Patellofemoral pain syndrome, commonly just called “runner’s knee,” has been found to be one of the leading exercise-related injuries in adults — even more common than other running injuries like iliotibial band friction syndrome, plantar fasciitis, meniscal injuries of the knee and tibial stress syndrome.
Although for some adults knee pains only start when they first pick up running, experts believe that running alone isn’t usually the single cause of runner’s knee. The majority of those with patellofemoral injuries experience pain due to a combination of both extrinsic and intrinsic factors. This includes things like poor form or training errors when exercising, wearing worn-out or old shoes, exercising on uneven surfaces, muscle imbalances and/or aggravating previous injuries. Runners aren’t the only athletes prone to knees injuries either; those who walk cycle a lot, or anyone performing lots of repetitive bending, jumping or bouncing can also get runner’s knee.
What can you do to help reverse and treat runner’s knee symptoms? Natural treatments for runner’s knee include stretching the legs, strengthening the hamstrings and quadriceps to decrease compensations, seeing a professional for postural alignment adjustments and healing inflamed connective tissue using approaches like prolotherapy/PRP.
What Is Runner’s Knee?
Runner’s knee is another name for patellofemoral pain syndrome (PFPS), which causes inflammation and joint pain in the connective tissue connecting to the knee. Runner’s knee actually isn’t a specific type of injury, rather a term used to describe a collective group of painful knee symptoms. (1)
The kneecap is known as the patella, which is very prone to injury because it bears a lot of our body weight and is commonly impacted by joint deterioration or muscular compensations stemming from the hips, quads and hamstrings. Cartilage loss due to aging, added pressure or weight placed on the knees, or irritation and inflammation from past injuries can all affect the areas surrounding the kneecap. These include the cartilage below the knees (chondromalacia patella), area behind the knees or where the knees meet the thighs.
Running is often associated with knee pain because it causes friction in the joint and tendons that connect the different parts of the upper legs that allow for fluid movement. Connective tissue can loosen or over-stretch when overused in repetitive ways, causing the knee to “wobble” from side to side. This throws off natural alignment.
Wondering if, as the name implies, running or exercising is the actual underlying cause of your runner’s knee symptoms? Overall, studies show mixed results when it comes to the long-term risks associated with frequent running. Some identify an association between frequent distance running and joint or osteoarthritis knee pain, but others have not.
A 2008 study published in the American Journal of Preventive Medicine did not find convincing evidence that even long-distance running over two decades contributed to joint pain indicative of developing osteoarthritis. (2)
The goal of the study was to determine if regular running contributed to joint degeneration in the knees that put middle- to older-aged runners at an increased risk for osteroarthritic-like joint problems when compared with healthy non-runners. After comparing 49 runners with 53 non-runners, radiographic testing showed that runners did not have more prevalent arthritis symptoms in the knees, or more severe cases of osteoarthritis compared to non-runners. Researchers found no significant associations found between osteoarthritis knee pain and gender, education, previous knee injury or mean exercise time, either.
And if you’re a runner, here’s even more good news: there’s much evidence that vigorous exercise (including running) at middle age and beyond is associated with reduced disability in later life, plus a significant “survival advantage” and increased risk for living longer. (3) All different types of exercises are repeatedly shown to improve many health outcomes, including both mental and physical well-being, in people of all ages. Researchers from Stanford University Medical School administered questionnaires regarding exercise habits to 284 runners and 156 healthy controls, and then tracked the subjects’ health markers over 21 years. They found that runners tended to be leaner, less likely to smoke and enjoyed a lowered overall risk of death in older age (called a “survival benefit”).
That being said, other evidence exists showing that running injuries are very common and can affect between 24 to 65 percent of all runners. (4) While not all injuries affect the knees (they also commonly cause pain in the shins, like shin splints, feet or hamstrings), knee pains are a frequent occurrence in most runners at least from time to time. So the bottom line on whether or not you should run? You likely don’t have to give up running if you enjoy it in order to spare your knees, just pay attention to any painful signs or symptoms. As you’ll learn, you can work on preventing knee injuries by fixing your running form, stretching and cross-training to fix muscle imbalances.
Other than running, what types of factors might contribute to runner’s knee? Risk factors for patellofemoral syndrome include: (5)
- Poor form when exercising, especially if you perform exercises that require repetitive motion of the legs. These can include climbing stairs, dancing, plyometrics, and so on.
