When I see runners in the clinic, they tend to move into two categories as they age. One group can still run, and the other gets bitten by injuries and stops running. So what causes running knee pain, and how can you increase your odds of being in that group that can still run past middle age? Let's review.
Common Injuries Leading to Running Knee Pain in Middle Age
If you’re a runner, you know that injuries do occur. While middle-aged runners might be more at risk for running injuries, they can occur at any age, and leaving them unchecked, even if you’re young, can only lead to more problems later. Knee pain is very common when injuries do happen, and while the injuries can be due to a knee issue, they can be caused by other areas as well. Let’s take a look at a couple of common injuries that can cause running knee pain. First, we'll start with things outside the knee joint that can cause knee problems, and then we'll zero in on the knee.
Low Back or Hip Injury
If your running knee pain is centered in your kneecap (the patella), a common running complaint, this could be a sign that there is an injury in the low back or the hip. You may or may not have pain in your back or hip as it may only be presenting in the knee.
If you do have discomfort or tightness in your back after you run, however, this can be a sign that the multifidus muscles have stopped working due to nerve irritation. These muscles stabilize the backbones. When the multifidus is off-line, other muscles will jump in to try to stabilize the back. The problem with this is that these substitute muscles aren't designed for the job, and this can cause not only tightness but also spasms in the muscle. Learn more about your multifidus in my brief video below:
As for the hip’s impact on the knee, gluteal muscles that are weak or slow to activate have been shown, particularly in women, to overstress the kneecap. The gluteal muscles work in collaboration with the quadriceps muscles in the legs to provide support every time your leg impacts the ground as you run. If the gluteal muscles, which live in the hip area, are slow to fire, the quadriceps in the leg overcontracts. This causes the kneecap to be pulled with too much force, which, over time, wears down the knee cartilage.
Ankle Ligament or Tendon Injuries
Ligament or tendon injuries can cause running knee pain. The ankle, being the first big joint structure to absorb the impact of the ground, can become injured due to ankle ligament instability. So if your knee pain is also accompanied by sore ankles during or after running, or even with walking, ligament instability should be considered. Why would this affect your knees?
An injury to the ankle can alter how running forces are distributed as they move up the leg, either causing the next joint in the kinetic chain, the knee, to absorb more of the ground impact or to alter its biomechanics to deal with the force in an unnatural way. So an ankle injury can result not only in running knee pain but also, if left unchecked, knee arthritis, especially as you approach and enter middle age. More on ankle ligament instability in my video below:
What Can Happen in the Knee?
The knee consists of ligaments, tendons, the meniscus, bone, and cartilage. Injury to any of these structures could cause problems. Let's dig into each of these:
Ligaments: These structures act like duct tape that holds the knee bones together. There is the ACL, PCL, MCL, LCL, and ALL. If one or more of these are injured or just become loose due to wear and tear, your knee may feel unstable (shifts, pops, and clicks). This can lead to extra injury to the cartilage surfaces, meniscus, bone, and so on. Hence, making sure that these areas of ligament laxity are found early and treated is critical. However, realize that the average orthopedic surgeon won't usually look for these knee-wrecking instabilities, as he or she is looking for ligament injuries that can be operated. Instead, these lax ligaments can often be treated with a precise injection of specific substances or platelet-rich plasma (PRP) to heal and tighten them. Here's a video that shows how loose ligaments can harm your knees:
Tendons: There are a slew of tendons that insert in and around your knee that can become painful and torn up with running. These include the hamstrings on either side (biceps femoris on the outside and semimembranosus/semitendinosus on the inside), the pes anserine tendons on the inside front, the popliteus in the back and outside, the ITB on the outside front, and, finally, the quadriceps in the front. One or more of these can become overloaded and experience excessive wear and tear as you age. Treatment here is almost always not surgical but usually centers around precise injections using ultrasound guidance with platelet-rich plasma (PRP) into the bad areas. Here's a video that shows how pain in the back of the knee may be from a tendon:
Meniscus: The meniscus in the knee acts as a shock absorber and protects the cartilage. It also provides some stability for the joint. While one of the more common issues detected on MRI is a meniscus tear, the problem with that diagnosis is that these tears are common as we age. In fact, some researchers have compared meniscus tears to wrinkles, meaning that just because your knee hurts and someone finds a meniscus tear doesn't mean you need knee surgery. It's more likely than not that the meniscus tear was there long before your knee began hurting. Finally, surgery for most meniscus tears doesn't work, as evidenced by multiple large studies.
Again, here, we can often treat these small tears (if they're causing problems), through precise ultrasound guided injections of PRP or your own stem cells. Watch my video below if you have an MRI CD sitting around and you want to be able to see where your tears are located:
Bone and Cartilage: I include these here together because more and more research is showing that they are, in fact, the same tissue, just specialized to do one job more than the other. Cartilage lives on the ends of the knee bones and provides cushioning. The bone provides strength and impact resistance to the joint. One of the more common running injuries is that the cartilage wears down or is torn, which leads to swelling in the bone. Since cartilage doesn't have pain receptors, it's the bone swelling part of the injury that hurts. While small holes in the cartilage can sometimes be helped surgically, larger lost areas can't be helped with anything short of a knee replacement. However, we, again, often treat these issues with precise injections of stem cells or PRP. Check out my video below for some of the before and after MRIs of patients with cartilage issues treated with our specific Regenexx protocol:
Four Key Steps to Running as You Age
Of all of the advice I can give you, there are four key things to be able to continue to run as you age:
1. Keep your weight under control. This one would seem obvious, but less weight means less stress on joints and better control of the natural inflammatory repair response in the knee.
2. Listen to your body. The "no pain, no gain" mantra pushed by Jane Fonda ended up in multiple joint replacements for Jane. So if your body feels too beat up to run one day, then take that day off!
3. Be proactive! The key is to proactively address running injuries as they occur so they don’t become much bigger issues in middle age and beyond. Running knee pain may be your first warning sign that there's an injury that needs to be addressed, and finding that injury, whether it’s in the back, hip, ankle, or knee itself, early is imperative to protecting your knee from further injuries, such as arthritis. To read more about being proactive as you age, take a look at my book on the topic below:
4. Avoid knee surgery! Only a fraction of runners who get knee surgery really need it, as there are usually nonsurgical, injection-based procedures that use your own platelets or stem cells that can solve many painful problems without surgery. However, once the damage has been done by the first surgery, I often see runners get a second and then a third and then be told they need a knee replacement and that running is now off the table.
The upshot? You can run in middle age and beyond; however, like anything else in life, you need to play your cards the right way. I hope I've given you some sense of the best ways to see what's wrong and get the right diagnosis. In addition, I also tried to provide some advice on the best ways to avoid the traps that sideline many middle-aged runners!