What Your Knee Pain While Running Means — And What to Do About It
How to decode and deal with four types of knee aches that are super-common among runners.
First of all, let’s get this out of the way: No matter what you might have heard before, running isn’t bad for your knees.
“That has been completely disproven,” says Dr Jordan Metzl, primary sports medicine physician at the Hospital for Special Surgery in New York City. In fact, arthritis — a common source of knee pain — was seen in only 3.5 percent of recreational runners in a 2017 literature review published in the Journal of Orthopedic Sports Physical Therapy, compared with 10.2 percent of sedentary non-runners. Some research has even suggested that continued recreational running can have a protective effect on the joint by thickening cartilage in the knee over time.
That being said, “knee pain in runners is quite common, and it’s important to recognise the problem and fix it because it can change the way you run or if you run at all,” says Metzl. “It can change your running mechanics and lead to other injuries.”
Bad running mechanics or overtraining can lead to injury, but “running itself is not the issue,” agrees Cathlin Fitzgerald, senior physical therapist at Custom Performance. “But of course, like with any sport or activity, you can overdo it.”
Keep reading for more about four common sources of knee pain while running, with expert advice about how to ease the aches so you can keep up your running routine — or get back to it ASAP.
If you have pain below your knee, toward the shin
It could be: patellar tendonitis
What it is:
The patellar tendon is the band of connective tissue that runs from your kneecap to your tibia (or shin bone). With patellar tendonitis, the tendon becomes weak, inflamed, and painful to the touch. It tends to happen with greater mileage or a lot of downhill running, especially in cross-country runners or people doing longer distances without enough strength training targeted at their quads, says Metzl. The quads provide the breaking mechanism as you run downhill, so if they’re not strong enough to withstand the strength and stability needed, it could lead to pain.
Metzl also says the patellar tendon is part of the extensor mechanism of the knee, along with the quads, quadricep tendon, and kneecap, which are all involved whenever you extend your knee. When the quad is weaker, it can end up putting more stress on the tendon during that extension.
Tightness (not just weakness) in the quads can also contribute to knee pain from patellar tendonitis.
“For tendonitis, initiating movement is usually the most painful, and it lessens as the tendon warms up — but then the pain comes back after activity,” says Fitzgerald.
What to do about it:
You’ll want to see a physiotherapist or a doctor to avoid getting chronic tendinopathy, especially if it doesn’t go away after several weeks.
Fitzgerald recommends “flossing” the distal quad to help address the aches as soon as they pop up. Here’s how: Place a tennis ball just above the kneecap while lying face-down. Keeping some bodyweight through that leg with pressure on the ball, bend and straighten the knee five to 10 times.
If you have pain underneath your kneecap
It could be: patellofemoral pain syndrome
What it is:
The typical victim of this ache is clear from its nickname: runner’s knee. It’s an irritation of the cartilage under the kneecap and it’s especially common in runners with foot mechanical problems and/or insufficient strength in the muscles above the knee, including the quads, glutes, hips, and core, says Metzl.
In fact, glute weakness or fatigue or general lack of activation of the glute muscles is often the biggest culprit for patellofemoral pain syndrome, says Professor John Vasudevan, associate professor of clinical physical medicine and rehabilitation at the University of Pennsylvania and co-director of the Penn Medicine Running and Endurance Sports Program.
He often uses a single-leg squat to assess if you need to strengthen these muscles. As you perform the move in the mirror without shoes, check to see if the opposite hip to your standing leg drops, the knee moves toward the midline, or there’s a flattening of your arch. If so, it’s time to build up the backside.
The alignment of your knee often comes into play with runner’s knee too, says Fitzgerald: Many of her patients with runner’s knee have a kneecap that’s higher, more inside, or more mobile than most.
Like patellar tendonitis, patellofemoral pain syndrome (or PFPS) is more prevalent in those logging lots of downhill kilometres(and not doing enough strength training); unlike tendonitis, the pain tends to be under the kneecap itself, not in the tendon below it — causing a dull, aching pain that can worsen with going down stairs, squatting, or prolonged sitting. “It generally does not swell,” says Metzl, “so if you’re getting swelling, there’s something else going on and it’s important to get that checked out.”
What to do about it:
Taking an anti-inflammatory can help the pain subside temporarily, while the longer-term treatment is lower-body strength-training concentrated on the glutes and quads, says Metzl. Exercises like weighted squats and deadlifts can strengthen these muscle groups to help you sidestep pain, along with exercises that specifically target the gluteus medius, as one meta-analysis of studies found a link between weakness in this specific muscle and runner’s knee. Banded exercises, like side steps and monster walks, are particularly good for strengthening the gluteus medius.
