Modern medicine has advanced significantly in the last century, meaning huge leaps forward in our understanding of our bodies and how their different systems work.
However, even with everything we know about our bodies now, there are still many mysteries in how they operate, and how certain systems link together. Unfortunately, this can lead to unnecessary treatments or surgical interventions – particularly when pain that presents in one area of the body is actually caused by issues in another part of the body.
Referred pain occurs when a problem in one place in the body causes pain in another place, after the pain travels down a nerve. For example, a pinched nerve in our backs can cause pain and other problems throughout our legs.
Referred pain needs to be correctly diagnosed to make sure it’s treated effectively. If you can learn to understand and recognise the links between your knee and back pain, you’ll be better able to identify the real source of your knee pain.
How are the knee and back connected?
Our knees and backs are connected by nerves – and the nerves that drive the muscles around the knees are actually in our backs. Occasionally, after injury or as we age, the discs between the vertebrae can bulge out and press on these nerves.
As a nerve becomes irritated, it will cause pain in a specific area of the body, depending on which disc is protruding. The nerves that send fibers to the knee are located at the second, third, and fourth lumbar vertebral levels in the lower back area. When one of the nerves in this area becomes irritated or damaged, referred pain will often be felt in the knee.
The signs that your knee pain is actually being caused by back issues include:
You experience knee pain accompanied by back pain
If you’re experiencing knee pain – either as a one-off occurrence or an ongoing problem, take the time to think about whether you’re experiencing pain anywhere else in your body. Even if the two seem unrelated, it’s worth noting the pain and discussing it with your spinal specialist.
Back pain causing knee pain is more common in people who sit a lot, so if you work a desk job or spend a lot of time in your car or on planes, it’s worth investigating. Remember, the back pain may not seem as severe as the knee pain – it may even just feel like tight muscles.
You’re getting bunions
We know, it sounds like a strange connection, but bunions can actually be a sign of underlying issues in your back. Bunions are caused by the big toe tilting to an unnatural angle, leaving space for ‘bone spurs’ (or bunions) to form. This angle of the toe is often caused by a weakening of muscles. There are nerves running from our backs to both the inside and outside of our feet. When one becomes irritated, it can affect the operation of the muscles in our feet and cause them to loosen. This leads to a tilting of the toe joint.
You’re feeling tightness in the hamstrings
If you’re stretching your hamstrings often to try and relieve pain or tightness- and finding that it’s not working – then there may be a nerve issue in your back causing trouble. The L5 nerve travels from the lumbar spine and down the outside hamstring muscle to power the biceps femoris. Issues with this nerve can affect the knee in two ways – directly, and through changing our movements if we’re dealing with long-term hamstring tightness.
You have hip or quadricep weakness
If you find that you’re experiencing a weakening hip, it may be a sign of issues with your spine. When problems in the spine cause your hip muscles to weaken, your knees may have to work harder to compensate – causing pain.
The issues above are common additional signs that your knee pain may actually be caused by issues in your back. However, even without them, it’s possible your knee pain didn’t actually originate from problems in your knee.
If you’re experiencing knee pain, it’s important to get to the real cause of your problem – particularly before you consider invasive procedures like surgery. All too often, knee pain is not the issue but a symptom of a problem somewhere else.
Talking to a physiotherapist or spinal specialist is a good way to get an assessment of how issues in your back may be causing knee pain.