Cracking Knees: Harmless or a Warning Sign?

Snap, Crackle, Pop — From Your Knees?

Ever stood up and heard your knees crack or pop? You’re not alone. Knee noises — known as crepitus — are very common, especially during squatting, kneeling, or walking up stairs. In fact, studies suggest that up to 99% of people experience knee sounds at some point. While the noise can be unsettling, it’s usually not a sign of injury or damage. But how do you know when it’s normal and when it’s not? Understanding the difference can help reduce anxiety and unnecessary treatment costs.

What Causes Cracking in the Knees?

Knee cracking can come from a few harmless sources:

• Air bubbles forming and popping in the joint fluid (like cracking knuckles)
• Movement of tendons or ligaments over bony areas
• Slight rubbing of joint surfaces during movement

These sounds are often painless and not linked to any underlying damage. However, if the cracking is loud, painful, or associated with swelling, locking, or giving way, it may point to:

• Cartilage wear (such as in early osteoarthritis)
• Patellofemoral dysfunction (kneecap tracking problems)
• Meniscus injury (a tear in the knee’s shock absorber)

What Should You Do About It?

If your knees crack but don’t hurt, there’s usually nothing to worry about, and no treatment is needed. But if cracking is paired with pain or instability, a physiotherapist can help with:

• Strength training for the quads, glutes, and hips
• Stretching tight muscles like calves or hamstrings
• Correcting movement patterns during squats, stairs, and lunges
• Manual therapy or taping if tracking is an issue

Knee-friendly activities like cycling, swimming, or walking can keep you active while improving strength and control.

What Doesn’t Help or Isn’t Needed?

Routine scans like MRIs or X-rays are rarely necessary unless there’s a significant injury history or red flags (e.g. swelling, locking, or sharp pain). In most cases, scans only show age-related changes that aren’t linked to symptoms.

Passive treatments like ultrasound or electrical stimulation don’t address the underlying biomechanics. Surgery for clicking alone is not recommended unless it’s linked to a clear structural problem (e.g. large meniscus tear).

What’s New in Knee Health?

Modern rehab focuses on individualised strengthening programs, often with the help of movement assessments and app-guided home programs. There’s growing awareness that knee sounds without pain are normal, helping reduce fear and over-treatment. Some clinics use motion tracking to detect subtle movement faults in people with noisy knees that may be linked to joint overload.

How to Keep Your Knees Healthy and Quiet

• Strengthen your quads, hamstrings, and glutes
• Use good technique with stairs, squats, and kneeling
• Maintain a healthy weight to reduce joint stress
• Avoid sudden changes in training intensity
• Don’t let occasional cracks stop you from moving