Dissecting Low Back Pain: Lumbar Sprain/Strain

The most common reason to have low back pain is a lumbar sprain/strain injury. You may have heard of this type of injury referred to as a pulled muscle or ligament. The complex combination and mechanics of muscles, tendons, and ligaments help support the lower part of the spine (lumbar spine), hold up and support the weight from the upper body. Injury happens when the muscles and/or ligaments undergo too much load or stress that they are unable to endure. In case of a lumbar strain injury it is the muscle that gets injured when the muscle fibers are abnormally stretched or torn. In a lumbar sprain the ligaments that hold the lumbar vertebral bones together are torn either due to sudden injury or due to gradual overuse.

Why does lumbar sprain/strain injury happen?

As mentioned above these injuries typically result due to sudden violent muscular contraction during an excessively forceful muscular stretch from lifting heavy objects or sudden twisting motions. Most patients will recall a specific inciting even like lifting and moving something heavy like a couch, refrigerator, heavy boxes, luggage, etc. Others though may not recall what may have caused it. Other reasons for sprain/strain does not have to be a sudden injury but rather can be due to repetitive movements. For instance, repetitive and prolonged bending, twisting, or rotating movement of lower back like in tennis, golf, or in daily chores like sweeping, raking leaves, or gardening can result in a lumbar sprain/strain injury.

What kind of symptoms are expected?

Low back pain is common and expected. Pain can radiate, even to the buttocks and sometimes even down the thighs. There should however be no pain that radiates past the knees, which is a sign of a more severe injury. Stiffness and restricted range of motion of the lower back is also common. This can make it difficult to hold certain positions (standing, sitting, bending, etc) due to the stiffness and pain.

Pain will typically resolve within 10-14 days. Seek medical opinion if pain lasts longer then 6 weeks or is getting progressively worse. Lumbar sprain/strain injury will not present with any neurological symptoms like numbness, tingling, or weakness. There should also not be any loss or impairment of bodily function. These symptoms would not be due to lumbar sprain/strain and something more serious may be happening, seek medical care if these symptoms occurs.

How is this injury diagnosed?

This injury is diagnosed by a good and thorough history of the injury and a complete physical exam with focus on the neurological and musculoskeletal. With the exam and the history a physician can rule out any neurological or serious spinal injury and narrow down the diagnosis to a lumbar sprain/strain injury without need of any testing. In fact lumbar ligamentous strain or muscle sprain is a example of a condition that would not specifically show up on MRI or other imaging modalities. Sometimes what is seen on the imaging can actually lead to misdiagnosis and unnecessary treatment. Therefore, in the absence of neurologic findings (eg, leg weakness) or pain persistent longer than 6 weeks, radiographic or MRI evaluation is rarely useful.

What is the recommended treatment?

For most, treatment may not be even necessary as sprain/strain injuries typically resolve on their own within a week or two. Slight rest from bending/twisting and lifting can help but full bed rest is not recommended as it can result in loss of muscle strength and may increase muscle stiffness, adding to pain and discomfort. Medications like NSAIDs (nonsteroidal anti-inflammatories, like ibuprofen) can help the pain and inflammation. Other medications that can help include Tylenol and muscle relaxants. Physical therapy can help with treatment as well as prevention of any future episodes by instructing and developing a home exercise program.

What is the prognosis for this injury?

Lumbar sprain or strain injury has a very favorable prognosis with a high likelihood of a complete recovery. Typically more than 90% of patients will make a complete recovery within one month.