What are Lumbar Disc Injuries and How Long Do they Take to Heal?
Low back disc injuries are one of the most common injuries a physio would see. Let's answer some of our most commonly asked questions about symptoms, healing and treatment.:
What are spinal discs?
What are the most common types of disc injuries?
How long does is take for a disc to heal?
How do I know if I've hurt a disc in my back?
How can physio help?
What are spinal discs?
The spine is made up of successive bony vertebrae, placed on top of each other. These vertebrae are separated by spinal discs, unique structures which functionally serve as the shock absorbers of the spine. They also allow for movement between spinal vertebrae and assist ligaments in maintaining the stability of the vertebral column.
How are they injured?
Degeneration: Aging causes degeneration of spinals discs. By losing some of their fluid, discs become relatively hard and flat. These changes do not typically cause pain and are a natural part of the aging process, highlighted by MRI findings showing degenerative changes in 37% of asymptomatic 20–30-year old’s (Brinjikji et al., 2014).
Repetitive microtrauma: Accumulated microtrauma commonly occurs through poor posture. The most prominent example of this, in the lower back (lumbar spine), is the sustained slouched posture often seen in sitting. Due to the anterior load of spinal discs consistently sitting in this flexed position, over time, causes discs to lose integrity, and can lead to them being displaced posteriorly.
Exposure to high loads: Spinal discs are most susceptible to injury when they are placed in positions with high sheering forces. This occurs in the lumbar spine when a heavy load is placed on the spine in end range flexion (bending), especially with additional twisting. Hence, it is essential that when lifting heavy items off the floor, it is done with proper lifting technique, by keeping the spine in a neutral position.
The above factors generally work in combination to cause an injury of a lumbar spinal disc. Due to the ligamentous structure of the lumbar spine; a disc herniation usually occurs near the posteriorly positioned spinal nerves (depicted below). If the disc material pushes against the spinal nerve, or inflammation from the disc irritates the nerve it can result in radiating pain down the leg, weakness, and numbness.
Disc injuries are not always painful:
It is important to understand that an injured spinal disc does not necessarily give us pain. Research shows that 30% of 20-30-year-olds and 84% of those aged over 80, who are asymptomatic (have no pain), have at least one herniated disc. Hence, it is important to remember that imaging techniques such as CT scans and MRIs cannot actually see pain, so treatment should be based on the individual’s symptoms, and assessment findings not the findings of imaging alone.
Symptoms of disc injuries:
Low back pain, particularly with activities that flex the lumbar spine, such as bending or sitting for a prolonged period
Pins and needles, numbness or shooting pain down one or both legs
Lower limb weakness
Leaning to one side to avoid pain
Relief with extending the lumbar spine
Mechanism: An increase in activities with repeated lumbar flexion (for example rowing training volume) or heavy lifting with a flexed lumbar spine
How can Physiotherapy help?
Evidence shows us that two thirds of lumbar disc herniations regress within 3 months- 1 year, with conservative interventions, such as physiotherapy (Zhong et al., 2017). Further, larger lumbar disc herniations were found to be more likely to regress, due to their increased exposure to the immune system (Chiu et al., 2014). Due to this high rate of regression of disc material, in most cases physiotherapy should be the first choice of treatment for lumbar disc injuries.
What can we expect from treatments?
Physiotherapy treatments are generally focussed on encouraging movements which will put the disc in the optimal position for healing. Some of these treatments include:
Taping, bracing and other assistive devices
The use of ice and non-medicated anti-inflammatory cream
Exercises that encourage regression of injured disc material
Exercise prescription to improve strength, flexibility, and movement patterns
The above treatment can generally be broken up into three phases:
Reducing acute symptoms of pain and inflammation
Restoring joint range of motion and muscle flexibility
Improving muscular strength, motor control and functional movement patterns to prevent reoccurrence
Benoist, M., 2002. The natural history of lumbar disc herniation and radiculopathy. Joint Bone Spine, 69(2), pp.155-160.
Brinjikji, W., Luetmer, P., Comstock, B., Bresnahan, B., Chen, L., Deyo, R., Halabi, S., Turner, J., Avins, A., James, K., Wald, J., Kallmes, D. and Jarvik, J., 2014. Systematic Literature Review of Imaging Features of Spinal Degeneration in Asymptomatic Populations. American Journal of Neuroradiology, 36(4), pp.811-816.
Chiu, C., Chuang, T., Chang, K., Wu, C., Lin, P. and Hsu, W., 2014. The probability of spontaneous regression of lumbar herniated disc: a systematic review. Clinical Rehabilitation, 29(2), pp.184-195.
Zhong, M., Liu, J., Jiang, H., Mo, W., Yu, P., Li, X. and Xue, R., 2017. Incidence of Spontaneous Resorption of Lumbar Disc Herniation: A Meta-Analysis. Pain P