Medically reviewed by David Ozeri, MD Key Takeaways Cracking bones is actually just the sound of joints popping and is usually not a reason to worry. Painful joint cracking may be a sign of injury or ...

Medically reviewed by Cara Beth Lee, MDKey TakeawaysKnee popping can be harmless and caused by air bubbles in the joint.Knee popping with pain could mean an injury like cartilage damage or a meniscus ...