, because the rapid force produced by a collision can stretch the tendons and ligaments beyond their typical capacity, causing tears within the tendons and ligaments. In low-velocity accidents (<30 mph), these tears are usually small and heal without surgery or injections.
2. Disc Herniation
When your body experiences a sudden, traumatic force from a MVA, it can put a lot of pressure on the discs, causing one or more to squish and press out of its location between the vertebrae. The most common directions for a disc herniation are backwards and slightly to the side (posterolateral), which is in the direction of the nerve roots, followed by directly backwards (posterior), which is towards the spinal cord. Most disc herniations are 2-4 millimeters in diameter but can extend to 8 or more millimeters is some cases.
In addition to pain in the low back, one of the most common presentations of a disc herniation is pain into the leg if the associated nerve is injured. Depending on where the pain in the leg is, this can be termed sciatica. It is important to note that if you begin to lose feeling in the leg or begin losing strength, you should see a healthcare practitioner for further evaluation. To learn more about disc herniations and how physical therapy can help, click here.
3. Facet Joint
When involved in a MVA, it is common for the facet joints to become compressed, resulting in a feeling of your back being “locked up.” The most common presentation of this type of injury is pain when extending your back or bending towards the side of the pain. This is because you are taking a joint that is already compressed and compressing it even further.
4. Nerve injury
I mentioned nerve injuries already under the Disc Herniation section. It is common for the nerve roots and/or the spinal cord to be injured in a car accident. This can occur due to pressure from a disc on the nerve, compression of the nerve between the two vertebrae, or simply due to irritation of the nerve by the chemicals involved in responding to the general injury in the low back region.
5. Muscle dysfunction
When your low back experiences a traumatic injury, such as a car accident, the muscles located deep in your back, next to your spine, can stop working properly. This dysfunction is compounded by the degree of decreased activity you experience as you heal from the accident. Research has found that this muscle dysfunction is more common in the lower levels of the spine, around L4-5 and L5-S1, and most commonly occurs when there is damage to the nerves in the area. In addition, another study found that individuals who did not perform exercise therapy following the onset of low back pain did not recover the use of these muscles as well as a group that did perform exercise therapy (shameless plug for physical therapy).
Western Slope Rehab and Performance is Here to Help
If you are struggling with injuries or have recently been in a motor vehicle accident, we can help. We are a physical therapy company that provides home-based orthopedic services in the Grand Junction, CO, area, as well as telehealth appointments throughout Colorado. If you would like to schedule a free consultation, you can call us as 970-462-9177, or fill out our contact form here.
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