- Beginning vigorous exercise too quickly, increasing running mileage or intensity too rapidly and wearing worn-out shoes when exercising
- Experiencing trauma or a direct hit to the knees, or falling on the knees
- Having a high BMI, or being overweight/obese
- A history of arthritis, osteoarthritis, or an autoimmune disorder that affects your joints
- Having genetic biomechanical issues that affect joints near the knee, such as those weakening the ankles, feet or hips; knee hypermobility, flat feet, knees that open up the side, and uneven hips can contribute to misalignment and added pressure on the knees for example. (6)
- Being a woman: although not every study has found an association with gender and knee pain, many show that women experience runner’s knee symptoms more often. A study published in the British Journal of Sports Medicine found that women developed runner’s knee twice as often as men. (7) Researchers believe this might be true because women have wider-bearing hips which affects how their body weight is distributed over the knees.
- Being young-to-middle aged: Surprisingly, people under 34 years old have been found to be most likely to develop runner’s knee.
- Being new to exercise: adults who are new to exercising, even those who have been active for less than 8.5 years, tend to develop injuries in the legs most often.
Common signs and symptoms of runner’s knee can include:
- Pain and throbbing in either one or both knees; pain might be dull at times and sharp at others (especially when you are moving)
- Trouble walking or running, climbing, squatting down or bending the knees — movement is most likely to be tough when you’re on uneven terrain or adding extra weight, getting up and down, or when hiking or running up a hill
- Tenderness and sometimes swelling behind, below or radiating outward from the affected knee
- Weakness in the knee, or feeling like it’s “giving out”
- Signs of swelling near the knee, such as fluid retention, redness and heat
- Popping or clicking noises in the knee when you move
Many doctors choose to use injections containing corticosteroid to help reduce inflammation associated with knee pain. While this can help dull throbbing and swelling, it doesn’t fix the underlying problem and won’t necessarily stop symptoms from returning. Steroids also cannot be used long-term and are not well-tolerated by all patients. Even if you do receive injections to decrease knee inflammation, you’ll protect yourself from future injuries or pain if you make a point to stretch, rest from exercise when necessary and improve your posture and form.
1. Stretch and Strengthen the Hamstrings and Quadriceps
According to the Runner’s World website, runner’s knee symptoms can often be traced back to “poorly conditioned quadriceps and tight hamstrings.” (8) If your quadricep muscles (located at the front of your thighs) are weak, more pressure might be placed on your knees and hamstrings as your body is forced to compensate. Weak upper legs can fail to properly support the knee (patella), making it “wobble” and move out of proper alignment. Overtime, the joints connecting to the knee can be stretched out of place and misaligned even though this might feel “normal.” A 2008 study appearing in Dynamic Medicine also found that weak or stiff hamstrings and hips contribute to this same problem. (9)
How can you reduce stress on your knees by improving overall form and posture when running or exercising?
- Add cross-training, specifically exercises to strengthen the whole leg, and stretching to your routine.
- Strengthening and stretching your quadriceps, hips and hamstrings will keep your alignment more centered, your joints/muscles from compensating so much, and your weight distributed more evenly.
- Ideally going forward, you will strength train the legs 2 to 3 times per week, always starting with a dynamic warm-up followed by power and multi-joint exercises, then finishing with isolation exercises.
- However, if performing leg exercises only makes your pain worse, take time to rest and simply lightly stretch the legs before beginning anything new (see more below on rest). Sometimes the exercises below can worsen knee pain if you don’t give the injury time to begin healing.
- Performing lunges and squats
- Side leg lifts and glute bridge lifts
- Tapping into the benefits of yoga
- Swimming and water aerobics
- Light cycling (if you don’t feel pain doing so)
- Standing with your legs straight, bending from the hips to reach for the toes
- While standing, bend one knee and grab for your ankle behind you
- Laying on your back, bending both knees in the air, cross one ankle over the opposite knee, then pull the thigh to release the hip
2. Consider Resting and Giving the Knees a Break
Participating in any exercise without enough rest and recovery time increases the risk of new injuries and worsens symptoms. If you workout frequently in a way that puts a lot of pressure on your knees, your symptoms might in fact be the result of a running injury. Here are signs that you should take a break from running and give the knees time to heal:
- Your pain or symptoms start during or immediately after a run.
- Symptoms started right around the time you started running and decrease when you stop.
- You’ve experienced knee pain while running or exercising to the point that you had to stop midway through. If pain is ever significant enough to force your workout to end, experts recommend stopping or greatly decreasing running mileage and seeking medical assistance. After some time you can begin again, but likely, you need at least several weeks off.
- To help the condition while you rest, try elevating the leg when sitting and avoid standing for very long periods. Place the hurt leg up on a chair with a pillow under the leg, plus ice your knee for 20 to 30 minutes every 3 to 4 hours for several days.
- You might also want to consider wrapping the injured knee to reduce fluid retention. You can ask your doctor for a bandage that he or she recommends or purchase an elastic bandage or strap yourself.
