Got Pain in the Back of Your Knee? What Causes It and How to Treat It

Learn what can cause pain behind the knee, plus effective ways to prevent and treat it, including at-home exercises from physical therapists.

Published Date: Jan 24, 2023

Our Hinge Health Experts

Mary Kimbrough, PT, DPT
Physical Therapist
Dr. Kimbrough is a Hinge Health physical therapist and board-certified orthopaedic clinical specialist. She also serves as a clinical director of Missouri’s Special Olympics FUNfitness Program.
Jonathan Lee, MD, MBA
Orthopedic Surgeon and Medical Reviewer
Dr. Lee is a board-certified orthopedic surgeon with subspecialty training in hip and knee replacement, as well as advanced clinical expertise in spine care. Dr. Lee oversees the Expert Medical Opinion program at Hinge Health.
Dylan Peterson, PT, DPT
Physical Therapist and Clinical Reviewer
Dr. Peterson is a Hinge Health physical therapist who focuses on developing our exercise therapy programs and member education.

Your knee is one of the hardest-working joints in your body. Thank your knee for your ability to bend, straighten, and rotate — the motions you need to walk, climb stairs, sit, stand, squat, dance, and do just about any activity you can think of. But because of its active role in your movement, the knee can be prone to pain. 

Most knee pain isn’t serious and heals with at-home treatments, but occasionally it signals an injury or issue. Pain in the back of the knee is common and can be associated with many of the typical problems people experience with their knees. 

Here are the most common causes of pain behind the knee, when to see a doctor, and how to treat it. Plus, learn effective ways to prevent knee pain from breaking your stride in the future by following simple lifestyle changes and at-home exercises from our physical therapists.

What Causes Pain in the Back of the Knee?

Knee pain is most commonly caused by low-grade, non-severe issues like muscle strain, says Mary Kimbrough, PT, DPT, OCS, a physical therapist at Hinge Health. Here are other issues that could lead to pain in the back of the knee.

Overworked muscles. When your muscles work harder than usual (like when you exercise), your muscles become stronger and more resilient. But sometimes, if you do too much too often, you can overdo it and become temporarily injured. The hamstring, the calf, and a small stabilizing muscle known as the popliteus muscle are the top sources of muscle strain behind the knee, resulting in an aching, tender feeling. The risk of muscle strains increases with a lack of warm-up and intense training activities, and in people with less flexibility and muscle strength.

Runner's knee. Patellofemoral syndrome, or runner’s knee, is one of the most common overuse injuries affecting the knee. It feels like a dull ache behind or around the kneecap that gets worse with movement (like climbing stairs) or prolonged sitting. 

Ligament issues. Ligaments are thick, fibrous tissues that connect your bones to each other. They support and stabilize the knee, and can be prone to overstretching. The PCL (posterior cruciate ligament) is a common culprit in pain behind the knee. The PCL works with its cousin the ACL (anterior cruciate ligament) to keep the knee stable during front-to-back motion. PCL tendons may be injured if the knee suffers a significant blow while bent (the classic example: a car crash in which your knee hits the dashboard). However, the PCL is often hurt in conjunction with other structures, like the ACL or meniscus. PCL tears tend to heal with conservative treatments, but some may benefit from surgery.

Osteoarthritis. The cartilage that cushions your knee naturally changes as you age, which can lead to pain and stiffness. One study found the back of the knee was one of the top pain zones for knee osteoarthritis. 

Meniscus tear. The menisci are cushioning cartilage “shock absorbers” that sit in the knee joint. The meniscus can wear slowly over time or be torn suddenly during a sports injury, leading to pain, stiffness, and a sense of the knee catching or locking. Meniscus tears don’t typically present with isolated pain in the back of the knee, but the issue is common enough that your doctor may want to rule it out.

Baker’s cyst. If there’s been swelling in the knee, it will sometimes collect as a fluid-filled cyst.  “You might touch the back of your knee and notice a little bump or firm nodule, which is causing discomfort,” says Dr. Kimbrough. Baker’s cysts are common and often occur when another irritating condition, like osteoarthritis, is present. 

Treatments for Pain in the Back of the Knee

Knee pain often gets better on its own or with active pain treatment methods like exercise, movement, and physical therapy. 

Do physical therapy. A physical therapist can assess the musculoskeletal issues involved in pain behind your knee and design customized exercises to improve strength, flexibility, and mobility where you need it. Physical therapy exercises typically target the injured part (the knee), as well as structures that support it from above and below. “People often say, ‘Why am I working my hip? Why am I doing balance exercises for my ankle? I’m here for my knee!’ It’s because all these parts work together to support healthy knee function,” says Dr. Kimbrough. 

