Why Are My Knees Hurting? 5 Common Causes of Knee Pain in Active People


image of person experiencing knee pain

Hopefully, you’ll never suffer from knee pain, but many people do experience painful knees at some point in their lives. On the plus side, staying active can reduce your risk of knee injury by strengthening your quadriceps muscles. However, knee problems are still common among athletes and sedentary folks alike. If you’re feeling twinges in your knees or your knees are downright painful, what’s the likely cause? Here are some of the most frequent knee problems in people who are athletic.

Patellar Tendonitis

This is a common condition marked by wear and tear and overuse of the patellar tendon, the tendon that connects the knee cap to the tibia in the shin. Also known as jumper’s knee, not surprisingly, you see patellar tendonitis most often in athletes who jump as part of their sport. Runners are prone towards it as well. Any type of exercise where the knees sustain high forces on impact can exacerbate the problem, including jumping rope and plyometrics.

What are the symptoms? If you have patellar tendonitis, you may have pain in the front of your knee made worse by running, jumping, or prolonged sitting. Usually, the onset is gradual and you’ll notice stiffening and discomfort in the knees when you wake up in the morning.

The good news is weight training protects against patellar tendonitis by strengthening the quadriceps muscles that support the knee. Correcting tight quadriceps and hamstrings with stretching also helps prevent this frequent cause of knee pain. Avoid overdoing high-impact exercise, especially jumping, when you have active knee pain. To prevent patellar tendonitis, give your knees a few days of rest after a high-impact workout.

Patellofemoral Syndrome

Patellofemoral syndrome is a common condition among runners characterized by pain in the front of the knee. With this cause of knee pain, you feel discomfort because the patella rubs against the femur bone beneath due to damage and breakdown of the cartilage. You might also notice the pain worsens when you go up a flight of stairs, squat, or sit for a long period of time.

Patellofemoral syndrome is a common source of knee pain in young athletes, particularly girls. It’s often related to overuse, but biomechanical factors, like abnormal tracking of the knee cap, may be factors as well. With abnormal tracking, the patella, rather than tracking straight when pulled by the femur, it drifts to one side. This irritates the cartilage underneath and causes discomfort.

The best treatment for patellofemoral syndrome is icing the knees after a workout and modifying your training. It’s best to avoid high-impact exercise until the symptoms improve. Some orthopedists recommend wearing a patella tracking brace for extra support and to reduce abnormal tracking of the kneecap. It also helps to strengthen the vastus medialis, a muscle that runs down the inside of the thigh. Stretching the muscles in the thigh also helps relieve tightness.

Knee Osteoarthritis

Osteoarthritis of the knees becomes more common with age. However, a strength-training program helps prevent the onset of this chronic cause of knee pain. Osteoarthritis arises due to degeneration of the cartilage that cushions and protects the knee. Most people will have some degree of osteoarthritis later in life, although it isn’t always symptomatic.

A major risk factor for osteoarthritis of the knees is being overweight or obese. Keeping your weight down and strength training develops the muscles that support the knee and can reduce your risk of having symptomatic osteoarthritis of the knees. Contrary to popular belief, exercise is beneficial for most people with osteoarthritis of the knees and is typically part of the treatment plan, but if you have significant discomfort, talk to your physician first. Also, wear supportive, padded shoes, warm-up thoroughly, and limit the amount of high-impact exercise you do if you have pain.

Meniscal Tears

Menisci are pieces of cartilage that lie between the femur in the upper leg and the tibia in the lower. These tough but flexible pieces of cartilage reduce the risk of injury by absorbing shock. However, they can also tear, especially if you twist your body or change directions quickly. With age, the menisci weaken and become more prone to tearing. They can weaken to the point that even a minor movement causes a tear.

How do you know if you have one? If you tear a meniscus during sports, you might feel sudden pain. If this happens, ice the knee immediately and see your doctor. An MRI will reveal whether the meniscus is torn and to what degree. Fortunately, many meniscal tears can be treated conservatively with physical therapy, although major ones may require surgery.

Ligament Tears

Ligaments are a type of connective tissue that connects bone to bone. In your knee, you have four main ligaments, two cruciate and two collateral. Ligaments around the knee can be stretched and, in more severe cases, torn. The most dreaded is a tear of the anterior cruciate ligament, a career ender for some athletes. If a ligament tears, you’ll likely have a sudden onset of severe pain, swelling around the knee, and sometimes blood accumulation underneath the skin. It’s important not to bear weight as the joint is unstable when there’s a significant ACL tear or injury. A suspected ligament tear needs immediate evaluation. Don’t try to treat this one at home!

Tips for Keeping Avoiding Knee Pain

·       Always warm up before lifting weights. A dynamic warm-up increases blood flow to the muscles you’ll be working so they’re warm and ready to work.

·       Wear supportive shoes. Look for well-padded footwear that can absorb the shock as your foot hits the ground when you do high-impact exercise. Running shoes have features that increase foot stability and reduce rotation of the food inward when you do high-impact exercise. The insoles should be firm too. If you already have knee pain, visit a podiatrist. They can fit you with orthotics to further support your feet and prevent inward rotation.

·       Work on your form. Sloppy form, especially with squats, increases the risk of knee injury. Lighten up on the weight or use no weight until you know your form is perfected.

The Bottom Line

Even if you’re kind to your knees, they can still become sore and painful. Now, you know what the most likely causes are, but if you have severe or prolonged knee pain, be sure to get evaluated by a medical professional.



Mayo Clinic. “Patellar Tendonitis”
Clin Med Insights Arthritis Musculoskelet Disord. 2014; 7: 27–32.
Sports Injury Clinic. “Knee Pain”


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