3. See a Professional for Posture Correction Exercises and Treatment
Correcting your form and posture can help reduce stress placed on vulnerable joints (including your knees) and reduce compensations. Consider seeing a physical therapist or chiropractor if suspect that you might have problems with misalignment in your hips, pelvis, ankles or feet. I recommend finding an Egoscue posture therapist and/or seeing a spinal correction chiropractic doctor in your area if symptoms persist. You can also ask your doctor or therapist to recommend stretches to practice at home on your own, or to give you special inserts to place in your shoes for added support.
Here are some posture exercises to get started, too.
4. Consider Soft Tissue Therapies, Including Prolotherapy
Soft tissue therapies can help reduce muscle tension, increase blood flow to damaged tissue, correct posture and even help rebuild new tissue in long-term injuries (depending on the specific kind).
Prolotherapy/PRP is a very useful treatment option for reducing both acute and chronic injuries of the legs. PRP treatments use platelet-rich plasma injections (from a blood sample taken from your own body) that contains platelets, stem cells and growth factors which repair damaged tissue.
Other types of prolotherapy treatments use injections containing substances like dextrose or glucose to trigger localized inflammation in older tissue injuries that stop responding to other treatments and don’t heal on their own. If runner’s knee is an ongoing problem for you, I highly recommend seeing a PRP/prolotherapy practitioner, especially one from the Regenexx clinic which I’ve visited personally.
5. Reduce Inflammation with a Healthy Diet and Supplements
A healthy, anti-inflammatory foods diet provides all the vitamins, antioxidants, minerals and electrolytes you need to help carry out natural healing of the musculoskeletal system. You might not associate a poor diet or food allergies with joint pain and injuries, but being deficient in key nutrients contributes to aging, deterioration, inflammation and reduced blood flow.
To obtain all the healing compounds you need, I recommend increasing your intake of whole foods like fresh veggies and fruit, wild-caught fish and other “clean protein” sources, nuts, seeds, and healthy fats like coconut or olive oil. Additionally you can obtain even more antioxidants by consuming resveratrol supplements, drinking green tea and using medicinal mushrooms like cordyceps. Certain supplements can help protect the health of your joints and connective tissue as you get older, including: turmeric, ginger, berry extracts, bromelain and omega-3 fatty acids.
6. Increase Your Intake of Collagen
In addition to consuming an anti-inflammatory diet, I also highly recommend regularly drinking bone broth, or using protein powder made from bone broth in recipes. Both are natural sources of type 2 collagen, glucosamine, chondroitin and hyaluronic acid, which contain anti-aging effects and aid in tissue repair to protect the joints. Additionally, you can look for bovine collagen powder, which contains type 1 and 3 collagen.
Facts and Figures
- Some studies show that runner’s knee is the most common running injury experienced by adults. Nearly 10 percent of all sports injury clinic visits are due to patellofemoral pain (PFPS); between 25 to 40 percent of running injuries are tied to joint problems of the knees.
- Women seem to be at an increased risk for runner’s knee compared to men.
- Young adults under 34 years old are treated for runner’s knee most often, especially if they are new to exercising and don’t rest enough between workouts.
- Hamstring and quadricep weakness are often at the root of runner’s knee. Studies suggest that 49 percent of athletes with knee pain suffer from quadriceps weakness; 60 percent have quadricep tightness.
- More than two-thirds of all runner’s knee patients can be successfully treated through natural rehabilitation protocols such as stretching, strengthening, resting and icing. Some studies suggest that rehab protocols can reverse 80 to 90 percent of runner’s knee symptoms initially. About 68 percent of adults with runner’s knee maintain symptom improvements for at least 16 months post-rehabilitation.
- In high-risk athletes who exercise often, studies show that a combination of physical training, including cardiovascular training, plyometrics, sport cord drills, strength and flexibility training, may significantly reduce lower body injuries, including runner’s knee, in around 33 percent of patients.
Although most mild-to-moderate cases of runner’s knee should go away on their own with rest, icing and stretching, some cases are more severe and require intervention. Talk to your doctor or an orthopedic if symptoms don’t subside within 2 to 3 weeks with rest. Only rarely does runner’s knee require surgery or long-term care. However, if your knee pain is due to a disorder like osteoarthritis, other treatments other than those mentioned above might be necessary.
- Runner’s knee (patellofemoral pain syndrome or PFPS) causes painful knee symptoms like throbbing, reduced range of motion and trouble exercising.
- Risk factors for developing runner’s knee include: over-exercising (especially with worn-out shoes or poor form), starting exercise too quickly or intensely, having a history of past injuries in the legs that cause musculoskeletal compensations, poor posture and skipping stretching.
- Natural treatments for runner’s knee symptoms include resting, icing and stretching the legs, strengthening the hamstrings and quadriceps, seeing a therapist for postural alignment manipulations and receiving soft tissue treatments including prolotherapy/PRP.