For runners, low back pain is a common problem. According to Concong et al, 13.6% of recreational runners in the southern United States report experiencing back pain and about 85-90 % of the general population have experienced low back pain at some point in their life.
I personally experienced a very bad bout of sharp back pain at mile 22 of my 2015 marathon, and in that instant I thought "my body is tired, my core muscles are not holding me up." We all have to keep in mind that running requires a lot of strength in order to tolerate immense repetitive stress. Our spine and legs have to work really hard to propel us forward not to mention that our backs alone have to tolerate weight 3x that of our own for miles! Therefore, it is clearer to see how back pain can develop if our bodies are not conditioned for this immense stress.
Risk Factors for Low Back Pain:
There have been many studies that have looked at some traits that individuals with low back pain exhibit. There have not been many studies that have specifically analyzed low back pain in runners. However, despite the lack of research on runners, when we look at the demands of running it can be suggested that these general deficits can be far more harmful to runners.
On a lighter note, there have been studies that suggest that experienced or elite runners tends to experience less back pain. Which makes sense, these athletes have been conditioned for years! So, it make some sense as to why many beginners may be at risk for developing some low back pain vs. experienced runners.
Listed below are the top attributes that researchers have found in individuals who experience low back pain.
1. Decreased lumbar extensor muscle strength and endurance
There have been a few studies that have found low back pain subjects demonstrate lower values of lumbar extension (low back muscle) strength compared to the non-low back pain group, specifically in the lumbar multifidus.
The multifidi muscles are of the small yet powerful back muscles. They are a series of strappy muscles that originate at the spine and attach at each vertebral segment and some attach to the sacrum, and pelvis. When one side works these muscles helps rotate the spine and when both sides work these muscles extend the spine. When we run these muscles do play in role in helping rotate and counterrotate our trunks as we swing our arms and legs. Therefore, if these little abundant muscles are weak, our paraspinals will overwork.
It would be fair to also state that in 2006 study Renkawits et al found that both low back pain and non low back pain subjects demonstrates okay low back strength, however subjects with low back pain demonstrates neuromuscular imbalance or in other words poor coordination of the back and core muscles (6). Which means, these low back pain patients had some strength but had difficulty using them at the appropriate times. In our instance, a runner may have a hard time engaging their core when they move/run.
2. Delayed activation of the transversus abdominis-
There have been many studies that look at core strength and its correlation to back pain. Our core muscles primary function it to maintain spinal stability (aluko), and researchers have found that one of the major caused in general low back pain, especially chronic low back pain has been the significant decrease in core strength (wen-dien)- specifically the transversus abdominis.
The transversus abdominis is the corset of the spine and this muscle has 4 points of origin: the inner surfaces of the 7th to 12th ribs, iliac crest, thoracolumbar fascia, and the inguinal ligament. It inserts at the line alba ( center of the abs) and it works with the back muscles to stabilize the spine via intra abdominal pressure. This corset muscle helps rotate the the trunk to the same side, and when both sides work they help depress the ribs and create tension in the abdominal area. Poor poor muscle may also have a correlation to poor diaphragmatic breathing, which in turn causes excessive chest breathing which can also contribute to back pain. ( I can go into whole different topic which this so I will save it for a future post).
As mention before this is one of the core muscle that represent weak in patient who exhibit back pain, especially with a side plank (3). In 4 studies researchers took their low back pain subjects through a 6 week core strengthening regimen and after the strengthening program their low back pain subjects reported less pain and higher functional outcomes.
3. Weak glute maximus-
Our legs and spine both attach to our pelvises. Therefore, the role of the pelvis to stabilize both the trunk and lower extremities is very important. In a study conducted by Adams, researchers found that in subjects with low back pain the lumbo-pelvic muscles did not stabilize the spine as well as in individuals with no back pain. (1)
The major functions of the gluteus maximus during running are to decelerate the swing leg as we reach out with our foot and the glutes help power and extend the thigh back to. push off the ground. So if there is a power discrepancy in these hip muscles, something else was to take over, and that can be via the hamstrings and low back muscles. A weak gluteus maximus and medius will also allow the knee to drop inward and cause the opposite hip to drop and therefore strain the low back.
4. Stiffness of hip flexors
Lastly, another risk factor for back pain in runners can be tight hip flexors, which are the quads and psoas. Why may that be a risk factor, well both muscles attach at the hip and one of them goes as far as to attach to the lumbar spine. Therefore, if the muscles are stiff, you will be limited in hip extension during your push off during running gait and that will provoke excessive lumbar extension, which in turn causes more compressive stress at the back.
There was a study that looked at elite athletes and found that hip stiffness doesn’t correlate to back pain in athletes which is always good to keep in mind (5). I would go as far to say that stiffness itself may not be the sole cause to back pain, but more so that stiff hips actually inhibit the glutes for working as well as they should therefore lead to lumbar compensation. So, if you are stiff, I then would ask, how weak are your glutes. However, if hip flexor stiffness if pretty severe this for sure can provoke low back pain.
If you are a runner and are experiencing some sort of back pain, and do not work in any of these areas, it may be possible that you may demo some of these deficits.
Make sure to visit your local physical therapist for a more detailed assessment. Take care of it now before your symptoms get worse and affect performance.
I will be posting Part II: Training and Strengthening for Low Back Pain next. Stay tuned.
Remember
- TRAIN SMART AND RUN HAPPY!
Your team-mate,
JESSICA MENA PT, DPT, CSCS, RUNNER.
REFERENCES:
1. Adams MA. Biomechanics of back pain.
Acupunct Med. 2004 Dec; 22(4):178-88.
2. Aluka A, DeSouza L, Peacock J. “The effect of core stability exercises on variations in acceleration of trunk movement, pain, and disability during an episode of acute nonspecific low back pain: a pilot clinical trial.”Journal of Manipulative Physiol. Therapy 2013 Oct;36(8):497-504.e1-3. doi: 10.1016/j.jmpt.2012.12.012. Epub 2013 Aug 12.
3. Evans K, Refshauge K, Adams R., Aliprandi L, “Predictors of low back pain in young elite golfers: a preliminary study,” Physical Therapy in Sport, vol. 6, no. 3, pp. 122–130, 2005
4. Kujala U.M, Taimela S, Oksanen A, Salminen J.J, “Lumbar mobility and low back pain during adolescence. A longitudinal three-year follow-up study in athletes and controls,” American Journal of Sports Medicine, vol. 25, no. 3, pp. 363–368, 1997.
5. Nadler S.F, Wu K.D , Galski T, Feinberg JH. “Low back pain in college athletes. A prospective study correlating lower extremity overuse or acquired ligamentous laxity with low back pain,” Spine, vol. 23, no. 7, pp. 828–833, 1998
6. Renkawitz T, Boluki B, Grifka J, “The association of low back pain, neuromuscular imbalance, and trunk extension strength in athletes,” Spine Journal, vol. 6, no. 6, pp. 673–683, 2006.
7. Vahideh M, Memari AH, ShayesterhFar M, Kordi R Low Back Pain in Athletes Is Associated with General and Sport Specific Risk Factors: A Comprehensive Review of Longitudinal Studies Rehabilitation Research and Practice, 2015 (2015), Article ID 850184, 10 pages