3 Signs Your Back Is Causing Your Knee Pain
On this page:
- Can your back cause knee pain?
- How are the knee and back connected?
- What are the signs your back is causing your knee pain?
Just about everything you think you know about your knee pain is probably wrong. This is because so much of what you hear is based on a surgical and old-school impression of the musculoskeletal system.
Most physicians hold fast to what they learned in medical school, but the truth is, the science of medicine is constantly evolving, finding less invasive ways to treat our ailments, and discovering the root causes of our pain.
Can Your Back Cause Knee Pain?
An important thing to understand is that what hurts is not necessarily the problem, but a symptom of the problem. For knees, the first thing to consider if knee pain isn’t the result of traumatic injury is, are issues in your back causing your knee pain?
Not determining the root cause of your pain could sadly result in a shiny, new (and unnecessary) knee replacement that doesn’t actually address the source of your pain (1). And as we’ve seen in research studies, an unacceptably high percentage of patients still have chronic pain after knee replacement (2).
How Are the Lower Back and Knee Pain Connected?
Your back houses the nerves that drive the muscles around the knees. Hence, a problem with a nerve in your back can impact how those muscles work. Low-level nerve irritation usually isn’t noticed by patients as back or leg pain. It just causes the muscles to misfire, destroying the otherwise needed protection for the knee joint.
Given the importance of nailing down the actual source of your pain, you need to know the 3 signs that it could be your back causing your knee pain.
What Are the Signs Your Back Is Causing Your Knee Pain?
1. Lower Back and Knee Pain
If you have acute or chronic knee pain, mentally and purposefully scan for other pains or discomforts that accompany it. These pains or discomforts may seem completely unrelated, but consider them anyway.
Back pain can be related to knee pain simply based on the phenomenon of referred pain. The nerves to the lower extremities branch directly off the lower spine. So it’s easy to see how a pinched nerve, perhaps due to a bulging lumbar disc in the lower back, could direct pain down that nerve branch and into the knee.
If you sit a lot—maybe you travel for a living and spend a lot of time on airplanes, or maybe you have a desk job and don’t get up and move around like you should—sitting reduces the disc height and increases the disc bulge by pushing water out of the disc. So if you sit a lot, and you have both back and knee pain, it’s possible the knee pain is due to your back.
You might not even consider your back discomfort to be pain. It may just be a little tense or tight. It could be very mild, but don’t discount it. Before deciding on a major knee surgery, you owe it to yourself to have even the mildest back discomfort investigated to determine if it’s your back causing your knee pain.
2. Tightness in the Hamstrings
Ever see people in the gym every day using a foam roller to massage and relax their hamstrings? These people can never seem to get permanently rid of the tightness. If this is you, there’s a reason this is happening, and it’s not good for your knees.
The L5 nerve travels from the lumbar spine and down the outside hamstring muscle to power the biceps femoris. Hamstring pain or tightness that won’t go away despite repeated stretching is one of the first signs in the lower extremity that there could be a nerve issue in your back causing knee pain.
When the hamstrings become tight, painful, or inflamed, this will impact how the knee joint works (3). So not only is the knee affected directly by the nerve but also by the adjustments you might make in how you move to compensate for the stressed hamstring.
After a few weeks of hamstring tightness, the meniscus will begin to suffer and your body will attempt to repair it by mobilizing the stem cells in your knee and other inflammatory cells in the body. Since the trauma will be constant and ongoing, the cells’ efforts will be futile, and the swelling will live there until the root cause is addressed.
3. Bunion Formation
Bunions? Really? You might wonder what in the world bunions have to do with your back; however, bunions can be a direct result of back issues, and where there are bunions and back issues, there is probably knee pain.
When there’s a problem in the back, this can cause the stabilizing muscles of the foot to weaken and lead to bunions. The L5 spinal nerve goes to the muscles that help support the inside of the foot, while the S1 nerve goes to muscles that support the outside of the foot.
When the nerve is stressed or injured, the muscles that support the outside of the foot as you walk, run, or stand won’t be able to do their job. This will cause the foot to pronate, forcing a misalignment in the main tendon and leading to an unnatural tilting of the big toe joint. This tilting of the toe joint creates pressure in the joint, where bunions, or bone spurs, can form.
When you develop a bunion, it’s important to find its source. There’s a good chance your back is the culprit.
The upshot? It won’t do you any good if we just treat your knee pain with a knee stem cell injection if it’s an issue in your back causing your knee pain. It may provide some slight temporary relief, but it won’t fix your problem. Likewise, it won’t do you any good if a surgeon cuts out your knee and replaces it when the knee isn’t the true source of your pain (4).
To find out if you might be a candidate for a Regenexx procedure, complete our Regenexx Procedure Candidate Form online.
(1) Metsna V, Vorobjov S, Märtson A. Prevalence of anterior knee pain among patients following total knee arthroplasty with nonreplaced patella: a retrospective study of 1778 knees. Medicina (Kaunas). 2014;50(2):82-86. doi:10.1016/j.medici.2014.06.001
(2) Beswick AD, Wylde V, Gooberman-Hill R. Interventions for the prediction and management of chronic postsurgical pain after total knee replacement: systematic review of randomised controlled trials. BMJ Open. 2015;5(5):e007387. Published 2015 May 12. doi:10.1136/bmjopen-2014-007387
(3) Kumar D, Subburaj K, Lin W, et al. Quadriceps and hamstrings morphology is related to walking mechanics and knee cartilage MRI relaxation times in young adults. J Orthop Sports Phys Ther. 2013;43(12):881-890. doi:10.2519/jospt.2013.4486
(4) Kahn TL, Schwarzkopf R. Does Total Knee Arthroplasty Affect Physical Activity Levels? Data from the Osteoarthritis Initiative. J Arthroplasty. 2015;30(9):1521-1525. doi:10.1016/j.arth.2015.03.016