You can see a physical therapist in person or use a program like Hinge Health to access a PT via telehealth/video visit.

Modify your activity. If you’re experiencing an uptick in acute pain, avoid putting weight on the knee or moving around more than necessary. But remember that healing happens mostly from moving, not resting. Physical movement helps your joint heal, so ease back into your routine as soon as you can, advises Dr. Kimbrough. Many people find that physical therapy helps them get over some natural fear of moving through pain. 

"People are cautious about overdoing it. As movement experts, physical therapists can help you find that sweet spot — doing the right moves in the right dose — so your exercise is appropriate for where you are in the healing process."
Mary Kimbrough, PT, DPT, OCS

Use ice. Apply cold packs for 20 minutes several times a day to help ease discomfort and swelling. Here’s more about when to use ice vs. heat.

Try taping. Athletes recovering from runner’s knee experienced less pain while stepping down when athletic tape was applied above and below the knee, forming a supportive “X” behind the knee. Ask your physical therapist if taping is a good idea (and what techniques to try) for your condition.

Take over-the-counter (OTC) medication. Pain relievers such as ibuprofen (Advil, Motrin), naproxen (Aleve), and acetaminophen (Tylenol) can be helpful for knee pain. It’s important to make sure that you are safely able to take these medications, based on your medical history.

Surgery. Some treatments for serious injuries, like an ACL or meniscus tear, or chronic conditions (such as osteoarthritis) may involve surgery, especially if other treatments haven’t helped you enough to return to everyday activities. Whether or not you are a candidate depends on the severity of your pain and disability, as well as the nature of your condition. Your doctor may also suggest that you go to physical therapy for “prehab” before a procedure like an ACL repair or total knee replacement, says Dr. Kimbrough. “We work on strengthening the structures around the knee because those are going to be important after surgery as well.”

How to Prevent Pain in the Back of the Knee

Here are key habits and exercise tips to keep the knee joint strong and healthy.

Protect yourself from falls. If you play an intense or high-contact sport, focus on good training techniques, wearing protective gear (including appropriate footwear), and working on safe surfaces (avoiding wet or icy terrain, for instance). A sore, painful joint is less able to absorb sudden shifts in movement, so accept that you may need to stick to a slower, steady gait, or even use walking aids, as you heal.

Walk or find other simple ways to stay active. “We know that exercise is good for overall health and for joint health. Just staying physically active can prevent knee problems,” says Dr. Kimbrough. The American College of Sports Medicine recommends 150 minutes of moderate-intensity aerobic activity a week (for example, 30 minutes a day, five days a week). Aim for a mix of cardio, strength training, and stretching. Strong, flexible muscles can help prevent overuse injuries.

Take frequent breaks throughout the day. Studies suggest there’s a connection between knee pain and back health. Physical therapists prefer not to “demonize” any particular posture. But they do encourage us not to hold any one position for too long (think: sitting and looking down at your computer or phone for hours). 

“Take microbreaks — say, every 30 minutes to an hour you stand up, stretch, or walk to get a glass of water. Just do anything to break up staying in one position for a long period of time,” says Dr. Kimbrough. Because it’s so easy to keep your head down and get your work done as fast as possible, she recommends setting an alarm for every 45 minutes and committing to a small movement or change in position. “Otherwise, it’s easy to look up and realize that five hours  passed and you forgot to move.”

Reach or maintain a healthy weight. A study of more than 8,000 adults found a strong association between knee pain and weight gain. But the upside is that losing 10% of body weight has also been found to improve pain and function in people who are overweight or obese and have knee osteoarthritis. 

Knee Pain: A Hinge Health Perspective

We know knee pain can feel scary and debilitating. If there’s one thing we want you to know, it’s this: There are always things you can do to get back to doing what you love and get pain relief.

You may have some muscle strain. You may have arthritis or ligament or meniscus injuries. You'll read about these possible causes below but remember: No matter what's involved in your knee pain, you're not stuck. Your condition is not impossible to change. How do we know this? Studies show that less than 50% of people with osteoarthritis on X-rays have knee pain. Same goes for a majority of people who had meniscus tears on an MRI: They didn’t have any pain, stiffness, or aching.

This means your imaging findings do not always correlate with your symptoms. It's a possible contribution to your pain, but it's often not the only factor. You may not be able to control every issue involved in your knee pain, but you do have the power to change some important things. You can always do something to improve your knee pain, and that often starts with moving more. As our Hinge Health care team says, movement is medicine.