A physical therapist can suggest exercises for strength and to improve your hip and kneecap mobility (typically addressed via manual therapy techniques performed by a physiotherapist or biokineticist) and running mechanics. Fitzgerald again recommends flossing your distal quad to help with this patellofemoral ache; see above for how to try it.
If you have pain toward the outside your knee
It could be: IT band syndrome
What it is:
IT band syndrome means you have inflammation in the iliotibial band, a thick band of connective tissue that runs from the hip to below the knee. When your glutes— particularly the gluteus medius — aren’t strong enough, the IT band tends to start rubbing on the outside part of the knee. And that tendon gets exceptionally sore.
“After about a kilometre of running, it’ll start feeling like someone is taking a screwdriver and jabbing it in the side of the leg,” says Metzl. “It’s very distinctive, it’s very sharp, and you feel like you can’t go on anymore. It’s extremely painful.”
What to do about it:
Talk to a physiotherapist sports doctor, advises Metzl. “You want to stop the pain cycle as quickly as possible,” he says. “It’s very difficult to run through this, and when this becomes a chronic problem, it’s challenging to get rid of.”
In the meantime, some foam rolling on the side of your upper leg and shortening your stride while you run can help, but mostly, you’ll want to up your lower-body strength with lots of squats and lunges.
Fitzgerald also recommends opening the front of the hip, by stretching your quads and hip flexors, and strengthening the gluteus medius with some simple band exercises like side steps.
Your physician might recommend cortisone shots — Metzl says he typically recommends these when the pain lasts more than a couple months or if it’s so severe it changes the way you run — or suggest you take a break from running.
If you have pain toward the inside your knee
It could be: knee arthritis
What it is:
Simply put, the word arthritis means inflammation in a joint. There are several kinds, but osteoarthritis (the most common in runners) can be due to a previous injury, genetics, or just bad luck with your cartilage. A wearing down of cartilage in the knee causes your bones to start rubbing together, causing pain. It feels like a dull achiness during and after running “like a toothache that won’t go away,” says Metzl. You may also notice swelling.
While arthritis can show up anywhere around the knee, it’s one of the more common causes of pain on the inside of the joint.
What to do about it:
You can take some anti-inflammatories to lessen the pain on your own, but a doctor will perform a physical exam and take X-rays to assign your arthritis a stage, or grade, and determine proper treatment.
Your doctor might suggest platelet-rich plasma (PRP) injections, says Metzl. During PRP, your doc takes blood from your arm, spins it to isolate the platelets, combines it with a lubricant, and injects it into the knee.
Combining PRP with hyaluronic acid (lubricant) injections may also work for some runners with osteoarthritis, Metzl says: “We used to think arthritis was just the mechanics of the bones grinding, but we’ve realised there’s an inflammatory component to that as well. The lubricant works on the mechanics piece, and the PRP is essentially like a natural, long-acting cortisone, which works on the inflammatory part of the osteoarthritis.”
PRP is often not covered by insurance, though, Vasudevan adds, and both PRP and lubricant are part of emerging science on how to manage arthritis. He says in some cases, corticosteroid injections may also be the way to go.
Along with in-office treatment should come lots of strength training. Aim for three times a week, advises Metzl, focusing on the quads, hamstrings, and glutes.
The Takeaway on Knee Pain While Running
It’s always a good idea to consult a physiotherapist or sports medicine doctor if you’re dealing with knee pain, and meds might be necessary. If you’re having persistent problems, a running or gait analysis can be very helpful too.
Above all, however, adding strength to the surrounding muscles is essential to combat any knee ache. Adding some plyometric moves is also beneficial, says Metzl, because “running is essentially a plyometric activity — you’re jumping from one leg to the other.” Try jump squats and jump lunges (if you can manage them with your achy knee) to help improve your single-leg power and stability.
Finally, it’s important to start getting stronger today, even if you don’t have knee pain or it’s intermittent. “If your knee is sore, it’s difficult to add strength, and then you usually get more quad atrophy,” says Metzl. “Then if the quad gets weaker, the knee pain gets even worse. It’s kind of an unhappy alliance.”
Take a break when you need it to help your knee pain subside — and turn to cross-training activities with lateral movements, if that feels good for you in the meantime or even when you are running. Then, when you can add in strength work, know you’ll be working to ease your current ache and help prevent future injuries, too.
