Why Does My Knee Click When I Bend It? Understanding Patellofemoral Pain

Have you ever bent down to pick something up, stood up from a chair, or walked up the stairs and heard a clicking or popping sound coming from your knee? Knee clicking is common, and while the noise can be unsettling, it doesn't always mean something is wrong.

Knees make all kinds of noises as we move, from clicking and popping to cracking and grinding. Most of the time these sounds aren't a concern, especially when they happen without pain. But if clicking comes with discomfort around the kneecap, particularly during squats, stairs, or exercise, patellofemoral pain may be one possible explanation.

At Shift Physiotherapy & Wellness in Edmonton, our physiotherapists help people understand what's contributing to their knee pain and develop treatment plans for comfortable movement.

TL;DR: What You Should Know About Knee Clicking

• Knee clicking is common and doesn't necessarily indicate injury or joint damage.

• Painless clicking is usually harmless. Healthy knees naturally make noise.

• Clicking with pain, swelling, locking, or difficulty moving may need assessment.

• Patellofemoral pain syndrome (PFPS) causes pain around or behind the kneecap, often during squats, stairs, and running.

• Physiotherapy can help assess symptoms, build strength, and support your return to activity.

Why Does My Knee Click When I Bend It?

Your knee is a complex joint made up of bones, cartilage, ligaments, tendons, and other tissues that work together as you move. Every time you bend or straighten your knee, these structures move and interact. Sometimes that movement produces a clicking, popping, or cracking sound.

The medical term for joint noise or a crackling sensation is crepitus. You might notice it when squatting, using stairs, standing up, running, straightening your leg, or getting in and out of a vehicle.

1. Gas Bubbles Within the Joint

Your knee contains synovial fluid that helps lubricate the joint. Changes in joint pressure during movement can cause gas-filled cavities to form, sometimes producing popping or cracking sounds. These sounds are generally harmless and don't necessarily mean the joint is damaged.

However, not all knee noises are caused by gas bubbles. Clicking, popping, and cracking can have several different causes depending on the type of sound and when it occurs.

2. Tendons and Ligaments Moving Over Nearby Structures

Tendons and ligaments help support and control your knee. As you bend or straighten it, a tendon can move over a nearby bony structure and produce a snapping or clicking sensation. If the motion is painless and your knee functions normally, it often isn't a concern.

3. Movement Around the Kneecap

Your kneecap, or patella, sits at the front of your knee and glides within a groove at the end of your thigh bone. This movement may produce clicking or grinding sensations. Noise alone doesn't mean damage, but if you also have pain around the front of your knee, patellofemoral pain may be one explanation.

4. Changes Within the Knee Joint

Sometimes knee clicking is associated with changes in cartilage or other joint tissues. Conditions such as osteoarthritis and meniscus injuries may cause clicking or catching, especially alongside pain, swelling, or restricted movement. Clicking alone cannot diagnose these conditions.

What Is Patellofemoral Pain Syndrome?

Patellofemoral pain syndrome, also called PFPS or runner's knee, is a common cause of pain around or behind the kneecap. Your patella moves through a groove on your femur as you bend and straighten your leg. The forces through this joint change depending on the activity.

Squatting, running, and climbing stairs place greater demands on the patellofemoral joint. When tissues around the kneecap become sensitive to these demands, pain can develop. It often begins gradually and may relate to changes in activity, muscle strength, movement patterns, or load tolerance.

Some people with patellofemoral pain experience clicking or grinding, but clicking isn't required for a diagnosis and having a noisy knee doesn't mean you have PFPS.

What Are the Symptoms of Patellofemoral Pain?

Patellofemoral pain usually causes discomfort around or behind the kneecap. It often becomes more noticeable when the knee bends while bearing weight.

• Aching around the front of the knee

• Pain walking up or down stairs

• Discomfort during squats or lunges

• Pain when running or jumping

• Pain after sitting with bent knees for a long time

• Clicking or crunching that may occur alongside pain

Symptoms vary. Some people only notice discomfort during exercise, while others feel it climbing stairs or getting up from a chair.

Why Does My Knee Click and Hurt When I Squat?

Squatting increases the demands on your knees, hips, and surrounding muscles. The deeper you squat, the greater the force can become through the patellofemoral joint. If the kneecap area is sensitive, you might notice pain as you bend deeply or return to standing.

Clicking during a squat is not necessarily harmful by itself. If pain consistently accompanies the noise, a physiotherapist can assess your knee movement, strength, exercise routine, and activity levels.

Why Does My Knee Click When Going Up or Down Stairs?

When climbing stairs, the quadriceps muscles at the front of the thighs help straighten your knees to lift your body. Going downstairs requires those muscles to control your descent. Both movements place demands on the kneecap joint.

People with patellofemoral pain may notice discomfort in either direction, particularly going downstairs. Painless noise usually doesn't require treatment, but pain or instability is worth having assessed.

Does Knee Clicking Mean I Have Arthritis?

Not necessarily. Clicking, cracking, and crunching sounds don't automatically mean you have arthritis. Osteoarthritis can involve changes to cartilage and surrounding joint tissues, and some people with it experience crepitus. Many people without arthritis also have noisy knees.

Clicking alone doesn't tell us whether arthritis or cartilage damage is present. Other signs, such as persistent pain, stiffness, swelling, or difficulty moving, may help guide an assessment.

Understanding knee cartilage: This illustration shows cartilage changes associated with chondromalacia patella. However, patellofemoral pain syndrome doesn't always involve cartilage damage, and knee clicking alone doesn't necessarily indicate a problem with your cartilage.

If you're concerned about changes in knee health, a physiotherapist can discuss whether further medical evaluation may be appropriate.