Strengthening Knee Exercises for Pain Behind the Knee

To prevent pain behind your knee, it’s a good idea to build muscle strength in your legs. The exercises below can help. “I recommend doing these two to three times per week to see how your body reacts,” says Dr. Kimbrough. “Gradually increase to doing them daily as tolerated. Let symptoms be your guide. Some discomfort is okay, but if pain increases or worsens, talk to your provider before going any further.” If you’re concerned about knee pain or have any issues under our “When to See a Doctor” section (below), see a healthcare provider before getting started.

Squats

This move strengthens the structures that support the knee from above and below. It works the hips, the glute muscles (in the back of the hips), and the front thigh muscles (the quadriceps).

Squats

This move strengthens the structures that support the knee from above and below. It works the hips, the glute muscles (in the back of the hips), and the front thigh muscles (the quadriceps).

Squats

This move strengthens the structures that support the knee from above and below. It works the hips, the glute muscles (in the back of the hips), and the front thigh muscles (the quadriceps).

Squats

This move strengthens the structures that support the knee from above and below. It works the hips, the glute muscles (in the back of the hips), and the front thigh muscles (the quadriceps).

Standing Hamstring Curl

This strengthens the back thigh (hamstring) muscles, which attach to the back of the knee from above.

Standing Hamstring Curl

This strengthens the back thigh (hamstring) muscles, which attach to the back of the knee from above.

Standing Hamstring Curl

This strengthens the back thigh (hamstring) muscles, which attach to the back of the knee from above.

Standing Hamstring Curl

This strengthens the back thigh (hamstring) muscles, which attach to the back of the knee from above.

Calf Raise

This strengthens the calf muscle, which attaches into the back of the knee from below.

Calf Raise

This strengthens the calf muscle, which attaches into the back of the knee from below.

Calf Raise

This strengthens the calf muscle, which attaches into the back of the knee from below.

Calf Raise

This strengthens the calf muscle, which attaches into the back of the knee from below.

When to See a Doctor

Most knee pain involves muscle strains or injuries that heal with conservative care. But if you’ve had a traumatic blow to the knee or have a structural issue like a ligament tear, you’ll need a doctor’s guidance. See a healthcare professional if you notice any of the following:

  • Inability to bend your knee back all the way 

  • A feeling of catching or locking in the knee

  • A high level of pain or very sharp pain

  • Episodes of your knee “giving out” on you

  • You don’t feel safe or stable standing on or moving your leg 

  • You’re limping or cannot walk normally

  • Swelling around the knee 

  • Pain does not improve with at-home treatments

PT Tip: Do ‘Deskercise’ for Flexibility

The hamstring muscles in the back of your thighs connect to the back of the knee. Sitting all day for your job can make the hamstrings tight and less flexible, contributing to pain, says Dr.  Kimbrough. For a quick stretch, do leg kicks while seated. From a seated position, kick your leg straight out and hold it for 10 seconds. This stretches and lengthens the hamstring. Do this, alternating legs, as part of the posture breaks that we recommend you take every 45 minutes or so to break up long periods of sitting.

Learn More About Hinge Health for Knee Pain Relief

Our digital programs for back and joint pain are offered for free through benefit providers. Click here to see if you’re eligible.

This article and its contents are provided for educational and informational purposes only and do not constitute medical advice or professional services specific to you or your medical condition.

Frequently Asked Questions  

Can knee pain be related to the back?  

As the children’s teaching song goes, the knee bone connects to the thigh bone, which connects to the hip bone, which connects to the back bone. The song is a catchy way to explain the very real concept that our body parts are interdependent and work together. That means pain in one area can be related to what’s happening in seemingly distant parts. One 2019 study of almost 5,000 adults over age 50 found that those who experienced low back pain were 1.6 times more likely to develop new knee pain within five years. Why? One theory says that people who have back pain adjust their movements so that other weight-bearing joints like the knee carry more load in their daily activities, creating a domino effect of strain. Another well-known connection between knee and back pain is the sciatic nerve, which originates in the lower spine and travels down the back of the leg. If you have sciatica, pain from irritated nerves in the lower back can travel down to the knee or beyond.  

How do I know if my knee pain is serious? 

Most cases of knee pain stem from overuse or repetitive-use injuries like muscle strains or tendinitis that heal with at-home treatment. But there’s more reason to be concerned if you have signs of structural injuries. If you feel a locking or popping sensation in the knee, or burning or tingling pain that travels to other areas, or if you can’t fully bend your knee, see a healthcare provider. If your pain continues to get worse with normal activity, you could have a condition like osteoarthritis, which benefits from holistic treatment like regular physical activity and other lifestyle changes.

Get evaluated if your knee pain began after any kind of trauma or impact, like a fall or an intense sports game. If your pain is severe or your leg feels unstable at times, see a healthcare provider as soon as possible. 

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