How Can Physiotherapy Help With Patellofemoral Pain?

When clicking comes with pain, physiotherapy can help you understand what contributes to your symptoms. At Shift Physiotherapy & Wellness in Edmonton, we assess how your knee functions, what aggravates it, and what may help you move more comfortably.

Understanding Your Knee Pain

Your physiotherapist will ask about your symptoms, medical history, and activity levels. They may assess knee movement, quadriceps and hip strength, balance, squatting, stair climbing, swelling, and joint stability. The goal is to identify whether your symptoms are consistent with patellofemoral pain or another condition.

Strengthening the Muscles Around Your Knee

Quadriceps and hip strengthening are important parts of rehabilitation for patellofemoral pain. Depending on your symptoms and goals, a physiotherapist may recommend seated knee extensions, sit-to-stands, step-ups, modified squats, hip strengthening, or progressive single-leg exercises.

Exercises are adjusted to your current tolerance. The goal is to make everyday activities more comfortable, not necessarily to eliminate all knee noises.

Adjusting Activities That Aggravate Your Knee

You might benefit from temporarily reducing squat depth, changing your running distance, or adjusting exercise intensity while symptoms improve. This doesn't usually require stopping all physical activity. Maintaining an appropriate level of movement can support recovery.

Improving Movement and Activity Tolerance

Your physiotherapist may help adjust how you squat, climb stairs, or perform single-leg movements. Depending on the assessment, strategies such as patellar taping may offer temporary symptom relief alongside strengthening.

Learn more about physiotherapy treatments at Shift in Edmonton.

What Can You Do at Home for Knee Clicking and Pain?

• Keep moving within your comfort level. Painless clicking alone doesn't usually require you to stop activity.

• Adjust exercises that hurt. Try reducing squat depth, running distance, or intensity temporarily.

• Build strength gradually around the knee and hips.

• Avoid repeatedly forcing your knee to pop. Focus on comfortable movement.

• Watch for other symptoms, including swelling, persistent pain, locking, or instability.

Can You Continue Exercising if Your Knee Clicks?

In many cases, yes. If your knee clicks without pain, swelling, or loss of movement, you can generally continue normal activities. Noisy knees aren't necessarily unhealthy knees.

If you have patellofemoral pain, you may still be able to exercise with modifications. A physiotherapist can help you select activities and progress gradually.

How Long Does Patellofemoral Pain Take to Improve?

Recovery varies depending on your symptoms, activity level, and how long you've had discomfort. Some people notice improvement after several weeks of suitable strengthening and activity changes. Longer-standing pain may require more time.

Building strength and load tolerance takes consistency. Improvement doesn't necessarily mean your knee becomes silent. Clicking may continue even after pain improves.

When Should You See a Physiotherapist for Knee Clicking?

Occasional painless clicking generally isn't a concern. Consider an assessment if:

• Clicking is consistently accompanied by pain.

• Squats, stairs, or running have become uncomfortable.

• Your knee feels swollen or unusually stiff.

• You struggle to bend or straighten the knee.

• Pain returns whenever you exercise.

• You're avoiding activities because of concern about your knee.

If your knee locks so you cannot straighten it, or you have sudden major swelling, severe pain, or difficulty bearing weight following an injury, seek prompt medical assessment.

Get Support for Knee Pain at Shift Physiotherapy & Wellness in Edmonton

Hearing your knee click when you bend it can be surprising, but it doesn't automatically mean something is wrong. For many people it's simply a normal part of movement. When noises occur alongside pain, especially around the kneecap during squats or stairs, understanding the cause can be useful.

At Shift Physiotherapy & Wellness in Edmonton, our physiotherapists can assess your knee, identify contributing factors, and build a treatment plan around your goals, whether you're returning to running, getting comfortable on stairs, or simply moving with more confidence.

Ready for an assessment? Explore Shift's physiotherapy services and get in touch to book.

Frequently Asked Questions About Knee Clicking and Patellofemoral Pain

Is it normal for my knee to click when I bend it?

Yes. Clicking is common and often harmless when it isn't accompanied by pain, swelling, or limitations. Joint noises may come from gas-related changes or the movement of tendons and other tissues.

Why does my knee click but not hurt?

Painless clicking can happen as the structures around your knee move. If your knee is stable, moves normally, and doesn't cause discomfort, the sound itself usually isn't concerning.

Can patellofemoral pain syndrome cause knee clicking?

Some people with patellofemoral pain notice clicking, grinding, or crunching, but pain around or behind the kneecap is the defining symptom. Clicking alone doesn't mean you have PFPS.

Does knee clicking mean my cartilage is damaged?

Not necessarily. Clicking occurs in many healthy knees and doesn't automatically indicate cartilage damage. Pain, swelling, or restricted movement may warrant assessment.

Why does my knee crack when I squat?

Squatting moves the kneecap, tendons, and other tissues, which can create sounds. If squatting is also painful, patellofemoral pain or another condition may be contributing.

Should I stop exercising if my knee clicks?

Not usually if the clicking is painless and there is no swelling. If exercise hurts, adjust the intensity or movement range and seek advice if symptoms persist.

Can physiotherapy help with patellofemoral pain syndrome?

Yes. Physiotherapy often includes progressive quadriceps and hip strengthening, activity modifications, and movement education to improve comfort and function.

How do I stop my knee from clicking?

Not all clicking needs treatment. If it's painless, there's usually no need to stop the noise. If pain occurs, rehabilitation can address symptoms, though some clicking may remain.

Do I need a doctor's referral for knee physiotherapy in Edmonton?

No. In Alberta, you can generally book directly with a physiotherapist. Some insurance plans may require a referral for reimbursement, so check your benefits.